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THE 


FOSSIL  TURTLES 


OF 


NORTH    AMERICA 


BY 


OLIVER  PERRY  HAY 


WASHINGTON,  D.  C. 
Published   by  the  Carnegie  Institution  of  Washington 

1908 


Carnegie  Institution  of  Washington,  Publication  No.  75 


ISAAC  H.   BLANCHARD  COMPANY 
NEW  YORK 


QE 

g(oZ 

H3 


PREFACE. 


In  this  treatise  on  the  Fossil  Turtles  of  North  America  there  are  described 
266  species,  of  which  76  are  regarded  as  hitherto  unknown  to  science.  In  the 
preparation  of  this  work  the  writer  has  had  access  to  most  of  the  collections  which 
contain  remains  of  North  American  fossil  turtles.  The  most  important  of  these 
collections  is  that  of  the  American  Museum  of  Natural  History,  in  New  York. 
In  this  are  found  many  of  the  specimens  described  by  Professor  E.  D.  Cope, 
including  many  of  his  types.  In  addition  to  these,  large  numbers  of  turtles  have 
been  brought  together  by  the  expeditions  sent  out  by  this  museum  during  the  past 
fifteen  years.  Free  access  has  been  given  the  writer  to  the  materials  in  the  United 
States  National  Museum,  where  there  are  many  of  the  specimens  described  by 
Dr.  Joseph  Leidy  and  Professor  Cope;  to  those  of  the  Academy  of  Natural  Science 
of  Philadelphia,  where  are  found  other  materials  rendered  precious  by  the  labors 
of  the  authors  just  mentioned;  to  those  of  the  Carnegie  Museum,  Pittsburgh; 
the  Field  Natural  History  Museum,  Chicago;  the  University  of  Kansas,  Lawrence; 
the  University  of  Texas,  and  the  University  of  Nebraska.  At  Yale  University 
the  writer  has  been  permitted  to  study  and  describe  valuable  materials  brought 
together  by  Professor  O.  C.  Marsh,  besides  other  specimens  which  form  the 
types  of  species  described  more  recently  by  Dr.  George  R.  Wieland.  Thru  the 
courtesy  of  Professor  W.  S.  Valiant  some  of  Dr.  Leidy 's  types  preserved  at  Rutgers 
College  were  made  accessible.  Specimens  for  study  have  been  sent  to  the  writer 
from  most  of  the  museums  mentioned;  also  from  the  University  of  Chicago,  by 
Mr.  S.  W.  Williston;  from  the  University  of  California,  by  Dr.  J.  C.  Merriam; 
from  the  Geological  Survey  of  Canada,  by  Mr.  L.  M.  Lambe;  and  from  the 
Vanderbilt   University,  Nashville,   by   Professor  L.   C.   Glenn. 

It  has  been  the  author's  earnest  wish  to  see  all  the  types  of  the  hitherto  described 
species;  and  most  of  these  have  come  under  his  notice.  Unfortunately  some  are 
without  doubt  utterly  lost;   others  have,  for  the  time,  disappeared  from  view. 

The  author  has  endeavored  to  illustrate  as  fully  as  possible  the  species  described. 
Whatever  mayprove  to  be  the  little  or  greatvalue  of  the  text, the  writer  can  commend 
the  illustrations.  By  far  the  greater  number  of  the  figures  of  the  plates  are  from 
photographs  which  were  taken  at  the  American  Museum  of  Natural  History  by 
Mr.  A.  E.  Anderson.  Other  photographs  and  drawings  have  been  furnished  by 
the  Geological  Survey  of  Canada  thru  Mr.  L.  M.  Lambe;  others  by  Dr.  George  R. 
Wieland,  of  the  Yale  University  Museum;  others  by  Dr.  W.  J.  Holland,  director 
of  the  Carnegie  Museum,  Pittsburgh.  The  photographs  of  Basilemys  sinuosa 
came  from  the  Field  Natural  History  Museum,  thru  Dr.  E.  R.  Riggs.  A  consider- 
able number  of  the  drawings  found  in  the  plates  were  prepared  many  years  ago, 
for  the  late  Dr.  George  Baur,  by  the  United  States  Geological  Survey;  thru  the 
courtesy  of  the  Survey  these  were  placed  in  the  hands  of  the  writer.  The  major- 
ity of  the  drawings  that  appear  in  the  text  were  executed  by  Mrs.  Lindsay  Mor- 
ris Sterling,  artist  in  the  department  of  vertebrate  paleontology  in  the  American 
Museum  of  Natural  History.    A  number  of  these  text-figures  are  the  work  of  Mr. 


Ill 


IV  PREFACE. 

R.  Weber,  of  the  same  museum.  Most  of  the  wash-drawings  that  appear  in  the 
plates  were  produced  by  Mr.  Erwin  C.  Christman  of  the  American  Museum  of 
Natural  History. 

The  thanks  of  the  author  are  due,  first  of  all,  to  the  Carnegie  Institution  of 
Washington  for  the  support  it  has  given  him  in  the  preparation  of  this  monograph; 
in  the  next  place,  to  Professor  H.  F.  Osborn,  of  the  American  Museum  of  Natural 
History,  New  York,  for  the  opportunity  to  use  the  materials  in  that  museum; 
finally,  to  all  the  persons  and  institutions  above  mentioned  and  others  who  have 
contributed  in  any  way  to  whatever  there  may  be  of  value  in  this  work. 

It  is  not  believed  to  be  necessary  to  append  a  list  of  the  papers  and  memoirs 
consulted  in  the  preparation  of  this  monograph;  inasmuch  as  the  writer's  Bibliog- 
raphy and  Catalogue  of  the  Fossil  Vertebrata  of  North  America,  Bulletin  179  of 
the  United  States  Geological  Survey,  records  the  literature  of  the  subject  up  to  the 
year  1901  and  the  important  writings  since  published  are  cited  in  the  text  of  this 
monograph. 

Washington,  November  20,  1907. 


THE  FOSSIL  TURTLES  OF  NORTH  AMERICA. 


ON  THE  SOURCES  OF  OUR  KNOWLEDGE  OF  THE  FOSSIL  TURTLES   OF 

NORTH  AMERICA. 

The  study  of  the  fossil  turtles  of  North  America  began  in  1851,  when  Dr. 
Joseph  Leidy  described,  under  the  names  Stylemys  nebrascensis,  Testudo  lata, 
Emys  hemispherica,  and  Emys  oweni,  the  extremely  common  fossil  turtle  of  the 
Oligocene  Badlands  of  the  present  state  of  South  Dakota,  then  a  part  of  the  Terri- 
tory of  Nebraska.  It  is  true  that  in  1842  Dr.  Richard  Harlan  had  described  and 
figured  (Amer.  Jour.  Sci.,  xliii,  p.  144,  pi.  iii,  figs.  2,3)  as  Chelonia  coiiperi  a  bone 
which  he  believed  to  be  the  femur  of  a  large  sea-turtle;  but  it  is  quite  certain  that 
the  bone  was  no  part  of  any  turtle.  Dr.  Leidy  continued  at  intervals  up  to  1889  to 
describe  new  species  of  fossil  turtles.  Most  of  Dr.  Leidy's  shorter  papers  appeared 
in  the  Proceedings  of  the  Philadelphia  Academy,  but  his  most  important  illustrated 
works  on  the  subject  are  found  in  D.  D.  Owen's  Geological  Survey  of  Wisconsin, 
etc.,  1852;  in  the  sixth  volume  of  the  Smithsonian  Contributions  to  Knowledge, 
1854;  and  in  the  first  volume  of  the  monographs  of  Hayden's  Geological  Survey 
of  the  Territories,  1872.  Professor  E.  D.  Cope  began  his  publications  of  species 
of  fossil  turtles  in  1867;  his  last  paper  containing  matter  on  the  subject  was  pub- 
lisht  in  1899,  after  his  death.  His  papers  on  the  subject  are  numerous  and  will 
be  found  cited  in  the  writer's  Bibliography  and  Catalogue  of  the  Fossil  Vertebrata 
of  North  America,  1902.  Cope's  most  important  expositions  of  the  turtles  are  to 
be  found  in  the  fourteenth  volume  of  the  Transactions  of  the  American  Philosophical 
Society,  1869  and  1870;  in  the  second  volume  of  the  Hayden  Survey  monographs, 
1875;  in  volume  four  of  Wheeler's  Survey  West  of  the  looth  Meridian,  1877;  and 
in  the  third  volume  of  the  monographs  of  the  Hayden  Survey,  1884. 

Professor  O.  C.  Marsh  described  only  three  species  of  fossil  turtles.  No  new 
fossil  species  are  to  be  credited  to  Dr.  George  Baur,  but  he  was  the  author  of  a 
number  of  papers  which  made  important  additions  to  our  knowledge  of  their 
structure  and  relationships.  Dr.  S.  W.  Williston  and  Dr.  E.  C.  Case  have  con- 
tributed a  number  of  valuable  papers  on  the  subject,  especially  on  the  turtles 
derived  from  the  Niobrara  beds  of  Kansas.  Dr.  George  R.  Wieland  has  given 
especial  attention  to  the  marine  turtles  of  the  Upper  Cretaceous;  and,  especially, 
he  has  described  that  remarkable  chelonian  monster  Archelon  ischyros. 

Other  authors  who  have  busied  themselves  more  or  less  with  the  North  American 
chelonian  population  of  past  times  are  J.  Z.  Gilbert,  L.  M.  Lambe  of  the 
Canadian  Geological  Survey,  Dr.  F.  B.  Loomis,  W.  J.  Sinclair,  E.  S.  Riggs,  and 
O.  P.  Hay.  The  results  of  the  studies  of  the  authors  mentioned  are  that  more  than 
260  species  of  fossil  turtles  are  now  known  from  the  geological  deposits  of  North 
America;  the  nearly  complete  structure  of  a  considerable  number  of  these  has 
been  determined  and  much  of  that  of  others;  and  much  light  has  been  gained 
regarding  the  history  and  relationships  of  the  members  of  the  order.  Undoubtedly 
many  additional  species  will  be  discovered  as  the  years  pass  away  and  species  now 
known  only  from  a  few  bones  will  become  far  better  known. 

I 


4  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

costals  as  rib-heads,  which  articulate  with  the  vertebral  centra.  At  the  front  of  the 
shell  each  rib-head  articulates  with  two  centra,  at  their  junction  with  each  other; 
more  posteriorly,  the  rib-head  falls  farther  and  farther  behind  the  intervertebral 
articulation.  There  is  no  movement  of  the  rib-heads  on  the  centra,  nor  of  these  on 
one  another. 

The  first  dorsal  vertebra  articulates  with  the  last  cervical,  permitting  a  very 
free  motion.  Its  ribs  are  short,  have  no  costal  plate,  and  lie  closely  joined  to  the 
front  of  the  rib  of  the  first  costal  plate.  From  this  it  will  be  seen  that  the  second 
rib  has  coalesct  with  the  first  costal  plate,  the  third  rib  with  the  second  costal,  and 
so  on.  The  tenth  dorsal  rib  is  short  and  slender;  its  distal  end  is  consolidated  with 
the  eighth  costal  plate,  and  has  the  upper  end  of  the  ilium  abutting  against  it. 

In  life  the  bones  of  the  carapace  and  the  plastron  are  covered  by  a  number  of 
horny  plates,  the  scutes.  Where  the  edges  of  any  two  of  these  meet  they  impress  a 
furrow  in  the  bone,  forming  a  sulcus.  When  the  skeleton  is  prepared  the  scutes 
fall  off,  but  the  sulci  remain  to  betray  the  number  and  form  of  the  scutes.  In  the 
figures  here  shown  (figs.  I,  2),  as  in  nearly  all  the  figures  of  this  work,  the  sulci  are 
represented  by  stippled  bands;  the  sutures  between  the  bones,  by  zigzag  Hnes. 
In  fig.  I  the  scutes  are  represented  on  both  sides  of  the  shell,  but  the  symbols  of 
the  names  are  placed  only  on  the  right  side.  Immediately  in  front,  at  the  midHne, 
there  is  a  small  scute,  the  nuchal  {nu.  s).  Then  comes  a  row  of  five  large  scutes, 
the  vertebrals  {y.  i,v.  2,  etc.),  each  extending  out  beyond  the  neural  bones.  The 
sulci  separating  these  scutes  cross  respectively  the  first,  third,  fifth,  and  eighth  neu- 
rals.  On  each  side  of  these  vertebrals  is  a  row  of  four  large  scutes,  the  costals  (c.  s, 
i;  c.  s,  2;  etc.).  The  sulci  between  these  descend  respectively  on  the  second, 
fourth,  sixth,  and  eighth  costal  bones. 

The  borders  of  the  carapace  are  invested  by  a  series  of  marginal  scutes,  twelve 
on  each  side  (i,  2,  3,  etc.,  on  right  side).  The  sulci  dividing  these  from  the  costal 
scutes  run  along  near  the  upper  border  of  the  peripheral  bones.  At  the  free  borders 
of  these  peripherals  the  scutes  turn  down  and  appear  on  the  under  sides  of  the 
bones. 

It  will  be  observed  that  the  scutes  coincide  neither  in  number  nor  position  with 
the  underlying  bones.  It  is  seldom  that  the  sulci  follow  the  sutures.  This  matter 
will  be  discust  hereafter. 

In  fig.  2  are  represented  the  plastral  scutes,  the  characters  indicating  the  names 
appearing  in  the  right  side  of  the  drawing.  A  median  longitudinal  sulcus  runs 
from  the  front  to  the  rear  of  the  plastron,  separating  the  scutes  of  each  pair.  In 
front  is  a  pair  of  gular  scutes  (g);  then  a  pair  of  humerals  {hum);  followed  by  the 
pectorals  {pec),  the  abdominals  {ab),  the  femorals  {fern),  and  finally,  by  the  anals 
{an).  Just  behind  each  axillary  notch  is  an  axillary  scute;  while  just  in  front  of 
each  inguinal  notch  is  found  an  inguinal  scute.  The  marginal  scutes  seen  in  this 
figure  are  the  same  that  appear  in  fig.   i. 

We  may  now  examine  the  vertebrae  in  front  of  and  behind  the  dorsals.  In  all 
of  the  turtles  there  are  normally  18  presacral  vertebrae,  of  which  8  belong  to  the 
neck.  The  more  anterior  and  the  more  posterior  cervicals  are  the  shorter.  The 
neck  as  a  whole  is  about  as  long  as  the  dorsal  series  of  vertebrae.  The  first  is  com- 
posite, consisting  of  four  distinct  pieces.  On  each  side  is  a  neural  arch,  aiding  in 
forming  the  neural  canal.  Below,  these  abut  on  a  median  piece,  the  hypocentrum. 
These  three  bones  unite  in  forming  a  concavity,  into  which  fits  the  ball-like  occipital 
condyle.  Behind  the  arches  and  the  hypocentrum  is  the  odontoid  process,  the  proper 
centrum  of  the  first  cervical.  Behind,  this  articulates  with  the  centrum  of  the 
second  cervical  but  does  not  become  anchylosed  with  it. 


OSTEOLOGY.  5 

Of  the  other  cervicals  the  arches  are  separable  from  the  centra  along  a  line  of 
cartilage.  The  neural  arches  are  all  low  and  devoid  of  spines.  There  are  no 
lateral  processes.  As  regards  the  articular  ends  of  the  centra,  there  is  great  diversity. 
In  Trachemys  scripta,  the  second  and  third  are  convexo-concave;  the  fourth  and 
the  eighth  are  convexo-convex;  the  fifth  is  concavo-convex;  and  the  seventh,  concavo- 
concave.  The  articulations  between  the  fifth  and  sixth,  the  sixth  and  the  seventh, 
and  the  seventh  and  the  eighth  are  extended  from  side  to  side  and  divided  medially, 
forming  a  true  hinge  joint,  which  permits  very  free  motion  up  and  down,  but 
restricts  it  from  side  to  side.  The  anterior  and  the  posterior  zygapophyses  are 
little  elevated  above  the  centra  and  are  placed  far  apart.  These  arrangements 
contribute  to  free  motion  in  a  perpendicular  plane,  but  limit  it  in  a  horizontal. 

Behind  the  last  dorsal  vertebra  come  two  sacrals.  Their  ribs  expand  distally 
and  articulate  with  the  upper  ends  of  the  iha.  The  sacrals  are  followed  by  a  number 
of  caudals,  about  15,  but  varying  with  the  species,  or  even  in  individuals.  Most 
of  these  have  transverse  processes. 

The  skull  of  Trachemys  scripta  seen  from  above  (fig.  3)  presents  three  pairs  of 
bones  which  join  at  the  median  line.  In  front  are  the  prefrontals,  extending  back- 
ward to  the  middle  of  the  orbits.  The  anterior  ends  roof  over  the  nasal  cavity. 
A  strong  process  descends  from  each  to  join  the  vomer  and  the  palatine,  and  to 
form  the  front  wall  of  the  orbit.  Behind  the  prefrontals  are  placed  the  larger 
jrontals.  They  aid  in  forming  the  rim  of  the  orbits.  The  parietals  are  important 
bones,  inasmuch  as  they  form  the  roof  and  much  of  the  lateral  walls  of  the  brain- 
case.  The  anterior  end  of  each  sends  downward  a  strong  process  which  joins  the 
pterygoid.  Besides  the  pterygoid,  the  lower  border  of  the  parietal  articulates  with 
the  prootic  and  the  supraoccipital.  The  latter  bone  is  greatly  prolonged  backward, 
as  it  is  in  almost  all  turtles.  It  forms  a  small  part  of  the  boundary  of  the  foramen 
magnum. 

The  maxilla  bounds  the  nasal  cavity  on  the  side,  the  orbit  below,  and  its  lower 
border  forms  an  acute  cutting-edge.  In  life  this  edge  is  covered  with  a  horny 
sheath.  Posteriorly  the  maxilla  articulates  with  the  jugal.  The  hinder  part  of  the 
rim  of  the  orbit  is  formed  of  the  jugal  below  and  of  the  postfrontal  above.  These 
two  bones  form  a  postorbital  bar  of  moderate  width. 

A  large  tympanic  cavity  is  excavated  in  the  quadrate,  an  extremely  important 
bone  among  the  reptiles.  Below  the  cavity  mentioned,  the  quadrate  descends  to 
form  a  movable  articulation  with  the  lower  jaw.  In  the  hinder  border  of  the  quad- 
rate is  a  small,  but  deep  notch  for  the  passage  of  a  long,  rod-like  bone,  the  columella. 
Interposed  between  the  anterior  border  of  the  quadrate  and  the  jugal  bone  is  the 
quadrato jugal.  The  jugal  and  quadratojugal  form  the  zygomatic  arch.  Above 
and  behind  the  quadrate  is  the  squamosal. 

The  sides  of  the  hinder  part  of  the  skull  are  occupied  each  by  a  long  excavation, 
the  temporal  fossa.  The  floor  of  this  is  formed  of  the  parietal  on  the  inside,  of  the 
prootic  and  paroccipital  in  the  middle,  and  of  the  quadrate  and  squamosal  on  the 
outside. 

Fig.  4  represents  the  skull  of  the  same  species  as  seen  from  below.  In  front  are 
the  premaxillce,  bounding  the  nasal  cavity  below  and  entering  into  the  roof  of  the 
mouth.  On  each  side  and  behind  the  premaxilla  is  the  maxilla.  It  presents  out- 
wardly the  cutting-edge  already  mentioned.  Its  inner  border  joins,  in  front,  the 
vomer,  posteriorly  the  palatine;  the  middle  portion  is  mostly  a  free  edge,  forming 
the  lateral  boundary  of  the  choana.  Between  the  two  borders  is  a  broad  triturating, 
or  alveolar,  surface,  which  in  life  is  covered  with  a  horny  sheath.  Along  the  middle 
of  this,  parallel  with  the  cutting-edge,  is  a  sharp  ridge,  slightly  tootht. 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


The  midline  behind  the  premaxillje  is  occupied  by  the  single  vomer.  Anteriorly 
it  divides  the  nasal  passages  from  each  other;  laterally  it  articulates  with  the 
palatines;  posteriorly,  with  the  pterygoids.  The  palatines  assist  in  roofing  the 
nasal  passages  and  in  forming  the  triturating  surface  mentioned.  Between  each 
and  the  maxilla  of  its  side  is  seen  an  opening,  the  posterior  palatine  foramen. 

The  pterygoids  meet  each  other  at  the  midline  anteriorly,  but  posteriorly  are 
separated  by  the  basisphenoid.  They  extend  backward  so  far  as  to  exclude  the 
bone  last  mentioned  from  contact  with  the  quadrates.  The  lateral  border  of  each 
pterygoid  is  mostly  a  sharp  free  edge.  Behind  the  basisphenoid  comes  the  hasiocctpi- 
tal.  It  is  joined  on  each  side  by  the  exoccipital,  and  all  three  of  these  bones  join  in 
forming  the  occipital  condyle.  From  this  view  is  seen  also  a  portion  of  the  par- 
occipital  and  squamosal.  On  each  side  of  the  basicranial  axis  are  seen  foramina 
for  the  passage  of  various  nerves  and  blood-vessels. 

Each  ramus  of  the  lower  jaw  is  composed  of  six  bones.  In  front  is  the  dentary, 
furnishing  the  triturating  surface  of  the  jaw,  covered  above  with  a  horny  sheath,  and 


■pnuc 


Figs.  3"andj4.     Trachemyfscripta. 

3.  Skull  seen  from  above.     Xi.  /r,  frontal;  _/u,  jugal;  /iii,  parietal;  /)aoc,  paroccipital;  />/r,  prefrontal;  ^0/,  post- 

frontal;  pro,  prootic;  j«,  quadrate;  jy,  squamosal;  50c,  supraoccipital. 

4.  Skull  seen  from  below.    Xi.    a/r,  alveolar  surface  of  maxilla;  6of,  basioccipital;  ^jp,  basisphenoid;  «.voc,  exoc- 

cipital;  mXy  maxilla;  paly  palatine;  paoCy  paroccipital;  pmx,  premaxilla;  pro^  prootic;  pty  pterygoid;   jw.  art, 
articulation  of  quadrate  with  lower  jaw;  gy,  quadratojugal;  55,  squamosal;  voniy  vomer. 

completely  co-ossified  with  its  fellow  of  the  opposite  side  at  the  symphysis.  On  the 
lower  border  of  the  jaw  this  bone  extends  backward  nearly  to  the  articulation  with 
the  quadrate.  The  upper  border  of  the  jaw,  behind  the  triturating  surface,  is  formed 
in  front  by  the  coronoid  bone;  posteriorly  by  the  supraangular.  These  two  bones 
are  to  be  seen  both  from  the  outside  and  from  the  inside  of  the  jaw.  Behind  the 
supraangular  is  a  nodular  bone  that  articulates  with  the  quadrate,  the  articular. 
On  the  inner  surface  of  the  jaw,  near  the  hinder  end,  are  two  bones,  whose  names 
are  in  dispute.  Baur  (Anatomischer  Anzeiger,  xi,  1896,  p.  413)  calls  the  lower  of 
the  two  the  splenial,  the  upper  the  angular.  Williston  (Science,  xviii,  1903,  p.  830) 
regards  the  lower  bone  as  the  angular,  the  upper  as  a  dermal  articular.  The  same 
author  has,  in  his  work  on  North  American  Plesiosaurs,  1903,  page  30,  called  the 
latter  bone  the  prearticular,  and  this  name  is  adopted  by  the  present  writer. 

The  shoulder-girdle  of  an  emyd  turtle  consists  of  two  bones  on  each  side.  One 
of  these,  the  scapula,  consists  of  two  slender  portions  placed  at  nearly  a  right  angle 
with  each  other.    The  longest  portion,  the  proper  scapula,  the  body  of  the  scapula, 


OSTEOLOGY.  7 

extends  from  the  glenoid  cavity,  of  which  it  furnishes  more  than  half,  upward  and 
inward,  to  become  ligamentously  attacht  to  the  upper  end  of  the  first  costal  plate. 
The  other  part  of  this  bone  extends  from  above  the  glenoid  cavity  inward  and 
forward,  to  be  attacht  by  ligament  to  the  entoplastron.  This  process  has  been 
variously  interpreted,  but  here  it  is  regarded  as  the  procoracoid,  which  has  become 
co-ossified  with  the  scapula.  It  will  be  called  the  procoracoid  process.  For  a  dis- 
cussion of  this  subject  and  a  list  of  writers  who  have  considered  it  the  reader  is 
referred  to  a  paper  by  Max  Fiirbringer  in  Jenaische  Zeitschrift,  xxxiv,  1900. 
The  other  bone  of  the  girdle  is  the  coracoid.  It  starts  from  the  glenoid  cavity, 
and  proceeds  inward  and  slightly  backward,  to  approach  closely  its  fellow  at  the 
midline. 

The  writer  regards  the  chelonian  limb  as  belonging  to  a  relatively  primitive 
type.  If  the  reader  will  peruse  Huxley's  chapter  on  the  position  of  the  limbs,  in 
his  Anatomy  of  Vertebrated  Animals  (Appleton's  edition,  1872,  p.  33),  and  com- 
pare his  statements  with  what  he  can  see  in  the  limbs  of  a  turtle,  he  will  probably 
agree  with  the  view  here  presented.  The  apex  of  the  angle  at  the  elbow,  instead  of 
being  directed  backward,  is  rather  directed  forward  and  upward.  There  is  no 
crossing  of  the  ulna  and  radius. 

The  humerus  of  the  emyd  is  rather  strongly  bent  in  the  plane  passing  through 
the  axes  of  the  three  segments  of  the  Hmb.  The  head  is  directed  upward.  The 
strongly  developt  tuberosities  for  attachment  of  muscles,  the  radial,  or  lateral,  and 
the  ulnar,  or  medial,  are  bent  toward  the  lower  face  of  the  bone.  The  ulnar  is 
always  the  larger.  At  the  distal  end  of  the  bone,  on  the  anterior  or  radial  side,  is  a 
passage  for  the  radial  nerve,  the  ectepicondylar  foramen. 

Of  the  two  bones  of  the  lower  arm  the  radius  is  the  smaller.  It  has  a  shallow 
cavity  at  the  proximal  end  that  meets  the  articular  end  of  the  humerus.  Its  distal 
end  is  expanded  and  articulates  with  the  intermedium  and  the  radiocentrale  of  the 
carpus.  The  ulna  is  the  stouter  bone,  is  flattened,  has  the  suggestion  of  an  olecranon 
process,  and  articulates  distally  with  the  intermedium  and  the  ulnare. 

The  carpus  is  simple.  Besides  the  bones  already  mentioned  as  belonging  to  the 
carpus,  there  is  another  in  the  proximal  row,  on  the  outer  side  of  the  ulna.  There 
are  5  bones  in  the  distal  row,  but  sometimes  the  fourth  and  the  fifth  are  co-ossified. 
There  are  5  metacarpals,  each  of  medium  length.  The  digits  are  5  in  number,  the 
first  and  the  fifth  the  shortest.  The  first  digit  has  2  phalanges,  the  others  3  each, 
exactly  as  in  the  Mammalia. 

The  pelvis  is  broad  and  short,  and  each  half  is  composed  of  3  bones,  all  of 
which  take  part  in  the  formation  of  the  acetabulum.  The  ilium  is  expanded  antero- 
posteriorly  above  and  is  articulated  with  the  outer  ends  of  the  sacral  ribs.  The 
middle  of  the  bone  is  slender.  Each  ischium  has  a  posterior  process  which  rests 
on  the  xiphiplastron  and  an  anterior  process  which  runs  forward  to  join  the  pubis 
of  its  side.  There  is  thus  produced  on  each  side  a  large  heart-shaped  fontanel, 
the  ischio-pubic  foramen.  Each  pubis  has  a  lateral  process  which  rests  on  the 
xiphiplastron.  The  pubis  is  prolonged  forward  considerably,  and  between  the  two 
there  is  a  median  notch  which  in  life  is  filled  with  cartilage,  the  prepubic;  but  this 
does  not  become  ossified. 

The  femur  resembles  considerably  the  humerus;  but  it  is  a  longer  bone  and 
there  is  no  perforation  corresponding  to  the  ectepicondylar  foramen.  The  head  is 
larger  and  of  different  form.  The  trochanters  are  of  about  the  same  size  and  the 
digital  fossa  separates  them  far  down.  The  tihia  is  a  stouter  bone  than  the  fibula. 
Its  upper  end  is  the  larger  and  presents  a  large  surface  for  articulation  with  the  femur. 
The  lower  end  has  a  saddle-shaped  articular  surface  to  join  the  large  bone  forming 


8  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

the  first  row  of  the  tarsus.  The  fibula  is  slender,  with  the  broader  end  downward, 
articulating  with  l^he  same  bone  as  does  the  tibia.  The  bone  of  the  tarsus  just 
mentioned  is  the  only  one  present  in  the  upper  row,  and  is  regarded  as  representing 
three  bones  that  theoretically  belong  in  the  upper  row,  besides  the  centrale.  In  the 
lower  row  of  tarsal  bones  there  are  five  present,  all  articulating  above  with  the 
large  bone  of  the  upper  row  and  distally  each  with  one  of  the  metatarsals.  The 
fifth  of  these  bones  is  peculiarly  expanded  in  the  turtles. 

The  5  metatarsals  are  rather  elongated  in  Graptemys  and  Trachemys,  as  are, 
too,  the  phalanges.  In  the  first  digit  there  are  2  phalanges;  in  each  of  the  others,  3. 
All  the  terminal  phalanges  are  invested  in  horny  claws,  except  the  fifth. 

THE  CHELONIID/E.    THE  SEA-TURTLES. 

Some  of  the  salient  features  of  the  Cheloniidae  will  now  be  described.  These 
constitute  a  family  of  the  Cryptodira,  a  superfamily  to  which  also  the  Emydidae 
belong.  The  Cheloniidae  are  greatly  different  in  some  respects  from  the  Emydidae. 
The  shell  is  composed  of  the  same  elements,  but  many  are  less  completely  developt. 
In  general,  the  border  of  the  carapace  is  excavated  in  front  for  the  neck;  and  on 
each  side  of  this  for  free  movement  of  the  fore  limbs.  Behind,  it  is  pointed,  so 
that  in  form  the  carapace  is  somewhat  heart-shaped.  The  costal  plates  fall  short 
of  reaching  the  distal  ends  of  the  ribs,  as  a  result  of  which  open  spaces,  or  fontanels, 
are  left  between  the  costals  and  the  peripherals.  Usually  none  of  the  costal  plates 
come  into  contact  with  the  peripherals.  The  ribs  of  the  costals,  however,  reach 
these  bones  and  each  enters  a  pit  in  a  corresponding  peripheral.  In  the  loggerhead 
(Caretta  caretta),  for  example,  rib-ends  enter  peripherals  3  to  8  inclusive  and 
peripherals  10  and  11.  In  some  forms,  as  Lepidochelys,  there  are  supernumerary 
bones  interposed  among  the  neurals,  so  that  the  number  of  these  seems  to  be  as 
high  as  14. 

The  carapace  is  furnisht  with  scutes  similar  to  those  of  the  Emydidae.  In 
Caretta  and  Lepidochelys  there  is  a  supernumerary  costal  scute  in  front  of  the 
normal  first. 

Altho  the  plastron  of  these  turtles  is  composed  of  the  same  elements  as  that  of 
the  Emydidae,  some  of  these  are  greatly  modified.  The  hyoplastra  and  the  hypoplas- 
tra  are  not  suturally  connected  with  the  peripherals  of  the  bridge;  nor  do  the 
plastral  bones  just  named  come  into  contact  with  their  fellows  at  the  midline,  so 
that  the  space  between  the  bones  of  the  right  and  of  the  left  sides  is  occupied  by  a 
great  fontanel.  On  each  side  there  is  another  fontanel  inclosed  by  the  bridge 
peripherals,  the  outer  end  of  the  hyoplastron,  and  that  of  the  hypoplastron.  The 
inner  and  the  outer  borders  of  the  two  sets  of  bones  last  mentioned  send  out  a 
number  of  digitations  into  the  fontanels.  The  epiplastra  are  saber-shaped  bones 
which  join  each  other  and  the  entoplastron  at  the  midhne,  without  jagged  sutures; 
and  their  distal  ends  are  applied  to  the  outer  border  of  the  corresponding  hyo- 
plastrals.  The  xiphiplastra  are  narrow,  curved  bones  that  approach  each  other 
at  their  distal  ends. 

Carapaces  and  plastra  similar  to  those  of  the  Cheloniidae  are  found  among  the 
Thalassemydidas,  and  to  these  the  reader  is  referred  for  illustrations. 

The  neck  of  the  Cheloniidae  is  much  shorter  than  that  of  the  Emydidae  and  the 
head  can  hardly  be  retracted  within  the  shell.  In  the  loggerhead  the  neck  is  but 
little  more  than  half  as  long  as  the  series  of  dorsal  vertebrae.  The  eighth  cervical 
articulates  by  a  synovial  surface  with  the  inferior  side  of  the  nuchal  bone.  The 
series  of  caudal  vertebrae  is  short. 


OSTEOLOGY.  9 

The  skull  of  the  Cheloniidae  differs  in  some  important  respects  from  that  of  the 
Emydidae.  In  order  to  illustrate  this,  figures  are  here  introduced  giving  upper 
(plate  I,  fig.  i),  lower  (plate  i,  fig.  2),  and  lateral  (plate  2,  fig.  i)  views  of  the  skull 
oi  Leptdochelys  kempt  Garman.  These  figures  were  prepared  for  Dr.  George  Baur, 
in  1888,  but  reverted  to  the  United  States  Geological  Survey,  the  then  director  of 
which,  Dr.  C.  D.  Walcott,  has  permitted  them  to  be  used  here.  No  figures  of 
this  species  have  hitherto  been  pubUsht.  The  most  interesting  feature  of  the 
skulls  of  the  sea-turtles  is  the  great  extent  of  the  bony  roof  covering  the  temporal 
region.  This  roof  extends  from  the  orbit  to  behind  the  plane  of  the  occipital  con- 
dyle. The  postfrontal  bone,  narrow  in  the  emyds,  is  carried  backward  nearly  to 
the  hinder  border  of  the  roof.  The  squamosal  sends  upward  and  inward  a  plate 
that  meets  a  horizontal  plate  from  the  parietal,  forming  a  parieto-squamosal  arch. 

1  he  lower  side  of  the  skull  is  interesting 
chiefly  because  of  the  broadening  of  the  triturat- 
ing surfaces  of  the  jaws.  The  palatal  plates  of 
the  vomer  extend  backward  until  they  meet 
similar  plates  from  the  palatines.  The  choanae 
are  thus  thrown  much  farther  toward  the  middle 
of  the  skull  than  in  the  skull  represented  by  text- 
figure  4.  The  crushing  surfaces  of  the  lower 
jaw  are  correspondingly  widened  (plate  I,  figs. 
3  and  4).    In  the  Thalassemydidae  the  choanae 

Fig.   s.-Care^tta^caretta.     Pelvis  from      ^^^  ^^  ^^^^^   ^^^^   ^^^^^^^   backward,   aS   may 

be  seen  by  examining  the  skull  of  Rhetechelys 
platyops  (Cope).    There  are  no  posterior  palatine  foramina. 

In  the  Cheloniidae  the  procoracoid  process  makes  an  obtuse  angle  with  the  body 
of  the  scapula,  and  there  is  a  distinct  neck  between  the  process  and  the  glenoid 
fossa.  The  coracoid  bone  is  longer  than  the  scapula  and  moderately  expanded  at 
its  free  end.    These  bones  are  represented  by  fig.  2  of  plate  2. 

The  humerus  of  these  sea-turtles  is  strongly  modified  from  the  primitive  form. 
It  is  much  straighter  than  that  of  the  Emydidae  and  has  become  flattened  in  the 
plane  of  the  distal  end.  The  head  and  the  radial  and  ulnar  tuberosities  have  changed 
positions.  The  head  is  turned  downward  and  proximad  into  the  plane  of  the  bone, 
while  the  tuberosities  are  lifted  into  this  plane,  each  on  its  proper  border  of  the  bone. 
The  radial  tuberosity  is  carried  along  on  the  shaft  of  the  bone  until  it  has  lost  its 
connection  with  the  head.  It  becomes  divided  into  two  parts,  one  for  the  deltoid 
muscle,  the  other  for  the  supracoracoid.  Fig.  3,  plate  2,  represents  the  humerus  of 
Lepidochelys  as  seen  from  above;   fig.  4,  as  seen  from  below. 

Relatively  to  the  humerus,  the  radius  and  the  ulna  are  shortened,  the  ulna 
more  than  the  radius.  In  the  carpus  the  radiale  remains  small,  the  intermedium 
and  the  ulnare  are  enlarged  and  flattened,  while  the  centrale  is  distinct.  There  are 
five  bones  in  the  distal  row,  one  articulating  with  each  metacarpal.  The  third  and 
the  fourth  may  be  co-ossified.  On  the  ulnar  side  of  the  carpus  there  is  a  large  flat 
bone  assisting  to  broaden  the  carpus.    It  may  be  regarded  as  the  pisiform. 

The  second,  third,  and  fourth  digits  are  greatly  elongated,  the  bones  flat- 
tened, and  all  are  bound  together  in  a  mass  of  muscles  and  skin  to  form  an  undivided 
oar.    The  first,  and  in  some  cases  the  second,  digit  is  provided  with  a  claw. 

The  pelvis  of  the  Cheloniidae  is  broad  and  deprest  (fig.  5).  The  ilia  are  short; 
the  upper  end  is  slender  and  turned  backward  and  the  axis  of  the  bone  is  nearly 
in  the  plane  of  the  pubes.    The  latter  bones  are  broad.     Between  the  two,  at  the 


10  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

midline  in  front,  there  is  a  deep  notch,  filled  in  life  by  the  prepubic  cartilage.  The 
lateral  processes  are  broad.  The  ischia  are  without  posterior  lateral  processes,  and 
they  are  not  connected  with  the  pubes  on  the  midline  by  bone;  thus  the  ischio- 
pubic  foramina  unite  into  one  in  the  prepared  skeleton. 

The  femur,  which  in  the  emyds  is  longer  than  the  humerus,  is,  in  the  sea-turtles, 
shorter  than  the  latter  element.  The  shaft  is  not  so  straight  as  is  that  of  the  humerus 
and  the  head  is  not  so  much  deflected  toward  the  axis  of  the  shaft.  The  trochanters 
differ  considerably  in  size  and  the  digital  fossa  does  not  descend  far  between  them. 
The  tibia  and  the  fibula  are  relatively  stout  bones.  While  in  the  emyds  described 
above,  the  two  upper  segments  of  the  fore  limb  are  considerably  shorter  than  the 
corresponding  segments  of  the  hinder,  the  reverse  is  true  in  the  Cheloniidae.  Figs. 
5  and  6  of  plate  2  represent  the  femur  of  Lepidochelys. 

The  hinder  foot  of  sea-turtles  is,  compared  with  the  fore  foot,  greatly  reduced. 
In  Caretta  the  hinder  foot,  including  the  tarsus,  is  only  about  half  as  long  as  the 
fore  foot.     There  are  2  bones  in  the  first  row  of  the  tarsus,  5  in  the  second  row. 

THE  TRIONYCHOIDEA.    THE  SOFT-SHELLED  TURTLES. 

We  will  give  our  attention  now  to  members  of  another  superfamily,  the  Tri- 
onychoidea,  popularly  known  as  soft-shelled  turtles,  sometimes  as  mud-turtles,  or 
river  turtles.  The  two  last-mentioned  names  are,  however,  often  applied  to  other 
groups  of  turtles. 

In  these,  as  in  other  turtles,  there  is  a  carapace  and  a  plastron;  but  they  differ 
greatly  in  appearance  from  those  of  the  emyds.  The  whole  body  is  greatly  deprest. 
For  illustrations  of  these  portions  of  the  shell  the  reader  may  consult  the  figures  of 
the  fossil  species  on  succeeding  pages.  The  carapace  is  usually  composed  of  neurals, 
7  or  8  in  number,  7  or  8  pairs  of  costals,  and  a  nuchal  bone.  Only  in  one  genus, 
Trionyx  (EmyJa  Gray),  including  two  Asiatic  species,  are  there  any  suggestions  of 
peripherals.  The  costal  bones  are  closely  articulated  to  their  neighbors  and  the 
contiguous  neurals;  but  often  these  costals  do  not  extend  to  the  ends  of  the  ribs; 
or,  if  they  do,  it  is  only  in  very  advanced  age.  In  Hfe  the  periphery  of  the  shell  is 
surrounded  by  a  rim  of  dense  and  flexible  connective  tissue,  terminating  all  round 
in  a  sharp  edge.    It  is  this  rim  that  has  suggested  the  name  soft-shell. 

The  whole  upper  surface  of  the  carapace  is  ornamented  with  a  network  of 
ridges  which  inclose  pits  of  various  forms.  The  size  and  arrangement  of  the  ridges 
and  pits  vary  in  the  different  species.  There  are  never  any  traces  of  horny  scutes, 
the  outer  skin  always  remaining  soft. 

The  plastron  in  some  respects  resembles  that  of  the  sea-turtles,  inasmuch  as 
there  are  median  and  lateral  fontanels  and  the  connection  with  the  carapace  is 
a  ligamentous  one.  The  hyoplastra  and  the  hypoplastra  are  furnisht  with  median 
and  lateral  digitations.  Of  the  median  digitations  one  belongs  to  each  hyoplastron 
and  is  directed  forward  and  inward,  to  come  into  contact  with  the  entoplastron. 
Two  belong  to  each  hypoplastron,  one  being  directed  toward  that  of  the  opposite 
side,  the  other  toward  the  xiphiplastron.  Of  the  lateral  digitations  one  set  is 
directed  from  each  hyoplastron  forward  and  outward,  the  other  from  the  hypo- 
plastron backward  and  outward.  The  hyoplastron  and  the  hypoplastron  of  each 
side  are  closely  sutured  together,  in  some  cases  co-ossified. 

The  entoplastron  is  V-shaped,  the  apex  being  directed  forward,  an  arm  resting 
against  the  hyoplastron  of  each  side.  The  epiplastral  bones  are  slender  and  curved, 
usually  not  in  contact  with  each  other  at  the  midhne.  They  differ  from  these 
bones  in  all  other  turtles  in  being  excluded  from  contact  with  the  hyoplastra  by 
the  arms  of  the  entoplastron. 


OSTEOLOGY.  I I 

The  xiphiplastra  are  usually  more  or  less  curved  bones,  whose  anterior  ends 
interdigitate  with  the  hypoplastra,  while  their  posterior  ends  meet  at  the  midhne. 

In  some  cases  the  plastral  bones  are  smooth  and  devoid  of  ornamentation.  In 
many  other  cases  there  are  developt  on  their  lower  surfaces  patches  of  more  super- 
ficial bone,  the  callosities.  These  callosities  are  sculptured  into  pits  and  ridges, 
somewhat  like  the  bones  of  the  carapace,  but  the  pattern  may  be  different.  Each 
callosity  may  occupy  but  a  small  part  of  the  bone  developing  it  or  it  may  extend 
over  the  whole  bone.  The  callosities  are  more  extensive  in  the  Cretaceous  and 
Tertiary  species  than  in  those  now  existing. 

The  best  description  of  the  plastral  bones  of  living  Trionychidae  has  been 
publisht  by  Dr.  Friedrich  Siebenrock  (Sitzungsber.  Akad.  Wiss.  Wien,  cxi,  1902, 
pp.  807-846). 

In  the  Plastomenidae  the  median  fontanels  are  filled  up;  and  the  whole  lower 
surface  of  the  hyoplastra,  hypoplastra,  and  the  xiphiplastra  is  sculptured. 

The  neck  of  the  soft-shelled  turtles  is  long  and  slender,  and,  hke  that  of  the 
Cryptodira,  it  bends  most  freely  in  a  perpendicular  plane.  In  a  specimen  of  Platy- 
peltis  spinifera  at  hand  all  the  centra  are  convex  in  front,  concave  behind,  except 
that  the  hinder  end  of  the  eighth  is  reduced  to  a  thin  edge.  This  cervical  is  con- 
nected with  the  first  dorsal  almost  wholly  by  the  zygapophyses. 

The  skull  of  the  soft-shelled  turtles  presents  many  distinctive  features.  Fig. 
I,  plate  3,  represents  that  oi  Platypeltis  ferox,  a  Florida  species,  seen  from  above; 
fig.  2,  plate  3,  the  same  skull  as  seen  from  below.  The  skull  is  elongated  and  pointed 
in  front.  The  posterior  region  is  notable  for  the  three  large  backwardly  directed 
processes,  the  supraoccipital  and  the  two  squamosal  processes.  Of  the  temporal 
roof  there  is  no  part  except  the  postorbital  and  the  zygomatic  bars.  The  prootic 
extends  much  in  front  of  the  articulation  of  the  lower  jaw.  The  hinder  border  of 
the  pedicel  of  the  quadrate  is  closed  behind  the  stapes,  so  that  this  occupies  a  canal, 
instead  of  a  notch.  The  premaxillae  have  coalesct  into  a  single  small  bone.  Seen 
from  below,  the  skull  presents  in  front  a  median  prepalatine  foramen  and  the  two 
choanae.  Altho  the  latter  open  rather  far  backward,  they  are  not  underfloored  by 
vomerine,  palatine,  and  maxillary  plates.  The  triturating  surfaces  of  this  species 
are  rather  broad.  The  vomer  is  always  small.  The  palatines  meet  throughout 
their  length  at  the  midline,  and  posteriorly  they  articulate  with  the  basisphenoid. 
The  pterygoids  are  broad,  run  backward  alongside  the  basioccipital,  and  do  not 
meet  on  the  median  line.  The  basioccipital  and  the  exoccipitals  all  take  part  in 
the  occipital  condyle.     The  paroccipital  is  a  large  bone. 

The  lower  jaw  (plate  i,  fig.  5)  is  composed  of  the  same  elements  as  that  of  the 
emyds.  The  coronoid  bone  is  large  and  the  angle  of  the  jaw  projects  considerably 
behind  the  articulation  with  the  quadrate. 

The  hyoid  apparatus  is  strongly  developt. 

In  order  to  accommodate  itself  to  the  flattened  form  of  the  body,  the  scapula  is 
directed  from  the  glenoid  fossa  upward,  forward,  and  inward,  making  an  angle  of 
about  50  degrees  with  the  procoracoid  process  (plate  3,  fig.  3).  The  latter  is  slightly 
expanded  toward  its  distal  end  and  flattened.  The  coracoid  is  broad  and  flat  and 
somewhat  saber-shaped. 

The  humerus  (plate  3,  figs.  4,  5)  is  a  stouter  bone  than  that  of  the  emyds  above 
described,  and  it  is  less  neatly  modeled.  The  proximal  tuberosities,  the  radial  and 
the  ulnar,  are  larger,  with  a  broader  fossa  between  them.  The  ectepicondylar  passage 
is  a  groove.    The  radius  is  half  the  length  of  the  humerus;  the  ulna  is  still  shorter. 

The  fore  foot  is  as  long  as  the  humerus,  a  condition  due  to  the  elongation  of 
especially  the  median  digits.    The  three  on  the  radial  side  have  claws,  the  others 


12  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

do  not.  The  phalangeal  formula  of  the  first  three  digits  is  2,  3,  3,  as  in  Emydidae. 
The  fourth  may  have  4,  5,  or  6,  while  the  fifth  finger  may  have  3  or  4  phalanges. 

The  pelvis  resembles  much  that  of  the  Cheloniidae,  but  the  opening  representing 
the  united  ischio-pubic  foramina  is  larger.  The  ilium  is  short  and  slender  and 
the  upper  end  is  turned  backward.     The  ischia  have  short  posterior  processes. 

The  femur  (plate  3,  figs.  6,  7)  is  slightly  longer  than  the  humerus,  which  it 
resembles  considerably.  It  may  be  distinguisht  by  its  having  no  ectepicondylar 
groove  and  by  the  narrower,  more  elongated,  head.  The  trochanters  are  wide 
apart  and  wholly  separated  by  the  interdigital  fossa. 

The  tibia  is  a  stout  bone  nearly  three-fourths  as  long  as  the  femur.  As  in  other 
turtles,  the  tibia  is  a  slenderer  bone.  The  hinder  foot  is  still  more  elongated  than 
the  anterior,  that  of  P.  spinifera  being  more  than  a  third  longer  than  the  femur. 
The  first  three  digits  have  the  same  number  of  phalanges  as  other  turtles;  that  is 
2,  3,  3.  The  fourth  digit  may  have  4  or  5  phalanges;  the  fifth,  2  or  3.  The  first 
three  have  claws. 

THE  PLEURODIRA.     THE  SNAKE-NECKT,  OR  SIDE-NECKT  TURTLES. 

It  is  necessary  to  make  some  observations  on  the  osteology  of  the  members  of 
another  superfamily,  the  Pleurodira.  The  shell  is  composed  of  the  same  elements 
as  in  the  emyds  and  often  presents  no  important  differences  from  that  of  the  latter. 
There  are  genera  in  which  the  neurals  are  reduced  in  number  and  a  few  in  which 
these  bones  have  been  wholly  supprest.  In  a  few  living  genera  and  in  some 
that  are  extinct  there  is  present  a  pair  of  bones,  unknown  in  the  Cryptodira  and 
Trionychoidea,  the  mesoplastrals,  interposed  between  the  hyoplastrals  and  the 
hypoplastrals.  In  Pelustos  (Sternothcerus)  these  bones  join  across  the  plastron. 
In  Pelomedusa  they  are  small  triangular  bones  occupying  the  middle  of  the  bridge 
only.  The  same  bones  occur  in  the  species  of  Ba'ena;  and  the  reader  may  consult 
the  figures  under  that  genus. 

The  shell  of  all  Pleurodira  differs  from  that  of  other  turtles  in  forming  sutural 
connections  with  the  pelvis.  The  eighth  costal  plates  develop  each  a  sutural  surface 
for  the  upper  end  of  the  ilium.  On  each  of  the  xiphiplastrals  are  two  sutural  scars, 
the  anterior  for  union  with  the  pubis,  the  posterior  for  union  with  the  ischium. 
On  other  pages  will  be  found  figures  of  the  species  of  Taphrosphys,  which  represent 
these  articulations.  In  the  Pleurodira  there  is  probably  always  an  intergular  scute 
present.    Sometimes  the  gulars  meet  in  front  of  it. 

The  cervical  vertebrae  are,  as  in  all  turtles,  8  in  number,  but  they  differ  greatly 
from  those  of  the  Cryptodira  and  of  the  Trionychoidea.  In  contradistinction  to  the 
neck  of  the  latter  turtles,  that  of  the  Pleurodira  is  constructed  for  free  flexure  in  a 
horizontal  plane.  This  is  effected  by  having  the  centra  joined  by  ball-and-socket 
joints  and  by  having  the  zygapophyses  of  the  two  sides  placed  close  together  and 
high  above  the  centra.  A  description  of  these  vertebrae  is  given  from  the  neck  of 
Hydromedusa  tectifera. 

The  neck  is  nearly  a  third  longer  than  the  dorsal  series  of  vertebrae.  The  first 
cervical,  unlike  that  of  the  other  superfamilies,  has  all  the  elements  consoHdated 
and  is  two-thirds  as  long  as  the  longest.  As  regards  the  articular  ends  of  the  centra 
we  have  the  following:  The  first  and  the  seventh  are  concavo-concave;  the  second, 
third,  and  fourth  are  convexo-concave;  the  fifth  and  the  eighth  are  convexo-convex; 
the  sixth  is  concavo-convex.  All  the  cervicals  possess  well-developt  transverse 
processes,  with  broad  bases.  Along  the  lower  side  of  the  centrum  of  each  runs 
a  sharp  crest.     The  postzygapophyses  of  the  first  two  vertebrae  are  separated  by 


OSTEOLOGY. 


^3 


only  a  slight  notch;  all  the  others  have  coalesct.  The  prezygapophyses  are  close 
together,  but  have  not  coalesct.  Those  of  the  eighth  are  very  small,  thus  greatly 
different  from  those  of  the  members  of  the  other  superfamilies. 

In  some  of  the  other  Pleurodira  the  intercentrum  and  the  odontoid  process  of 
the  first  cervical  are  distinct  from  the  arches.  In  the  Pelomedusidae  only  the  second 
cervical  is  convexo-convex;  all  the  others  concavo-convex. 

In  none  of  the  Pleurodira  is  the  neck  withdrawn  into  the  shell  as  it  is  in  the  other 
turtles,  but  is  bent  sideways  and  brought  under  the  projecting  borders  of  the  shell. 
In  harmony  with  this  action,  the  anterior  bones  of  the  carapace  and  of  the  plastron 
often  project  farther  than  in  other  turtles. 

The  skull  of  the  Pleurodires  offers  many  peculiar  structures.  That  of  Hydrome- 
dusa  may  first  be  considered.  This  skull  is  long  and  very  flat.  There  are  distinct 
nasal  bones.  The  prefrontals  do  not  send  down  processes  to  the  vomer.  There  is  a 
postorbital  arch,  but  no  zygomatic  arch.  At  the  rear  there  is  a  very  slender  palato- 
squamosal  arch.  Seen  from  above  the  whole  upper  surface  of  the  pterygoids  and  the 
whole  temporal  fossae  are  exposed  to  view.  There  is  no  ridge  projecting  outward 
from  the  parietal  over  what  may  be  called  the  suprapterygoid  fossa,  as  in  other 
turtles;  nor  does  the  prootic  project  forward  over  this  fossa.  The  fossa  just  men- 
tioned is  bounded  outwardly  by  the  upturned  outer  border  of  the  broad  pterygoids. 
The  premaxillas  are  small.    The  supraoccipital  spine  is  extremely  short. 

Fig.  6  represents  the  skull  seen  from  below.  The 
triturating  surfaces  of  the  upper  jaw  are  very  narrow. 
The  choanal  openings  are  very  large  and  are  separated 
by  the  splint-like  vomer,  which  comes  into  contact  with 
the  pterygoids.  The  latter  bones  separate  widely  the 
small  palatines.  Behind  the  latter  bones  are  the  posterior 
palatine  foramina.  The  pterygoids  are  greatly  developt 
anteriorly  and  laterally.  They  are  in  contact  on  the  mid- 
line in  front,  but  for  more  than  half  their  length  the 
basisphenoid  bone  comes  between  them.  The  pterygoids 
are  abbreviated  behind,  so  that  they  permit  the  quadrates 
to  join  the  basisphenoid.  This  arrangement  is  character- 
istic of  the  Pleurodires  and  distinguishes  them  from  all 
other  turtles.  The  quadrate  is  notcht  behind  for  the 
passage  of  the  stapes. 

The  lower  jaw  is  slender  and  the  coronoid  processes 
are  low.  The  articular  furnishes  a  ball  for  articulation 
with  the  quadrate.  There  is  present  what  Baur  called 
a  presplenial,  but  which  is  here  regarded  as  the  true 
splenial,  a  bone  absent  from  most  turtles. 

The  hyoid  apparatus  is  greatly  developt,  but  need  not 
here  be  described. 

The    scapula   is    a    strong   bone.     The  procoracoid 
lation  of  quadrate  with  lower  jaw;  process  makes  Icss  than  a  tight  angle  with  the  body  of 

vom,  vomer.  ' ,       ,  j-,  ,  ~        .      ~      .         ,  .      ■^. 

the  bone.  Between  the  two  portions,  m  the  angle,  is  a 
sharp  crest.  The  glenoid  fossa  is  at  the  end  of  a  long  neck.  The  coracoid  is 
relatively  short,  much  bent  in  a  horizontal  plane,  and  expanded  at  the  free  end. 
The  humerus  resembles  that  of  the  emyds  in  most  respects.  The  ulnar  and 
radial  tuberosities  are  somewhat  larger,  the  ulnar  ascending  slightly  above  the  head, 
the  radial  descending  lower  than  in  the  emyds.    The  ulna  has  no  suggestion  of  an 


Fig.   6. — Hydromedusa.     Skull 
from  below.     Xj. 

bocy  basioccipital;  hsp,  basisphenoid; 
exoCj  exoccipital;  mr,  rnaxilla;  pa^ 
parietal;  pal,  palatine;  paoCy  paroc- 
cipital;  pmXj  premaxilla;  />/,  ptery- 
yoid;    qu^  quadrate;    qu.  art,  articu- 


14  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

olecranon.  The  tarsus  and  digits  do  not  differ  enough  from  those  of  emyds  to 
require  further  notice  here. 

The  pelvis  of  Hydromedusa  differs  greatly  from  that  of  the  emyds  and  triony- 
chids.  The  ilia  are  much  expanded  and  triangular  at  their  upper  ends,  and  have 
become  joined  by  a  rough  suture  with  the  eighth  costals.  The  lateral  processes  of 
the  pubes  are  stout  and  are  sutured  to  rough  surfaces  on  the  xiphiplastra.  The 
anterior  branch  of  the  pubis  is  slender  and  joins  its  fellow  at  the  midline.  The 
ischia  are  stout  bones,  sutured  to  the  hinder  border  of  the  xiphiplastra.  The  lower 
portion  of  each  ischium  expands  into  a  great  lateral  process,  which  runs  forward 
and  inward  to  join  the  one  from  the  other  side,  the  whole  length  of  each  process 
being  sutured  to  the  xiphiplastron.  There  is  no  bony  union  of  the  pubes  and  the 
ischia  along  the  median  line.  As  shown  by  Baur  (Jour.  Morphology,  iv,  1891,  p. 
351)  there  is,  in  many  Pleurodires,  a  greatly  lengthened  prepubic  cartilage.  It  is 
to  be  compared  with  the  prolongation  forward  seen  in  the  pubes  of  species  of 
Ba'ena  and  Chisternon. 

The  hinder  limb  does  not  differ  notably  from  that  of  the  emyds. 

Illustrations  are  here  furnisht  of  the  skull  of  Podocnetnis  expanse,  another 
Pleurodire,  the  structure  of  which  in  many  respects  strikingly  differs  from  that  of 
Hydromedusa.  From  plate  4,  fig.  I,  it  will  be  seen  that  the  temporal  region  is 
nearly  as  completely  rooft  over  as  is  that  of  Lepidochelys  (plate  i,  fig.  i).  There 
are  no  nasal  bones  and  the  supraoccipital  spine  is  long.  In  one  feature  of  the 
temporal  roof  this  turtle  is  different  from  Lepidochelys.  In  the  latter  the  postfrontal 
bone  extends  backward  nearly  to  the  hinder  border  of  the  roof;  in  Podocnemis 
the  postfrontal  bone  is  very  small  and  its  place  in  the  roof  is  mostly  occupied  by  the 
quadratojugal,  which  rises  over  the  squamosal,  excluding  the  latter  from  contact 
with  the  parietal  (plate  4,  figs.  1-5). 

Fig.  2,  plate  4,  represents  a  palatal  view  of  the  same  skull.  The  premaxillae  are 
of  considerable  size.  The  vomer  is  absent.  The  triturating  surface  of  the  maxilla 
is  broad  and  furnisht  with  ridges.  The  choanae  are  restricted.  The  palatines  are 
broad  and  meet  throughout  their  length  at  the  midline.  The  pterygoids,  too,  are 
broad,  little  separated  mesially  by  the  basisphenoid,  and  the  outer  border  of  each  is 
turned  upward  into  a  scroll-like  process.  The  articular  surface  of  the  quadrate, 
for  the  lower  jaw,  is  seen  to  be  concave. 

Fig.  5,  plate  4,  shows  the  same  skull  viewed  from  the  side. 

The  lower  jaw  (plate  4,  figs.  3,  4)  presents  a  ball-like  articular  surface  for  the 
quadrate.  In  front  of  this  are  seen  the  angular,  the  prearticular,  the  splenial,  and 
the  dentary,  the  latter  consolidated  with  its  fellow  at  the  symphysis  and  furnisht 
above  with  a  broad  and  ridged  triturating  surface.  On  the  outside  of  the  hinder  half 
of  the  ramus  is  the  supraangular. 

THE  DERMOCHELYID^E.    THE  LEATHERBACK  TURTLES. 

It  is  necessary  now  to  describe  in  brief  terms  the  skeleton  of  the  leatherback 
(Dermochelys  coriacea),  one  of  the  most  extraordinary  of  turtles.  It  attains  a  great 
size  and  is  the  most  thoroly  aquatic  turtle  that  is  known  (fig.  7).  Figures  of  all 
portions  of  the  skeleton  may  be  found  on  the  plates  illustrating  a  paper  by  Paul 
Gervais  on  this  turtle,  publisht  in  the  Nouvelles  Archives  du  Museum  d'Histoire 
Naturelle  de  Paris,  volume  viii,  1872. 

The  ribs  of  this  turtle,  instead  of  being  consolidated  with  costal  plates  that 
unite  edge  to  edge  to  form  a  carapace,  are  wholly  free  from  one  another.  The  first 
rib  is  wholly  free  from  the  second,  the  tenth  from  the  ninth.    The  only  thing  that 


OSTEOLOGY. 


15 


may  be  supposed  to  represent  the  costal  plates  is  the  irregular  border  of  the  some- 
what expanded  ribs.  Of  the  other  elements  entering  into  the  carapace  of  an  emyd 
or  a  pleurodirid,  the  leatherback  possesses  only  the  nuchal  bone. 

But  the  leatherback  has  a  carapace  peculiar  to  itself.  This  is  composed  of  a 
layer  of  thin,  polygonal  bones  which  are  buried  in  the  thick  skin  of  the  animal.  Of 
these  bones  there  are  7  rows  of  larger  ones,  that  appear  in  the  living  animal  as  so 
many  sharp  dorsal  keels.  One  of  these  rows  is  along  the  midline;  three  run  along 
each  side.  In  front,  this  layer  of  mosaic-like  bones  overHes  the  nuchal.  Smaller 
bones  fill  up  the  spaces  between  the  rows. 

On  the  inferior  side  of  the  turtle  there  are  5  rows  of  similar  bones,  but  the  spaces 
between  the  rows  are  not  so  completely  filled  as  on  the  upper  side.  Beneath  the 
skin  which  supports  these  rows  of  bones  there  is  a  ring  of  elongated  bones  which 
represent  the  plastron  of  more  normal  turtles.  These  represent  the  epiplastra, 
the  hyoplastra,  the  hypoplastra,  and  the  xiphiplastra.  The  entoplastron  is  missing. 
All  these  bones  are  slender  and  thin,  and  they  surround  a  vast  fontanel. 


Fig.  7. — Dermochelys  coriacea.    Greatly  reduced. 

The  cervical  vertebrae  differ  in  no  important  respect  from  those  of  Caretta,  and 
the  neck  is  equally  short.  The  dorsals  are  ten  in  number  and  immovably  joined  to 
those  in  front  and  behind  by  rough  articular  ends.  The  neural  arches  are  moved 
forward,  so  that  each  articulates  about  equally  with  its  own  centrum  and  that  in 
advance.  They  are  somewhat  expanded  above,  but  do  not  come  into  contact  with 
plates  from  the  ribs.  In  fact,  these  plates  are  extremely  vestigial.  There  are  two 
sacral  vertebrae,  whose  ribs  articulate  with  the  iha;  and  there  are  about  twenty 
caudals. 

The  skull  at  first  glance  presents  many  resemblances  to  that  of  members  of  the 
Cheloniidae.  The  temporal  roof  extends  backward  as  far  as  the  occipital  condyle. 
The  postfrontal  and  the  jugal  are  large,  and  the  squamosal  joins  the  parietal. 
The  supraoccipital  spine  is  short.  The  prefrontals  extend  backward  to  beyond  the 
orbits.  The  external  nares  look  forward  and  strongly  upward.  The  maxillae  are 
not  strongly  developt;  and  they  have  hardly  any  triturating  surfaces.  The  choanae 
are  placed  far  forward  and  open  directly  into  the  roof  of  the  mouth.  A  spHnt-like 
vomer  separates  them,  and  extends  backward  to  the  pterygoids.  The  palatines  are 
broad,  and  they  reach  forward  nearly  to  the  vomer,  sometimes  coming  into  contact 
with  it.  Thus,  they  bound  the  choanae  outwardly.  The  pterygoids  join  on  the  mid- 
line for  a  short  distance  only  in  front;  otherwise,  they  are  widely  separated  by  the 


l6  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

basisphenoid  and  the  basioccipital;  they  shut  off  the  latter  bones  from  contact 
with  the  quadrate.  The  inner  borders  of  the  pterygoids  lie  upon  the  upper  side  of 
the  basisphenoid. 

In  one  important  respect  the  leatherback  and  its  few  fossil  relatives  differ  from 
all  other  turtles.  This  is  in  the  fact  that  the  parietal  bone  does  not  send  downward, 
in  front  of  the  exit  of  the  trigeminal  nerve,  a  plate  to  join  the  pterygoid. 

The  occipital  condyle  remains  cartilaginous.  The  pedicel  of  the  quadrate  is 
slender  and  directed  strongly  forward.  The  lower  jaw  is  feebly  developt  and  fitted 
for  soft  food.  The  articular  remains  cartilaginous.  The  angular  and  the  supra- 
angular  are  short,  as  seen  from  the  outer  side  of  the  jaw,  but  are  prolonged  on  the 
inner  side.     The  prearticular  and  the  coronoid  are  not  present. 

The  parts  of  the  scapula  are  short  and  thick.  The  procoracoid  process  makes 
an  obtuse  angle  with  the  body  of  the  bone.  The  coracoid  bone  is  about  twice  as 
long  as  the  process  mentioned,  and  the  free  end  is  somewhat  expanded  and  flattened. 

The  humerus  is  a  massive  bone  and  much  flattened.  The  general  form  is  that 
of  the  humerus  of  Leptdochelys,  but  the  radial  tuberosity  is  brought  down  to  a 
point  more  than  half-way  from  the  head  of  the  bone  to  the  distal  end.  The  end 
for  articulation  with  the  ulna  and  the  radius  is  very  broad,  and  nearly  semicircular 
in  outline.  The  ectepicondylar  passage  is  a  foramen  wholly  in  the  bone,  about  the 
middle  of  its  width. 

The  radius  and  the  ulna  are  stout  bones  of  about  equal  length  and  only  about 
half  as  long  as  the  humerus.  The  carpus  has  2  bones  in  the  first  row,  a  centrale, 
5  bones  in  the  second  row,  and  a  large  pisiform.  Sometimes  the  fourth  and  the 
fifth  distal  carpals  are  co-ossified.  The  digits  have  the  normal  number  of  pha- 
langes; that  is,  2  in  the  thumb  and  3  in  each  of  the  others.  The  second,  third  and 
fourth  digits  are  greatly  elongated,  being  twice  the  length  of  the  humerus  measured 
from  the  head.  None  of  the  digits  bears  a  claw.  All  are  bound  together  in  a  com- 
mon envelope  of  skin  to  form  a  powerful  flipper. 

The  pelvis  is  in  many  respects  different  from  that  of  the  Cheloniidae.  The 
form  of  the  ilium  and  its  position  with  respect  to  the  pubis  do  not  differ  greatly 
from  those  of  the  ilium  of  Caretta,  but  the  ischia  are  broader  fore  and  aft  than  in 
Caretta.  The  pubes  are  connected  along  the  midline  for  a  much  greater  distance 
than  in  the  Cheloniidas.  Posteriorly  they  approach  the  ischia,  so  as  nearly  to  join 
them,  the  interspace  being  filled  by  cartilage.  The  ischio-pubic  foramina  are 
extremely  small  and  nearly  separated  in  the  midHne.  The  lateral  processes  are 
very  large,  extending  outward  and  forward,  so  that  at  their  extremities  the  pelvis 
is  twice  as  wide  as  it  is  across  the  narrowest  part  of  the  pubes.  Each  process 
terminates  in  a  large  plate  of  cartilage.  There  is  likewise  a  large  spatulate  prepubic 
cartilage. 

The  hinder  limb  is  reduced  in  size,  as  in  the  Cheloniidae,  and  offers  differences 
only  in  detail. 


MODIFICATION    IN    TURTLES.  1/ 

ON  THE  AMOUNT  OF  MODIFICATION  UNDERGONE  BY  TURTLES 
SINCE  THEIR  EARLIEST  APPEARANCE. 

On  preceding  pages  a  brief  exposition  has  been  presented  of  the  principal 
structures  shown  in  the  skeletons  of  turtles  of  various  groups.  It  is  now  intended 
to  consider  the  differences  of  structure  from  another  point  of  view,  that  of  determin- 
ing the  amount  of  differentiation  these  animals  have  suffered  since  their  earliest 
appearance,  especially  as  compared  with  the  changes  undergone  by  other  orders  of 
reptiles.  It  is  generally  supposed  that  turtles  have  been  unusually  conservative  in 
their  changes;  that,  as  in  their  movements  so  in  their  development,  they  have 
progrest  slowly.     We  are  to  inquire  to  what  extent  this  impression  is  true. 

Let  us  first  consider  the  shell,  that  part  which  is  most  often  found  preserved  in 
the  rocks  and  the  part  which  is  regarded  as  most  characteristic  of  turtles.  The 
theory  accepted  by  the  writer  is  that  originally  the  upper  side  of  the  body  was 
protected  by  a  rim  of  peripheral  bones,  a  median  row  of  neural  bones,  and  eight 
pairs  of  bony  plates  which  overlay  the  ribs  and  had  possibly  in  the  earliest  turtle 
coalesct  with  them,  probably  joining  one  another  by  their  contiguous  edges;  and 
that  in  addition  to  the  bones  enumerated,  subdermal  in  their  position,  there  was  a 
more  superficial  layer  of  bones,  dermal  in  position  and  forming  seven  longitudinal 
zones,  a  median  or  vertebral  zone,  two  costal,  two  supramarginal,  and  two  marginal 
zones.  The  plastron  was  formed  of  at  least  eleven  subdermal  bones,  while  super- 
ficially there  were  found  five  zones  of  dermal  bones,  a  median  and  two  lateral  on 
each  side  of  it.  Starting  with  this  outfit,  the  vast  majority  of  turtles  have  wholly 
or  almost  wholly  divested  themselves  of  the  dermal  layers  and  have  acquired  a  soHd 
shell  composed  of  the  subdermal  bones.  On  the  other  hand,  the  leatherback 
turtle,  Dermochelys,  appears  to  have  retained  the  dermal  and  to  have  almost  wholly 
surrendered  the  subdermal  bones,  for  the  costal  plates  now  form  only  unimportant 
fringes  on  the  ribs;  the  peripherals  and  neurals  are  wholly  gone;  the  nuchal 
is  reduced;  and  the  plastral  bones  are  only  eight  slender  rods.  As  regards  the 
carapace,  Dermochelys  possesses  little  that  is  homologous  with  that  of  most  other 
turtles. 

If  we  view  the  modifications  undergone  by  the  shell  within  the  group  known  as 
Thecophora  we  find  that  they  are  extensive.  We  can  hardly  doubt  that  the  primi- 
tive turtles  possest  a  pair  of  mesoplastral  bones;  and  yet  we  know  that  all  turtles 
have  discarded  these,  except  a  few  of  the  Pleurodira.  Within  the  latter  super- 
family  the  shell  has  not  suffered  remarkable  modifications.  Nevertheless,  most 
of  the  genera  have  no  mesoplastra.  In  some  the  plastron  is  connected  with  the 
carapace  ligamentously,  while  in  others  strong  axillary  and  inguinal  buttresses  rise 
from  the  plastron  and  articulate  with  the  inferior  surface  of  some  of  the  costals.  In 
all,  the  hindermost  costals  have  contracted  a  sutural  union  with  the  ilia.  In  a 
considerable  number  of  genera  the  neurals  have  become  wholly  supprest.  In 
Pelusios  (Sternothcerus)  there  is  a  hinge  behind  the  hyoplastra. 

In  the  superfamily  Trionychoidea  the  shell  has  undergone  extensive  reduction. 
No  traces  are  known  of  the  original  dermal  layer  of  bones.  The  neurals  and  the 
costal  plates  are  retained;  but  the  latter  show  retardation  in  their  development, 
attaining  the  distal  ends  of  the  ribs  not  at  all  or  only  at  a  late  date  in  life.  The 
peripherals  are  wholly  missing,  except  perhaps  in  the  genus  Trionyx  {Emyda  Gray). 
In  the  plastron  we  never  find  mesoplastra  and  all  the  bones  are  more  or  less  reduced. 
In  the  great  majority  of  cases  there  are  fontanels  on  the  midline  and  at  the  bridges. 
The  form  and  relations  of  the  entoplastron  and  the  epiplastra  are  very  different 
from  those  of  other  turtles,  but  homologies  are  easily  traced. 


l8  FOSSIL    TURTLES    OF    NOR!  H    AMERICA. 

It  is  in  the  extensive  group  of  Cryptodira  that  we  meet  with  the  greatest  number 
of  what  may  be  regarded  as  the  minor  modifications  of  the  shell.  If  we  except 
Toxochelys,  no  known  Cryptodire  shows  more  than  vestiges  of  the  ancient  layer 
of  dermal  bones.  In  some,  as  Protostega  and  Archelon,  of  the  Upper  Cretaceous, 
the  costal  plates  are  nearly  as  much  reduced  as  in  Dermochelys.  In  these  and  a 
number  of  other  genera  of  Cretaceous  turtles  the  peripherals  are  slender,  but  they 
persist.  Probably  the  neurals  are  never  wholly  absent.  The  elements  of  the 
plastron  degenerate  in  some  cases;  but,  with  the  exception  of  the  entoplastron  of  a 
few  genera,  all  persist. 

It  is  in  this  group  that  we  discover  the  greatest  variety  in  the  forms  of  the  shell, 
ranging  in  convexity  from  much  deprest  to  highly  vaulted  and  bombous,  and  from 
relatively  long  and  narrow  to  a  breadth  greater  than  the  length.  There  may  be 
one  or  more  carinae  on  the  carapace  and  its  free  borders  may  be  smooth  or  variously 
notcht  or  rolled. 

In  some  genera  of  Cryptodira,  as  the  snappers  and  the  sea-turtles,  there  are 
extensive  fontanels  between  the  distal  ends  of  the  ribs  and  others  at  the  sides  and 
the  middle  of  the  plastron.  In  most  Cryptodira  the  bones  are  solidly  articulated, 
abrogating  all  fontanels.  In  the  snappers  and  the  sea-turtles  again,  the  plastron 
is  only  ligamentously  joined  to  the  carapace.  In  other  genera,  as  Batagur,  Hardella, 
and  Echmatemys,  the  plastron  sends  up  powerful  axillary  and  inguinal  buttresses  to 
the  inside  of  the  carapace.     Between  these  extremes  there  are  all  gradations. 

Among  the  Cryptodira  there  is  a  great  variety  of  hinges  between  portions  of  the 
shell.  In  Cyclemys  there  is  a  hinge  between  the  hyoplastron  and  hypoplastron, 
and  both  these  bones  are  sutured  to  peripherals.  In  Terrapene  there  is  a  similar 
hinge,  with  the  bones  only  ligamentously  joined  to  the  carapace.  In  the  extinct 
genus  Ptychogaster  there  is  a  sliding  joint  between  the  hypoplastron  and  the  contig- 
uous peripherals.  In  Kinosternon  there  is  a  hinge  between  the  epiplastra  and  the 
hyoplastra,  and  another  between  the  hypoplastra  and  the  xiphiplastra.  In  Kinixys 
there  is  a  hinge  in  the  carapace  between  the  fourth  and  the  fifth  costal  plates. 

Attention  may  be  called  to  the  modifications  of  the  neurals  and  the  costal  plates 
in  Testudo.  The  neurals  are  alternately  large  and  octagonal  and  small  and  quadrate. 
The  costals  are  truncated  wedges,  placed  so  that  broad  and  narrow  ends  alternate 
both  next  the  neurals  and  the  peripherals. 

There  are  numerous  interesting  modifications  in  the  number,  form,  and  disposi- 
tion of  the  horny  scutes  of  the  shell  among  the  turtles.  There  are  supposed  to  have 
been  originally  12  rows,  or  zones,  of  these  scutes,  corresponding  to  the  12  rows  of 
dermal  bones  of  Dermochelys  and  the  ancestral  turtle.  A  scute  coincided  with  each 
bone.  In  each  row  some  scutes  grew  at  the  expense  of  the  others  and  persisted  even 
after  the  disappearance  of  its  supporting  bone.  Whole  rows  of  the  scutes  dis- 
appeared, as  the  supramarginals  and  the  median  plastral  row  of  most  turtles.  The 
supramarginals  are  represented  in  Macrochelys  by  a  few  scutes  over  the  bridges. 
The  anterior  and  posterior  ends  of  the  supramarginal  series  are  found  in  the  Triassic 
Proganochelys.  Many  genera  furnish  the  inframarginals,  as  nearly  all  the  Derma- 
temydidae.  In  the  Emydida;  all  have  vanisht  except  one  in  the  axillary  notch  and 
another  in  the  inguinal.  In  the  Baenidae,  the  Dermatemydidae,  and  the  Pleurodira 
we  find  the  middle  plastral  row  represented  by  the  intergulars.  Archa-ochelys 
Lydekker  and  Polythorax  Cope  present  more  posterior  scutes  of  this  row.  Between 
zyoungDermochelys  with  its  12  rows  of  epidermal  scutes,  with  many  in  each  row, 
and  Terrapene,  with  only  7  rows,  there  are  many  and  interesting  stages. 

But  the  Trionychidae  carry  the  reduction  of  the  scutes  to  the  extreme,  for  none  of 
the  whole  superfamily  shows  any  traces  of  these  whatever.     In  various  species  of  the 


MODIFICATION    IN    TURTLES.  IQ 

Other  groups  the  boundaries  of  the  scutes  are  not  visible  on  the  shells;  but  in  most 
of  these  cases  the  scutes  were  probably  very  thin  and  their  edges  did  not  impress 
the  bone.  In  the  living  Carettochelys  and  the  extinct  Pseudotrionyx,  both  Crypto- 
dires,  there  are  no  scutes. 

The  principal  characters  which  belong  to  turtles  in  general  will  be  given  on  a 
succeeding  page.  Besides  these  common  characters,  others  that  have  been  lost  or 
modified  were  possest  by  the  more  primitive  members  of  the  order.  Of  these  may 
be  mentioned  the  presence  of  nasals,  of  lachrymals,  and  of  an  extensive  roof  over  the 
temporal  region.  The  presence  of  this  roof  in  the  skulls  of  the  older  turtles  is  so 
general,  perhaps  rather  so  universal,  that  its  primitive  nature  can  hardly  be  doubted. 
Its  frequent  presence  in  the  skulls  of  the  lower  forms  of  living  turtles  and  its  general 
absence  in  the  case  of  the  higher  forms  confirm  this  conclusion.  This  roof  must  have 
been  inherited  from  the  Cotylosaurian  ancestors  of  the  order.  Otherwise,  we  must 
suppose  that  it  was  developt  during  the  history  of  the  chelonians  and  again  lost  by 
most  of  them.  It  appears  obvious  that  the  roof  has  been  reduced  in  proportion  to  the 
elongation  of  the  neck  and  the  ability  to  withdraw  the  head  beneath  the  shell.  In 
Dermochelys  and  the  Cheloniidae  the  roof  extends  backward  as  far  as  the  occipital 
condyle;  and  all  these  turtles  have  short  necks  and  can  furnish  beneath  the  shell 
little  protection  to  the  head.  In  the  snappers  the  roof  is  moderately  developt;  in 
most  of  the  Emydidae  and  all  the  Trionychoidea  the  roof  is  reduced  to  a  narrow 
postorbital  bar  and  to  a  zygomatic  bar.  In  some  species  of  Terrapene  and  in  some 
other  genera  the  zygomatic  bar  is  missing.  While  in  some  Pleurodira,  as  Podocnemis, 
the  roof  is  wide,  in  others  nothing  is  left  but  the  postorbital  bar.  Several  genera 
possess  a  parieto-squamosal  arch  (Rhtnemys,  Hydraspis,  Hydromedusa).  Dr. 
George  Baur  showed  the  various  ways  in  which  these  results  have  been  attained. 
In  the  Cryptodira  the  roof  has  been  eaten  away  from  behind  forward  and  in  front 
of  the  tympanic  cavity,  severing  first  the  union  of  the  parietal  and  the  squamosal, 
then  that  of  the  postfrontal  and  the  squamosal,  and  finally  in  rare  cases  that  of  the 
jugal  and  the  quadratojugal.  In  the  Pleurodira  the  reduction  has  followed  the 
reverse  course,  beginning  in  front  of  the  tympanic  cavity  and  moving  upward  and 
backward.  In  several  genera  of  Pleurodira  there  has  been  left  only  a  very  narrow 
parieto-squamosal  bar;  in  others,  not  even  this.  In  all  cases  the  removal  of  the 
bone  has  begun  at  one  border  or  the  other  of  the  bone  and  never  by  the  formation  of 
fontanels  in  the  roof. 

In  no  other  order  of  reptiles  do  we  find  such  enormous  variation  in  the  character 
of  the  temporal  roof.  Superfamilies  and  families  of  turtles  present  modifications 
that  would  characterize  orders  of  other  reptiles. 

The  palatal  region  offers  variations  in  structure  that  are  of  wide  range.  Primi- 
tively the  choanae  opened  in  the  front  of  the  mouth  one  on  each  side  of  the  narrow  and 
shallow  vomer.  A  broadening  of  the  triturating  surfaces  of  the  jaws  required  that 
the  choanae  be  pusht  backward.  This  was  accomplisht  by  the  development  of 
a  median  descending  plate  of  the  vomer,  which  spread  laterally  and  joined  palatal 
plates  from  the  maxillae,  the  palatines,  and  sometimes  even  from  the  pterygoids. 
Thus  a  floor  was  formed  beneath  the  nasal  channels,  carrying  these  backward 
sometimes  more  than  half-way  to  the  occipital  condyle.  The  process  is  similar  to 
what  occurred  in  the  order  of  Crocodilia;  only,  in  the  most  primitive  known  forms 
of  the  latter  the  choanae  are  placed  immediately  in  front  of  the  pterygoids,  while  in 
the  most  advanct  forms  the  choanae  are  in  the  rear  of  these  bones.  These  differences 
were  regarded  by  Huxley  as  sufficient  to  justify  the  recognition  of  two  groups  of 
crocodiles,  the  Mesosuchia  and  the  Eusuchia.  Variationsof  greater  extent  among  the 
turtles  characterize  famiUes  only  or  even  genera. 


20  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

The  jaws  have  suffered  extensive  modifications.  In  the  less  differentiated 
turtles  the  cutting-edges  of  the  jaws  are  low  and  the  triturating  surfaces  narrow. 
The  cutting-edges  may  become  deep,  without  increase  of  the  width  of  the  triturating 
surfaces  and  vice  versa.  For  an  illustration  of  great  width  of  the  grinding  surfaces 
the  reader  is  referred  to  the  species  Rhetechelys  platyops  (Cope). 

The  lower  jaw  becomes  modified  to  correspond  with  the  upper  jaw.  The  rami 
of  that  of  Toxochelys  latiremis  are  narrow  and  slender;  while  those  oi  Erquilinnesia 
are  broad,  flat,  and  fitted  for  crushing  hard  objects. 

The  vomer,  which  is  always  developt  in  the  Cryptodira,  the  Trionychoidea  and 
some  of  the  Pleurodira,  is  wholly  missing  in  some  forms  of  the  latter  superfamily. 

There  is  great  variation  in  the  pterygoids.  The  primitive  condition  appears  to 
be  essentially  that  now  found  in  the  Cryptodires  in  which  these  bones  are  of 
moderate  width  and  extend  backward  so  as  to  exclude  the  quadrates  from  contact 
with  the  basicranial  bones.  This  condition  exists  also  in  the  Amphichelydia  and 
the  Trionychoidea.  In  the  Pleurodira  the  pterygoids  have  become  shortened  poste- 
riorly, so  as  to  let  the  basicranial  bones  join  the  quadrates.  They  have  also  become 
expanded,  and  the  outer  edge  is  rolled  up  in  a  scroll-like  manner. 

The  necks  of  turtles  furnish  us  with  many  interesting  features.  There  is 
no  doubt  that  in  the  early  turtles  the  neck  was  short,  perhaps  less  than  half  as  long 
as  the  dorsal  series  of  vertebrae.  Doubtless  the  lengthening  has  been  brought 
about  to  facilitate  the  prehension  of  food,  but  it  has  had  other  consequences.  In 
some  species  of  each  of  the  superfamilies  of  Thecophora  the  neck  is  considerably 
longer  than  the  dorsal  series,  but  it  has  retained  its  primitive  shortness  in  Dermo- 
chelys  and  the  other  sea-turtles.  The  elongation  of  the  neck  is  never  due  to  any 
increase  in  the  number  of  vertebras,  but  to  the  lengthening  of  the  individual  vertebrae. 

The  most  important  modifications  of  the  cervical  vertebrae  are  to  be  found,  not  in 
their  mere  elongation,  but  in  the  structure  of  their  parts.  Originally,  as  we  learn 
from  Glyptops  pUcatulus,  the  vertebral  centra  were  all  biconcave.  In  Ba'ena  and 
Chisternon  we  find  the  beginnings  of  differentiation  in  the  articular  ends  of  the 
centra.  The  highest  stage  of  differentiation  is  perhaps  to  be  found  in  species  of 
Testudo.  In  Testudo  radtata,  of  Madagascar,  the  second  cervical  is  convexo- 
concave;  the  third  and  the  eighth  convexo-convex;  the  fourth,  fifth,  and  sixth, 
concavo-convex;  the  seventh,  concavo-concave.  The  joint  between  the  sixth  and 
seventh  and  that  between  the  seventh  and  the  eighth  are  elongated  from  side  to  side 
and  divided  into  right  and  left  portions,  forming  true  ginglymoid  articulations. 
Variations  of  this  arrangement  are  found  even  within  the  genus  Testudo.  Modifi- 
cations and  less  differentiated  stages  are  to  be  found  in  other  famiUes  of  Cryptodira. 

The  necks  of  the  Trionychoidea  are  usually  greatly  elongated  and  the  vertebrae 
are  essentially  as  in  the  Cryptodira.  The  Pleurodira  do  not  possess  ginglymoid 
joints,  but  in  at  least  one  genus  there  are  saddle-shaped  vertebral  articulations,  as 
in  birds. 

In  the  development  of  the  mechanisms  permitting  flexion  of  the  neck  two  distinct 
paths  were  followed,  the  Athecae,  the  Cryptodira,  and  the  Trionychoidea  taking  the 
one,  the  Pleurodira  the  other.  The  goal  reacht  in  each  case  is  very  different  from 
that  attained  in  the  other.  In  the  first  case,  the  neck  is  bent  in  a  perpendicular 
plane ;  in  the  case  of  the  Pleurodira,  in  a  horizontal  plane.  As  the  neck  of  members 
of  the  Cryptodira  and  Trionychoidea  lengthened,  the  head  began  to  be  withdrawn 
within  the  shell  for  protection.  In  the  case  of  the  Pleurodires  the  neck  is  bent 
laterally,  and  it  and  the  head  are  protected  by  the  projecting  borders  of  the  shell. 
If  the  neck  is  so  long  that  it  would  carry  the  head  beyond  the  axilla  it  is  bent  first 
in  one  direction,  then  in  the  other. 


MODIFICATION    IN    TURTLES.  21 

To  permit  these  different  modes  of  flexion  the  mechanical  arrangements  must 
be  different.  In  the  Cryptodires  and  the  trionychids  there  are  ginglymoid  joints 
at  the  base  of  the  neck,  facihtating  bending  in  a  perpendicular  plane.  The  neural 
arches  are  low,  with  the  zygapophyses  wide  apart,  favoring  motion  in  the  vertical 
plane,  restricting  it  in  the  horizontal.  In  the  Pleurodires  the  arches  are  high,  the 
zygapophyses  close  together,  often  confluent,  and  at  least  one  end  of  most  of  the 
centra  semiglobular,  arrangements  aiding  motion  in  a  horizontal  plane. 

It  is  doubtful  whether  there  is  another  group  of  vertebrates  that  possesses  so 
many  modifications  of  the  cervical  vertebrae  as  are  found  in  the  turtles. 

There  has  occurred  a  considerable  amount  of  modification  in  the  pelvis  of  these 
reptiles.  As  shown  by  Glyptops,  of  the  Jurassic,  and  Ba'ena  and  Chisternon,  of  the 
Bridger,  the  pelvis  was  not  originally  suturally  joined  to  the  shell.  In  both  the 
Cryptodires  and  the  trionychids  the  pelvis  has  retained  its  original  freedom.  In 
the  Pleurodires  the  ilia  effected,  before  the  close  of  the  Cretaceous,  strong  sutural 
connections  with  the  hindermost  costal  plates;  while  the  ischia  and  the  pubes 
became  closely  sutured  with  the  xiphiplastra. 

In  the  Amphichelydia  the  ischia  and  the  pubes  are  joined  along  the  midline  by 
a  bar  of  bone,  thus  defining  right  and  left  ischio-pubic  foramina.  In  the  Baenidae, 
so  far  as  known,  and  possibly  in  Glyptops,  the  prepubic  process  was  strongly 
ossified.  In  the  Emydidje  and  the  Testudinidae  the  ischio-pubic  bar  is  ossified;  but 
in  the  Cheloniidas  and  the  Trionychoidea  this  region  is  wholly  cartilaginous.  That 
the  primitive  condition  of  the  ischio-pubic  bar  and  of  the  prepubic  process  in  the 
Amphibia  and  the  early  Reptilia  was  cartilaginous  we  can  not  doubt.  That  these 
should  be  ossified  in  the  Amphichelydia  is  remarkable.  It  suggests  that  the  carti- 
laginous condition  in  so  many  hving  tortoises  may  be  due  to  degeneration. 

The  limbs  of  most  swamp-loving  turtles  present  primitive  conditions  of  the 
reptilian  hmb,  both  with  respect  to  their  composition  and  their  disposition.  The 
segments  of  the  Hmbs  are  mostly  flext  in  one  plane,  and  this  plane  stands  more  or 
less  at  right  angles  with  the  axis  of  the  body.  The  apex  of  the  angle  at  the  elbow 
is  directed  forward,  rather  than  backward  as  in  the  mammals,  and  the  ulna  and  the 
radius  do  not  cross.  There  have  occurred  few  unions  of  bones  and  these  are  con- 
fined to  the  carpus  and  the  tarsus.  No  bones  have  suffered  important  reductions 
or  modifications.  In  the  hmbs  of  swamp-inhabiting  turtles  there  have  been  few 
changes  since  Jurassic  times;  and,  since  the  Amphichelydia,  the  Cryptodira,  and 
the  Pleurodira  possess  similar  limbs,  it  is  evident  that  the  primitive  turtles  possest 
limbs  not  greatly  different. 

From  this  simple  type  of  limb  there  has  been  divergence  in  two  directions;  one 
to  adapt  the  animal  for  life  on  the  land,  the  other  for  habitual  hfe  in  the  water. 
The  highest  expression  of  the  former  adaptation  is  perhaps  to  be  found  in  the  limbs 
of  species  of  Testudo.  In  these  the  principal  modification  in  the  proximal  bones 
of  the  limbs  is  the  drawing  downward  and  toward  each  other  of  the  tuberosities  of 
the  humerus.  Most  important  is  the  shortening  suffered  by  the  bones  of  the  digits 
and  the  reduction  of  the  number  of  phalanges  in  each  to  no  more  than  two.  The 
fifth  hinder  digit  may  become  vestigial.  The  result  of  these  changes  is  the  pro- 
duction of  a  short  foot  resembling  that  of  an  elephant  and  adapted  for  travel  over 
rough  and  hard  ground. 

To  fit  the  animal  for  habitual  life  in  the  water  the  anterior  limb  tends  to  be 
converted  into  a  flipper.  First  of  all,  the  fingers  become  elongated  to  support  a 
broad  web.  Usually  the  number  of  phalanges  remains  unaffected.  In  the  Trio- 
nychidae  some  of  the  digits  are  much  elongated  and  the  phalanges  are  more  numerous 
than  the  normal,  and  two  of  the  claws  have  disappeared.     In  the  sea-turtles. 


22  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

never  coming  on  land  except  to  deposit  their  eggs,  the  fore  Hmbs  have  become 
transformed  into  definite  flippers  with  the  fingers  elongated  and  all  bound  together 
in  a  common  mass  of  skin  and  muscles.  Only  one  or  two  claws  remain.  The 
phalanges  and  carpals  are  considerably  flattened,  as  is  also  the  humerus.  The 
latter  also  becomes  straighter  and  the  insertions  of  the  deltoid  muscle  descend  on 
the  shaft.  While  these  changes  progrest  the  hinder  limb  became  relatively  smaller 
and  fitted  for  steering  the  animal.  The  extreme  of  these  modifications  is  to  be 
seen  in  the  limbs  of  the  leatherback,  Dermochelys.  Between  the  short  club-like 
foot  of  Testudo  and  the  long  and  powerful  flipper  of  Chelonia  and  Dermochelys  there 
is  a  vast  interval. 

Amid  all  the  changes  that  have  occurred  in  the  turtles  certain  fundamental 
structures  have  remained  unafi^ected.  The  jaws  have  always  retained  their  horny 
covering.  The  quadrate  has  remained  fixt.  The  cervical  vertebra;  have  kept 
unchanged  their  number,  8,  and  the  dorsals  their  original  number,  lo.  All  four 
of  the  limbs  have  persisted  and  all  the  segments  of  each. 

A  consideration  of  the  changes  which  turtles  have  undergone  and  a  comparison 
of  these  with  the  modifications  suffered  by  other  groups  of  reptiles  lead  to  the 
conclusion  that  no  other  order  of  these  animals,  except  the  Squamata,  can  display 
such  a  variety  of  structures.  The  Squamata,  embracing  the  mosasaurs,  the  lizards, 
the  chameleons,  and  snakes,  have  undoubtedly,  in  adaptation  to  different  modes 
of  life,  diverged  in  more  directions  and  gone  farther  than  have  the  turtles.  The  skull 
has  become  modified  in  more  ways;  the  vertebrae,  at  least  as  regards  the  number  in 
the  column,  have  varied  more;  the  limbs  have  undergone  more  varied  adaptations 
for  walking,  for  climbing,  for  grasping,  for  swimming,  for  leaping;  and  in  the  whole 
group  of  snakes  and  in  many  lizards  the  limbs  have  wholly  disappeared.  To  these 
denizens  of  the  earth,  swarming  since  probably  the  Triassic,  the  turtles  must  yield  in 
variety  of  form  and  structure  and  habits,  but  probably  to  no  other  order  of  reptiles. 


PRIMARY    AND    SECONDARY    CHARACTERS.  27, 

ON  THE  PRIMARY  AND  THE  SECONDARY  CHARACTERS  OF  TURTLES. 

It  may  be  interesting  and  productive  of  some  useful  result  to  endeavor  to  separate 
the  osteological  characters  that  belonged  to  the  most  primitive  turtles  from  those 
that  may  be  called  the  secondary  characters,  those  that  have  been  acquired  in  later 
times  through  the  exaggerated  development  or  reduction  or  the  suppression  of  cer- 
tain parts  ol  the  skeleton  or  their  modification  of  form  and  connections,  in  order  to 
adapt  them  to  new  uses.  We  will,  as  heretofore,  consider  first  the  shell  of  the  turtles. 

As  already  stated,  the  writer  holds  the  view  that  the  earliest  turtles  possest 
practically  two  kinds  of  shell,  one  purely  dermal,  consisting  of  probably  a  mosaic 
of  small  bones  arranged  in  at  least  12  longitudinal  zones.  Each  zone  probably 
consisted  of  a  row  of  larger  bones,  bordered  on  each  side  by  smaller  ones.  It  is  not 
necessary  to  suppose  that  the  spaces  between  the  zones  were  wholly  occupied  by 
these  smaller  bones.  Each  of  these  bones  was  covered  by  a  horny  scute.  The 
nearest  approach  to  such  a  dermal  shell  is  in  our  days  seen  in  Dermochelys,  as  has 
already  been  stated. 

Beneath  the  skin  there  seems  to  have  existed  a  carapace  more  or  less  complete 
which  consisted  of  a  nuchal,  a  median  row  of  neurals,  8  pairs  of  costals,  a  pygal, 
probably  one  or  more  suprapygals,  and  about  ii  peripherals  on  each  side.  To 
what  extent  the  neurals  and  the  costal  plates  had  become  anchylosed  to  the  neural 
spines  and  the  ribs  respectively  it  is  now  impossible  to  determine.  Nor  can  we  say 
to  what  extent  the  various  elements  of  this  carapace  had  become  connected  with  one 
another.  The  existence  of  the  dermal  carapace  would  appear  to  indicate  that  the 
subdermal  box  was  not  yet  closed.* 

There  was  a  subdermal  plastron  that  was  composed  of  at  least  11  bones. 
Portis  has  described  Polysternon,  which  had  an  additional  pair  of  bones  between  the 
hypoplastra  and  the  xiphiplastra,  making  13  all  together.  Between  these  various 
bones  there  may  have  existed  more  or  less  extensive  fontanels. 

According  to  the  author's  views,  as  time  went  on  the  external,  mosaic-like  shell 
disappeared  in  most  turtles,  while  a  more  efficient  armor  was  developt  out  of  the 
subdermal  elements.  In  the  ancestors  of  Dermochelys,  however,  the  dermal  armor 
was  retained,  while  the  more  deeply  seated  one  disappeared,  with  the  exception  of 
the  nuchal  bone. 

It  is  proper  to  state  that  all  authors  do  not  hold  that  Dermochelys  has  descended 
to  us  in  a  direct  line  distinct  from  other  sea-turtles,  but  has  been  derived  from  them 
at  a  more  recent  date.  On  this  subject  the  reader  must  consult  the  papers  of  Baur, 
Boulenger,  Case,  DoUo,  E.  Fraas,  Hay,  Van  Bemmelen,  and  Wieland. 

Most  Thecophore  turtles  have  lost  the  bones  of  the  outer  dermal  shell.  There 
are  yet  traces  of  it  perhaps  in  the  dorsal  and  ventral  keels  of  various  turtles,  in  the 
tubercles  that  diversify  these  keels,  and  especially  in  the  rows  of  horny  scutes  that 
had  their  origin  from  these  dermal  bones.  In  one  turtle,  however,  Toxochelys, 
of  the  Upper  Cretaceous,  there  are  yet  remains  of  the  dermal  armor  in  the  shape  of 
a  row  of  bones  along  the  dorsal  median  keel.  For  a  description  and  illustrations  of 
these  the  reader  must  consult  later  pages  of  this  work. 

In  a  paper  written  in  1898  (Amer.  Naturalist,  xxxii,  p.  929)  the  writer  denomi- 
nated such  bones  as  the  nuchal,  the  peripherals,  and  suprapygals  as  "fascia  bones." 
This  was  done  simply  to  distinguish  them  from  more  superficial  bones,  called 
dermal.  In  a  recent  paper  Mr.  H.  H.  Newman  (Biol.  Bull,  x,  p.  74)  has  referred 
to  this  paper  and  has  insisted  that  the  nuchal  is  a  dermal  bone.     Such  it  doubtless 

*For  Dr.  George  Baur's  latest  views  regarding  the  primitive  condition  of  the  carapace  and  plastron 
of  the  turtles  see  Anatomischer  Anzeiger,  xn,  1906,  p.  567. 


24  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

originally  was,  but  it  is  now  overlain  by  the  dermal  mosaic.  Mr.  Newman  holds  also 
that  the  peripherals  and  the  suprapygals  are  dermal  bones,  not  what  the  writer  called 
fascia  bones  or  subdermal  bones.  If  the  reader  will  consult  the  succeeding  pages  that 
deal  with  Toxochelys  he  will  see  that  one  of  the  dermal  nodules  overhes  the  second 
suprapygal.  1  he  latter  is  therefore  not  equivalent  to  the  row  of  nodules  in  front 
of  It  and  to  those  on  the  tail  of  the  snapping-turtle,  but  is  a  bone  of  a  deeper  layer. 

We  may,  therefore,  for  the  present  regard  the  characters  of  the  most  primitive 
turtles  as  having  been  the  following:  There  was  a  superficial  armor  composed  of 
dermal  bones  arranged  in  at  least  7  zones  above  and  at  least  5  zones  below,  with 
many  bones  in  each  zone,  and  each  bone  covered  by  a  horny  scute.  Beneath  this 
was  a  subdermal  armor.  On  the  upper  side  of  the  body,  this  consisted  of  the  nuchal, 
a  row  of  neurals,  8  pairs  of  costal  plates,  suprapygals,  and  peripherals;  below,  of 
the  entoplastron  and  at  least  5  pairs  of  subdermal  bones.  There  were  18  presacral 
vertebrae,  of  which  10  belonged  to  the  trunk  and  were  without  transverse  processes 
and  more  or  less  immovably  joined  to  each  other  and  to  the  ribs  and  neural  plates. 
The  neck  was  short  and  consisted  of  8  biconcave  vertebrae,  which  possest  transverse 
processes  and  low  neural  spines.  There  may  possibly  have  been  present  some 
cervical  ribs.  There  were  2  sacrals.  The  tail  consisted  of  biconcave  vertebrae, 
each  provided  with  free  ribs,  with  chevron  bones  below,  and  perhaps  with  one  or 
more  rows  of  bony  nodules  above. 

The  skull  had  a  complete  temporal  roof,  but  the  temporal  fossa  was  probably 
not  widely  open  behind.  There  were  nasals,  lacrimals,  and  prefrontals,  all 
distinct  from  one  another.  There  was  no  parietal  foramen.  A  vomer  was  present 
but  no  prevomers.  The  choanae  opened  far  forward  in  the  roof  of  the  mouth.  The 
quadrate  was  fixt,  somewhat  excavated  to  form  a  tympanic  cavity  and  notcht 
behind  for  the  stapes.  Probably  the  palate  was  closed  by  the  union  of  the  pterygoids 
with  each  other  and  with  the  basisphenoid.  The  parietals  may  or  may  not  have 
sent  down  each  a  plate  to  the  pterygoid,  in  front  of  the  exit  of  the  trigeminal  nerve. 
The  paroccipitals  were  free  from  the  exoccipitals.  The  jaws  were  without  teeth  and 
were  covered  by  a  sheath  of  horn.  Each  ramus  of  the  lower  jaw  was  doubtless  com- 
posed of  7  elements,  and  the  dentaries  were  probably  not  co-ossified  at  symphysis.  The 
outer  surface  of  the  bones  of  the  skull  was  covered  by  horny  scutes.  The  shoulder- 
girdle  consisted  of  a  pairof  coracoids,  a  pair  of  scapulae,  and  a  pair  of  procoracoids; 
the  latter  probably  co-ossifying  somewhat  late  in  Hfe  with  the  scapula.  Limbs,  fore 
and  hinder,  probably  not  greatly  different  from  those  of  living  Chelydridae,  but  more 
crudely  modeled.    The  phalangeal  formula  was  2,  3,  3,  3,  3  in  all  the  feet. 

If  the  views  exprest  above  regarding  the  original  composition  of  the  armor  of 
turtles  is  correct,  the  possession  of  a  carapace  consisting  exclusively  of  a  mosaic 
of  dermal  plates,  as  in  Dermochelys,  is  a  secondary  character;  as  is  likewise  the 
possession  of  a  shell  constituted  only  of  the  deeper  elements,  as  in  the  great  majority 
of  turtles.  Other  secondary  characters  are  the  absence  of  entoplastron  {Dermo- 
chelys, Kinosternon),  the  absence  of  peripherals  {Trionychoidea),  and  the  absence  of 
mesoplastra,  as  in  most  Hving  turtles.  Such  too  is  the  lack  of  nasals  and  lacri- 
mals in  the  great  majority  of  turtles.  The  adaptation  of  the  hmbs  for  habitual 
swimming  is,  of  course,  a  secondary  modification  of  these  organs. 

In  this  category,  too,  belong  those  modifications  of  the  cervical  vertebrae  by 
virtue  of  which  the  neck  has  become  so  greatly  elongated  in  most  forms  and  made 
most  freely  flexible  in  a  horizontal  plane  in  the  Pleurodira  and  in  a  perpendicular 
plane  in  all  the  others.  Most  extraordinary  of  all  the  secondary  characters  is  that 
complex  of  modifications  which  permits  the  head  and  neck  to  be  retracted  between 
the  scapulae,  the  loop  in  the  neck  sometimes  reaching  backward  quite  to  the  pelvis. 


CLASSIFICATION.  25 

THE  CLASSIFICATION  OF  THE  TURTLES. 

It  is  not  the  purpose  of  the  writer  to  give  here  an  account  of  the  various  schemes 
of  classification  that  have  been  proposed  by  writers  on  the  turtles.  For  such  an 
account  the  reader  may  consult  the  third  part  of  the  sixth  volume  of  Bronn's 
Klassen  und  Ordnungen  des  Thierreichs,  beginning  with  page  347.  The  following 
is  the  arrangement  ot  suborders,  superfamihes,  and  families  accepted  by  the  writer. 

All  of  these  families,  except  those  in  itahcs,  have  fossil  representatives. 

Order  Testudines. 
Suborder  I.  Athecae. 

Family.     Dermochelyidae. 
Suborder  II.  Thecophora. 

SuPERFAMiLY  I.  Amphichelydia. 

Families.     Pleurosternidae,  Baenidse,  Plesiochelyidae  ? 
SupERFAMiLY  2.  Pleurodira. 

Families.     Bothremyidae,  Pelomedusidae,  Chelyidae,  Miolanidse. 
Superfamily  3.     Cryptodira. 

Families.     Thalassemydidae,  Toxochelyidas,  Desmatochelyidas,  Protostegidae,  Cheloniids, 
Tretosternidae,  Chelydridae,  DermatemydidaE,  Platysternida,  Kinosternidie 
Carettochelydae,  Emydidae,  Testudinidae. 
Superfamily  4.  Trionychoidea. 
Families.     Plastomenidae,  Trionychidae. 

The  arrangement  and  names  of  the  suborders  and  superfamihes  above  given 
are  the  same  as  those  used  by  Mr.  George  A.  Boulenger  in  his  Catalogue  of  the 
Chelonia  of  the  British  Museum,  1889.  Mr.  Richard  Lydekker  employs  practically 
the  same  groups  in  his  Catalogue  of  the  Fossil  Reptilia  of  the  British  Museum, 
part  III,  1889;  but  to  some  of  his  groups  are  given  different  names.  Dr.  Louis 
DoUo,  of  Brussels,  also  divides  the  turtles  into  the  two  suborders  Athecae  and 
Thecophora.  Altho  this  eminent  writer  beheves  that  Dermochelys,  the  only  Hving 
representative  of  the  Athecae,  was  derived  from  the  Cheloniidae,  he  separates  it  as 
the  representative  of  a  distinct  suborder  on  account  of  its  extreme  modifications  of 
structure.  It  was  Cope  who  first  proposed  to  make  this  turtle  the  type  of  a  distinct 
suborder. 

In  his  Bibliography  and  Catalogue  of  the  Fossil  Vertebrata  of  North  America, 
1902,  the  present  writer  assigned  to  the  Trionychoidea,  under  the  name  Trionychia, 
the  rank  of  a  suborder.  A  further  consideration  of  the  subject  has  convinct  him 
that  these  turtles  should  rank  lower  than  a  suborder;  not  higher  than  a  super- 
family.  Indeed,  they  appear  to  have  brancht  ofi^  from  the  earliest  Cryptodira; 
but  their  hneage  is  so  ancient,  and  they  have  undergone  so  many  modifications  of 
structure,  that  they  are  of  equal  rank  with  the  Cryptodira.  The  skull  is  more  like 
that  of  the  Cryptodires  than  that  of  the  Pleurodires,  but  has  developt  pecuharities 
of  its  own.  Like  the  Cryptodires,  the  temporal  roof  has  never  been  eaten  away  from 
below,  and  always  a  zygomatic  arch  remains.  The  neck  is  wholly  cryptodiran  in 
its  modifications  and  is  retracted  within  the  shell  in  the  same  way.  This  is  a  feature 
unique  among  animals,  and  it  seems  improbable  that  it  could  be  hit  upon  independ- 
ently by  two  distinct  groups  of  turtles.  The  pelvis  in  its  parts  and  its  relationships 
to  the  shell  is  entirely  cryptodiran. 

Ernst  Haeckel,  in  his  Systematische  Phylogenie  der  Wirbelthiere,  1895,  page  326, 
has  taken  the  position  that  the  Trionychoidea  had  probably  arisen  already  in  the 
Triassic  and  that  they  are  to  be  lookt  upon  as  the  group  from  which  all  the  The- 
cophora have  been  derived.  That  the  group  was  establisht  even  in  the  Trias  is 
possible;  that  it  gave  origin  to  the  other  groups  of  Thecophora  seems  quite  impos- 


26  FOSSII-    TURTLES    OF    NORTH    AMERICA. 

sible.  None  of  the  superfamily  has  nasals,  lacrimals,  or  temporal  roofing.  Their 
derivatives  must  have  acquired  these  bones.  The  neck  is  most  completely  of  all 
turtles  adapted  for  retracting  the  head  within  the  shell.  To  give  origin  to  the  neck 
of  the  Pleurodires  this  neck  must  have  lost  its  peculiar  mechanisms  and  acquired 
those  of  the  side-neckt  or  snake-neckt  turtles.  To  have  produced  the  neck  found 
in  the  Amphichelydia,  that  of  the  Trionychoidea  must  have  shortened  greatly 
and  have  changed  its  biconvex  and  its  concavo-convex  vertebrae  into  biconcave 
ones.  The  Amphichelydia,  the  Cryptodira,  and  the  Pleurodira  must  have  developt 
peripheral  bones,  instead  of  inheriting  them  from  their  ancestors.  The  Amphiche- 
lydia and  many  Pleurodires  did  not  inherit  their  mesoplastral  bones,  but  acquired 
them  independently.  The  limbs  of  those  Thecophora  that  are  fitted  for  walking 
must,  according  to  the  scheme  of  derivation  proposed  by  Haeckel,  have  been  evolved 
from  feet  fitted  for  swimming.  Turtles  endowed  with  a  covering  of  horny  scutes 
came  from  a  race  which  are  wholly  devoid  of  these  coverings.  All  these  procedures 
are  the  exact  reverse  of  what  is  generally  beUeved  to  be  the  course  followed  by  animals 
in  their  evolution.  If  it  be  claimed  that  the  Trionychoidea  of  that  early  time  possest 
nasals,  lachrymals,  and  a  temporal  roof,  that  the  neck  was  yet  short  and  composed 
of  bicoelous  vertebrae,  that  they  had  peripheral  bones  and  mesoplastra,  then  they 
were  not  Trionychoidea  at  all,  but  Amphichelydia  or  something  very  close  to  them. 

It  is  a  difficult  matter  to  estimate  properly  the  relative  rank  of  the  three  super- 
famihes  of  the  Thecophora — the  Pleurodira,  the  Cryptodira,  and  the  Trionychoidea. 
As  to  the  Amphichelydia,  there  can  be  no  doubt  that  this  group  ranks  below  all 
the  others  and  that  from  it  have  been  derived  all  the  others.  It  appears  that  the 
Pleurodira  are  usually  regarded  as  the  most  speciaHzed  turtles.  There  is  no  doubt 
that  the  skull  and  the  pelvis  have  departed  farther  from  those  of  the  Amphichelydia 
than  have  those  of  either  the  Cryptodira  or  the  Trionychoidea.  The  most  im- 
portant modification  in  the  skull  is  the  posterior  shortening  of  the  pterygoids, 
whereby  the  basisphenoid  is  permitted  to  join  the  quadrate.  Likewise  the  outer 
anterior  border  of  the  pterygoids  has  become  rolled  up  in  a  peculiar  manner.  On 
the  other  hand,  the  skull  of  a  number  of  genera  has  retained  the  nasals  and  the 
posterior  notch  in  the  quadrate,  both  primitive  features.  It  seems  to  the  writer  that 
the  neck  is  less  specialized  than  that  of  the  Cryptodira  and  Trionychoidea.  The 
shell  has  undergone  far  less  specialization  than  that  of  the  other  groups  mentioned, 
many  of  the  genera  retaining  the  mesoplastra,  elements  unknown  in  the  others. 
On  the  whole,  the  writer  is  incHned  to  place  the  Pleurodira  below  both  the  Crypto- 
dira and  the  Trionychoidea. 

As  regards  the  Trionychoidea,  it  is  believed  that  the  skull  has  departed  further 
from  the  amphichelydian  pattern  than  has  that  of  most  of  the  Cryptodira.  This  is 
seen  in  the  universal  reduction  of  the  temporal  roof  to  narrow  postorbital  and 
zygomatic  arches,  the  backward  prolongation  of  the  squamosal  processes,  and  the 
closure  of  the  stapedial  notch  in  the  quadrate.  Altho  the  articular  ends  of  the  cer- 
vicals  present,  so  far  as  is  known,  less  variety  of  form  than  in  the  Cryptodira,  the 
neck  is,  as  has  been  said  by  Boulenger,  more  perfectly  adapted  for  complete  and 
rapid  retraction  than  in  any  other  chelonian.  The  carapace  has  become  greatly 
specialized  through  degeneration  of  the  peripherals  and  of  the  horny  scutes.  The 
Umbs  have  become  moderately  specialized  for  swimming.  The  Trionychoidea  can 
hardly  rank  below  the  Cryptodira;  it  is  convenient  to  let  them,  in  a  scheme  of 
classification,  follow  the  group  just  mentioned. 

In  fig.  8  an  attempt  has  been  made  to  indicate  the  connections  between  the 
different  famihes  of  turtles.  This  chart  differs  in  some  respects  from  the  one  pub- 
hsht  by  the  present  writer  in  the  Bulletin  of  the  American  Museum  of  Natural 


CLASSIFICATION. 


27 


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Fig.  8. — Phylogenetic  chart  showing  supposed  relationships  of  the  families 
and  higher  groups  of  turtles. 


28  FOSSIL  TURTLES   OF   NORTH   AMERICA. 

History,  volume  xxi,  1905,  page  167.  Since  the  publication  of  that  paper  discovery 
of  new  materials  has  shown  that  Anosteira  belongs  among  the  Dermatemydidae. 
The  family  Bothremydids,  recognized  in  the  present  work,  is  represented  in  the 
chart  as  springing  from  ancestral  Pelomedusidae  during  the  Lower  Cretaceous. 
It  is  wholly  possible  that  Taphrosphys  itself  belongs  to  the  PelomedusidcX,  instead 
of  the  Bothremydida;.  It  has  been  concluded  that  the  stock  that  gave  origin  to  the 
Emydids,  and  the  Testudinidae  ought  to  be  brought  into  closer  connection  with  the 
Dermatemydids.  The  Carettochelyidae  also  are  represented  as  arising  from  the 
Dermatemydidae.  It  is  not  improbable  that  they  should  have  been  regarded  as 
direct  descendants  of  the  Tretosternidae. 

The  geological  distribution  of  the  families  will  be  considered  on  a  coming  page. 

THE  DERIVATION  OF  THE  ORDER  OF  TURTLES. 

At  the  present  day  the  most  interesting  and  the  most  difficult  questions  that 
confront  the  student  of  any  group  of  animals  or  plants  are :  From  what  lower  group 
was  this  derived  .?  and:  What  are  its  relationships  to  kindred  groups  .?  We  must 
here  at  least  make  the  inquiry:  From  what  lower  order  of  reptiles  have  the  turtles 
been  derived  ?  and  the  further  inquiry:  What  are  the  relationships  of  this  order  to 
other  orders  of  reptiles  .?  The  reply  must  be:  We  can  not  yet  give  definite  answers 
to  these  questions. 

Nevertheless,  some  progress  appears  to  have  been  made  toward  framing  answers 
to  these  inquiries.  It  is  quite  generally  agreed  that  the  Cotylosauria  or  closely 
related  forms,  known  from  remains  occurring  in  Permian  deposits,  are  the  lowest, 
the  least  differentiated,  of  all  reptiles  hitherto  discovered,  having  themselves  been 
derived  directly  from  the  StegocephaHa.  On  this  point  see  Baur  (Anat.  Anzeiger, 
XII,  1896),  Cope  (Proc.  Amer.  Philos.  Soc,  xxx,  1892,  p.  279),  Osborn  (Mem. 
Amer.  Mus.  Nat.  Hist.,  viii,  1903,  p.  456),  Woodward  (Vert.  Palaeontology,  1898, 
p.  144),  Broile  (Palaeontographica,  li,  1904,  p.  106).  From  the  Cotylosauria,  Baur 
derived  the  turtles  thru  rhynchocephalian  ancestors,  animals  not  distantly  related 
to  Sphenodon.  Cope  concluded  (Proc.  Amer.  Philos.  Soc,  xxxv,  1896,  p.  124) 
that  the  cotylosaurian  Otocoelidae,  which  he  afterward  removed  to  the  order  Chely- 
dosauria  (Syllabus  of  Lectures,  1898,  pp.  54,  61),  were  the  source  of  the  turtles. 
Osborn,  as  cited  (p.  465),  brings  the  hne  of  descent  of  the  turtles  from  the  Coty- 
losauria through  the  Anomodontia.  Woodward,  as  cited  (p.  170),  calls  attention  to 
the  apparent  relationships  between  the  turtles  and  the  Anomodontia,  in  which  group 
he  includes  the  Cotylosauria  and  the  Chelydosauria.  Case  has  publisht  a  paper 
(Jour.  Geology,  xiil,  1905,  p.  126)  in  which  he  describes  a  species  of  Diadectes. 
In  this  communication  he  shows  that  the  family  of  Diadectidae  is  to  be  transferred 
to  the  Chelydosauria;  and  he  demonstrates  that  there  are  many  resemblances 
between  the  skull  of  his  specimens  and  that  of  turtles.  He  holds  that  we  have  in  the 
Diadectidae  "forms  veryclosely  related  to  the  ancestral  stem  of  the  turtles, which  tell  us 
much  regarding  the  development  of  the  Testudinata  directly  from  the  Cotylosauria." 

The  Cotylosauria  and  the  closely  related  Chelydosauria  indicate  their  eligibility 
to  stand  as  the  ancestors  of  the  turtles  by  the  possession  of  a  complete  roof  over  the 
temporal  fossa,  by  the  character,  rare  among  reptiles,  of  having  18*  presacral 
vertebrae,  by  the  existence  of  digits  having  the  phalangeal  formula,  2,  3,  3,  3,  3. 
Case  has  shown  that  the  claims  of  the  Diadectidae  for  the  honor  of  the  ancestry  of 
the  turtles  are  superior  to  those  of  the  Cotylosauria,  as  limited  by  him,  inasmuch  as 

*Broili  states  that  in  Lahidosaurus  hamatus  there  are  at  least  24  presacral  vertebrae. 


DERIVATION    OF    ORDER.  29 

in  Diadectes  the  temporal  roof  is  notcht  where  applied  to  the  quadrate  and  the  latter 
is  excavated  to  form  a  tympanic  cavity;  instead  of  a  pair  of  prevomers,  there  is  a 
single  vomer;  and  there  is  a  sort  of  carapace  composed  of  bony  plates  overlying 
several  pairs  of  the  ribs. 

It  seems  evident  that  we  are  getting  close  to  the  base  of  the  phylogenetic  tree  of 
the  chelonians;  but,  Hkewise,  that  we  have  not  yet  reacht  it.  Taking  into  con- 
sideration the  fact  that  no  turtle  possesses  a  temporal  fenestra,  that  when  the 
temporal  roof  is  deficient  either  the  zygomatic  arch  or  the  parietal  arch  or  both  are 
missing,  it  seems  impossible  to  derive  the  turtles  from  any  group  of  reptiles  in  which 
even  the  beginning  of  such  fenestrae  has  been  made.  If  this  view  is  correct,  there  are 
excluded  at  once  from  the  chelonian  ancestry  all  those  reptiles  belonging  to  Professor 
Osborn's  Diapsida  and  all  the  Anomodontia,  limited  so  as  not  to  include  the 
Cotylosauria.  The  Diadectidae,  too,  would  be  excluded,  if  they  really  possest 
temporal  fenestrae.  If  the  presence  of  a  pair  of  prevomers,  instead  of  a  vomer,  has 
the  importance  attributed  to  it  by  some  recent  authors,  the  Cotylosauria,  as  hmited 
by  Case,  would  have  to  forego  their  claims.  Of  known  reptiles  we  appear  to  be 
Hmited  to  the  Diadectidas  and  the  OtocoeHdae,  in  our  search  for  the  ancestors 
of  the  chelonians. 

It  is  improbable  that  any  of  the  reptiles  of  the  Permian  of  Texas  or  equivalent 
deposits  were  the  ancestors  of  the  turtles.  When  we  consider  that  already  in  the 
Upper  Trias  the  turtle  Proganochelys  possest  a  typical  shell,  we  must  conclude  that 
the  earliest  of  the  race  must  have  been  in  existence  as  early  as  the  Permian  itself. 
It  is,  of  course,  possible,  indeed  quite  probable,  that  some  earlier,  less  differentiated 
form  of  one  or  the  other  of  the  two  famiUes  just  mentioned  gave  origin  to  the  most 
primitive  turtles. 

It  is  a  serious  objection  to  any  of  the  Cotylosauria,  using  the  name  in  the  wider 
sense,  that  have  been  mentioned  as  possible  ancestors  of  the  turtles,  that  they  appear 
to  have  possest  no  ventral  armor.  Almost  certainly  the  turtles  inherited  this  portion 
of  the  shell,  in  some  form,  from  the  Stegocephalia.  The  Diadectes  described  by 
Case  presented  no  traces  of  a  plastron,  or  of  abdominal  ribs.  There  are  various 
other  reasons  why  this  reptile  can  not  pose  as  the  founder  of  the  chelonian  line. 
Among  these  are  the  elevated  spines  of  the  vertebrae,  the  great  amount  of  motion 
between  the  several  dorsal  vertebrae,  their  complex  structure,  the  anchylosis  of  the 
sacrals,  and  the  fact  that  the  plates  of  the  carapace  lie  between  the  scapula  and  the 
ribs.    In  turtles  the  scapula  lies  inside,  not  outside,  of  the  costal  plates. 

Dr.  O.  Jaekel,  of  Berlin,  has  described  (Neues  Jahrb.  Min.,  i,  1902,  p.  127)  an 
interesting  genus  named  by  him  Placochelys  and  regarded  by  him  as  standing  in 
ancestral  relations  to  the  turtles.  The  body  of  the  animal  is  short  and  broad,  and  is 
covered  by  an  armor  of  thick  small  plates,  all  closely  joined.  There  is  no  ventral 
armor.  The  specimen  was  found  in  the  lower  portion  of  the  Keuper.  The  well- 
preserved  skull  shows  that  there  were  large  supratemporal  fenestrae  and  that  the 
nasal  openings  were  separate  and  far  behind  the  end  of  the  snout.  These  structures, 
especially  the  first  named,  make  it  improbable  that  this  reptile  is  at  all  closely 
related  to  the  turtles. 

The  discovery  of  Otoccelus  and  Diadectes  and  Placochelys  is  like  the  capture  of 
so  many  stragglers  and  deserters  from  an  army  of  heterogeneous  composition. 
From  these  prisoners  we  may  learn  something  of  the  personnel  and  the  equipment 
of  that  army;  but  it  would  be  unsafe  to  draw  from  the  data  obtained  too  wide 
conclusions.  From  Placochelys  we  learn  that  in  Triassic  times  there  were  broad  and 
short  bodied  reptiles  of  tortoise-like  form  and  covered  with  an  armor  of  small  plates. 
From  Diadectes  and  Otoccelus  we  discover  that  in  Permian  times  there  were  more 


30  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

elongated  reptiles,  in  the  skulls  of  which  there  were  many  chelonian  characteristics 
and  whose  bodies  were  protected  by  an  armor  of  elongated  plates  overlying  the  ribs. 
The  stegocephalian  genus  Archegosaurus,  of  the  Permian,  possest  a  ventral  armor 
of  elongated  plates.  We  may  confidently  expect  that  in  the  Permian  there  will  yet 
be  found  an  animal  possessing  such  a  combination  of  these  characters,  together 
with  other  features,  that  we  can  recognize  in  it  the  ancestor  of  the  order  of  turtles. 

As  to  the  relationships  of  the  turtles  to  the  orders  of  reptiles,  other  than  the 
Cotylosauria,  only  a  few  words  can  be  said.  The  opinion  is  generally  maintained 
that  their  relationships  are  closer  to  the  Plesiosauria  than  to  any  other  order.  Baur 
(Jour.  Morphology,  i,  1887,  p.  98)  has  enumerated  a  number  of  resemblances 
between  the  two  groups.  Among  other  things,  he  states  that  the  pelvic  arch  of  the 
Nothosauridae,  among  the  most  primitive  of  the  Plesiosauria,  is  only  comparable 
with  that  of  the  Testudinata.  It  may  be  remarked  that  the  pubes  in  both  the  turtles 
and  the  plesiosaurs  are  greatly  expanded  forward  and  laterally.  The  ischia  are  not 
so  much  alike,  those  of  the  plesiosaurs  being  much  more  extended  backward  than 
those  of  the  turtles.  Baur  says  that  in  the  humerus  of  the  lower  Plesiosauria  there 
is  an  ectepicondylar  foramen;  but,  according  to  Fiirbringer,  there  is  only  an 
entepicondylar  foramen.  Baur  does  not  compare  the  skulls  of  the  two  orders.  The 
strongest  argument  in  favor  of  the  relationships  of  the  two  orders  is  found  in  sup- 
posed resemblances  in  the  shoulder-girdles.  Probably  the  best  presentation  of  this 
is  to  be  found  in  Fiirbringer's  elaborate  paper  in  the  Jenaische  Zeitschrift,  xxxiv, 
1900,  page  326.  In  that  treatise  the  author  takes  the  ground  that  the  process 
directed  interiorly  and  inwardly  from  the  scapula  in  the  turtles  is  a  procoracoid,  a 
view  adopted  by  the  present  writer.  Fiirbringer  also  holds  that  the  procoracoid 
was  present  in  the  Plesiosauria.  This  opinion  has  been  accepted  by  some  authors 
and  disputed  by  others.  To  the  present  writer  the  tract  of  bone  in  question  appears 
to  be  simply  an  extension  forward  and  mesially  of  the  scapula,  whether  that 
extension  is  regarded  as  an  acromion  or  a  "ventral  ramus"  of  the  scapula.  The 
tract  advanct  gradually  from  the  scapula  to  the  midline,  and  there  is  no  evidence 
that  it  ever  was  a  distinct  bone.  The  fact  that  the  two  clavicles  do  not  lie  between 
the  ends  of  these  processes  does  not  appear  to  be  decisive,  for  in  numerous  reptiles 
the  clavicles  extend  laterally  on  the  scapulae.  Opposed  to  the  idea  that  there  are  any 
special  relationships  between  the  turtles  and  the  plesiosaurs  are  the  facts  that  the 
latter  always  possess  large  supratemporal  fenestrae,  the  former  never;  and  that  the 
most  primitive  plesiosaur,  Lariosaurus,  has  the  digital  formula  belonging  to  the 
Diapsida  and  not  that  of  the  Synapsida. 

At  best,  the  relationship  between  the  turtles  and  the  plesiosaurs  is  not  close; 
and  the  most  that  we  can  say  is  that  possibly  the  cotylosaurian  stocks  of  the  two 
orders  were  a  little  closer  to  each  other  than  to  stocks  that  gave  rise  to  the  other  orders. 

THE  GEOGRAPHICAL  DISTRIBUTION  OF  LIVING  TURTLES. 

At  the  present  day  turtles  exist  in  all  the  larger  divisions  of  the  earth,  wherever 
there  is  sufficient  heat,  at  least  a  moderate  amount  of  moisture,  and  a  supply  of  food. 
They  occupy  too  all  the  warmer  seas.  Fig.  9  is  an  outline  map  that  includes  all  the 
lands  and  seas  in  which  these  reptiles  are  found.  The  areas  occupied  by  the  land  and 
fresh-water  forms  are  indicated  by  parallel  rulings,  except  that  certain  small  islands 
are  made  black ;  but  no  attempt  has  been  made  to  show  the  distribution  of  the  marine 
species.  Their  realm  may  be  taken  as  comprising  all  the  seas  between  the  ruled  areas. 
This  map  and  those  succeeding  it  have  been  compiled  with  considerable  care;  but 
it  is  not  possible  in  all  cases  to  determine  exactly  the  limits  of  the  groups. 


GEOGRAPHICAL    DISTRIBUTION. 


31 


A  glance  at  fig.  9  will  show  at  once  the  great  influence  of  heat  and  cold  and  the 
lack  of  moisture.  In  western  Europe,  warmed  by  the  sea,  the  turtles  are  represented 
by  a  species  which  ranges  nearly  as  far  north  as  St.  Petersburg;  while  in  Central 
Asia  none  is  known  to  occur  north  of  Turkestan  and  the  Himalaya  Mountains. 
The  southern  portion  of  Arabia  and  the  greater  portion  of  the  Sahara  Desert  are 
without  turtles,  on  account  of  the  dryness  of  the  climate.  In  North  America  the 
high  and  cold  range  of  the  Rocky  Mountains  supports  no  chelonian  life.  On  account 
of  its  dryness,  the  western  coast  of  South  America  has  no  turtles;  and  the  southern 
extremity  of  the  continent  none,  on  account  of  its  coldness.  So  much  can  we  say 
with  regard  to  turtles  in  general;  but  when  we  come  to  study  the  difi^erent  groups 
we  shall  find  that  they  are  often  absent  from  regions  where  the  conditions  appear 
to  be  wholly  favorable  for  their  existence. 


Fig.  9. — Map  showing  geographical  distribution  of  living  turtles,  excepting  those  strictly  marine. 
Occupied  areas  ruled  with  parallel  lines,  except  some  small  islands,  which  are  in  solid  black. 

Fig.  10  is  intended  to  display  the  distribution  of  the  Cryptodira.  It  is  seen  to 
differ  from  the  previous  map  principally  in  that  it  shows  that  AustraHa  possesses  no 
representatives  of  the  superfamily. 


Fig.  10. — Map  showing  geographical  distribution  of  the  Cryptodira. 

The  absence  of  Cryptodira  from  Australia  is  evidence  that  that  region  has  for 
many  geological  ages  been  cut  off  from  the  regions  to  the  north  of  it.  It  appears 
certain  that  had  the  turtles  of  this  superfamily  once  gained  access  to  this  region  they 
would  have  flourisht  there.     In  numbers  the  Cryptodira  exceed  today  all  other 


3« 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


groups  of  turtles  combined.  Accepting  the  genera  and  species  as  described  by  Mr. 
George  A.  Boulenger  in  his  Catalogue  of  the  Chelonians,  there  are  30  genera  of 
Cryptodira  with  140  species;  21  genera  of  Pleurodira,  with  24  species;  6  genera  of 
Trionychidae,with  24  species.  The  headquarters  of  the  superfamilyisNorth  America. 


Fig.  II. — Map  showing  geographical  distribution  of  the  Chelydridae.     Portions  of  the  western 
hemisphere  and  the  island  of  New  Guinea. 

Fig.  1 1  shows  the  distribution  of  the  Chelydridae.  The  northern  limits  of  the 
family  are  somewhat  uncertain.  The  same  species,  Chelydra  serpentina,  that  occurs 
in  Canada,  is  found  also  in  Ecuador,  South  America.  Until  recently  it  has  been 
supposed  that  the  members  of  this  family  are  confined  to  the  New  World;  but  J. 
Douglas  Ogilby  has  reported  (Proc.  Roy.  Soc,  Queensland,  xix,  1905,  p.  11)  the 
discovery  of  a  new  genus  and  species,  Devisia  mythodes,  in  the  Fly  river.  New 
Guinea,  the  river  that  has  furnisht  likewise  the  remarkable  turtle  Carettochelys. 
The  New  Guinea  snapper  has  a  length  of  860  mm.,  the  carapace  being  330  mm. 
long.  This  distribution  of  the  snappers  is  even  more  remarkable  than  that  of  the 
camels  and  tapirs. 


Fig.  12. — Map  showing  distribution  of  the  Dermatemydidae. 

Fig.  12  displays  the  distribution  of  the  Dermatemydidae.  This  is  one  of  the 
decadent  families  of  the  order,  for  it  abounded  in  genera  and  species  in  the  Upper 
Cretaceous  of  North  America  and  still  existed  in  reduced  numbers  during  the  Ter- 
tiary. The  family,  now  consisting  of  three  genera  and  four  species,  is  confined  to 
portions  of  Mexico  and  Central  America. 

As  seen  from  fig.  13,  the  Emydidae  have  a  wide  distribution,  occupying  all  the 
habitable  portions  of  North  America,  South  America,  Europe,  Asia,  and  most  of  the 


GEOGRAPHICAL    DISTRIUUTION. 


33 


P'.ast  Indian  islands.  They  are  wholly  missing  from  Australia  and  are  conspicuously 
restricted  in  Africa.  Only  2  species  occur  in  the  latter  continent,  and  it  is  possible 
that  one  of  these  was  introduced  by  man,  since  it  inhabits  also  the  south  of  Europe. 
Additional  remarks  on  the  distribution  of  the  family  will  be  found  under  the  head 
of  Emydida^,  on  a  subsequent  page.  Unless  the  genus  Gyremys  belongs  really  to 
the  Emydidae,  the  known  members  of  the  family  appeared  at  about  the  same  time 


KiG.  i^. — Map  showing  geographical  distribution  of  the  Emydidae. 

in  America  and  Europe,  in  the  Lower  Eocene.  It  is  remarkable  that  no  members  of 
the  group  were  able  to  find  their  way  into  Africa  with  the  Testudinidae,  for  the  latter 
were  estabhsht  there  by  the  time  of  the  Upper  Eocene. 

The  Emydidae  that  occur  in  South  America  are  all,  without  doubt,  descendants 
of  those  that  entered  that  continent  at  a  rather  late  period  from  North  America. 
This  was  probably  during  the  Pliocene.  Only  4  species  are  known.  Of  these  i 
belongs  to  Trachemys,  represented  by  several  species  in  North  America,  and  3  to 
Ntcorta,  a  genus  occurring  also  in  eastern  and  southern  Asia.    Nicoria,  however. 


Fig.  14. — Map  showing  geographical  distribution  of  the  Testudinid*. 

does  not  appear  to  be  greatly  different  from  Echmatemys  of  the  Bridget  beds,  yet 
distinct;  and  it  is  wholly  probable  that  both  Asia  and  South  America  received  their 
stock  from  our  own  country.  The  distribution  of  these  turtles  resembles  that  of  the 
tapirs.     North  America  possesses  at  least  25  species  of  P^mydidae. 

In  fig.  14  we  have  a  map  representing  the  distribution  of  the  Testudinid;e,  at 
present,  or  at  least  within  historic  times.  It  will  be  observed  that  North  America, 
which  during  the  Tertiary  was  probably  everywhere,  except  in  the  coldest  parts, 


34 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


inhabited  by  these  land  tortoises,  presents  only  two  very  restricted  areas.  Tho  at 
that  time  it  abounded  in  representatives  of  the  family,  some  of  them  of  gigantic  size, 
it  is  now  poor  in  species,  there  being  only  3.  Almost  the  whole  of  South  America 
is  occupied  by  the  family,  but  there  are  only  3  known  species.  Europe  claims 
2  species;  while  Asia  possesses  7.  Africa  is  the  headquarters  of  the  family,  at 
least  20  species  occurring  on  that  continent.  These  belong  to  3  recognized  genera. 
The  most  remarkable  feature  of  the  distribution  of  the  Testudinidae  is  the  occurrence 
of  species,  some  of  great  size,  on  islands  far  away  from  any  large  body  of  land,  as  the 
Galapagos  Islands  and  islands  in  the  Indian  Ocean.  For  further  discussion  of  this 
subject  the  reader  is  referred  to  the  treatment  of  the  family  on  a  succeeding  page. 
The  geographical  distribution  of  the  Pleurodira  is  represented  by  fig.  15.  It 
will  be  seen  that  the  species  are  almost  wholly  residents  of  the  torrid  and  the  south 
temperate  zones.  A  single  species  has  an  outlying  colony  on  the  Tropic  of  Cancer, 
at  the  head  of  the  Red  Sea.  The  wide  distribution  of  these  turtles  is  not  surprising, 
seeing  that  they  are  a  very  ancient  group.  The  earliest  species  that  are  known  to 
belong  to  the  superfamily  are  described  in  the  present  work  and  come  from  the 
Upper  Cretaceous  of  New  Jersey  and  New  Mexico.     Doubtless  the  group  existed 


Fig.  15. — Map  showing  the  distribution  of  the  Pleurodira. 

during  the  Lower  Cretaceous  and  probably  during  the  Jurassic.  In  those  early 
days  the  land  masses  had  connections  very  different  from  those  now  obtaining; 
and  these  turtles  were  able  to  become  diffused  to  regions  now  widely  separated  by 
deep  seas  from  the  original  home  of  the  creatures.  It  would  appear  more  reasonable 
to  suppose  that  South  America  had  received  its  original  pleurodiran  population 
from  North  America,  by  the  way  of  some  Mesozoic  land  connection;  but  it  is 
possible  that  these  immigrants  reacht  that  continent  from  Africa.  A  considerable 
number  of  authors,  viewing  the  subject  from  different  positions,  have  concluded  that 
there  was,  during  the  Mesozoic  era,  a  land  connection  between  South  America  and 
Africa,  which  connection  was  interrupted  about  the  beginning  of  the  Tertiary. 
The  existence  of  such  a  bridge  would  enable  us  to  account  for  the  occurrence  of 
some  closely  related  species  in  Madagascar  and  South  America.  These  species  are 
usually  referred  to  the  genus  Podocnemis;  but  Baur  regarded  the  Madagascar 
species  as  belonging  to  the  closely  related  genus  Erymnochelys.  Two  species  of 
Podocnetms  are  reported  from  the  Middle  Eocene  beds  of  the  Fayum,  Egypt. 

Inasmuch  as  Pleurodires  once  occupied  a  large  part  of  the  north  temperate  zone, 
it  is  remarkable  that  they  have  not  been  able  to  maintain  themselves  there.  The 
first  and  the  last  that  are  known  to  have  lived  in  North  America  flourisht  during 


GEOGRAPHICAL    DISTRIBUTION.  35 

the  Upper  Cretaceous.  In  England  species  existed  during  the  Eocene  and  a  species 
of  the  same  epoch  has  been  described  from  India  as  a  Hydraspis,  a  genus  now 
existing  in  South  America.  It  is  worthy  of  note,  too,  that  in  North  America  the 
Pleurodires  apparently  disappeared  long  before  the  Amphichelydia  did,  the  stock 
that  gave  origin  to  the  Pleurodires.  The  Amphichelydia  continued  on  into  the 
Bridget  and  the  Uinta. 

It  will  be  observed  from  the  map  (fig.  i6)  that  the  Trionychidae  occupy  the 
habitable  portion  of  North  America  east  of  the  Rocky  Mountains;  Africa  south  of 
the  Sahara  Desert;  Asia  south  of  the  Sayanskii  and  Yablonoi  Mountains  and 
between  the  Persian  Gulf  and  the  Caspian  Sea;  and  most  of  the  East  Indian  islands, 
including  New  Guinea.  Altho  the  oldest-known  representatives  of  the  TrionychidEe 
have  been  found  in  the  middle  of  the  Upper  Cretaceous  of  North  America  and  ahho 
that  continent  is  still  inhabited  by  at  least  6  species,  it  is  Asia  that  furnishes  the 
greatest  number  of  living  forms  of  the  family,  at  least  15  species  having  been 
described  from  that  region,  including  the  islands  appertaining  to  it.  In  Africa  there 
occur  about  6  species,  so  far  as  now  known.  As  in  the  case  of  the  Cryptodires,  the 
trionychids  have  prest  southward  close  to  Austraha,  without  having  succeeded  in 


Fig.  16. — Map   showing  the  distribution  of  the  Trionychidae. 

reaching  it,  Pelochelys  cantoris  having  been  reported  from  New  Guinea.  No  Triony- 
chidae have  been  found  in  the  Tertiary  beds  of  the  Fayum,  Egypt.  Considering 
the  fact  that  true  trionychids  antedate  known  pleurodirids,  it  appears  strange  that 
the  former  were  not  able  to  reach  Austraha  with  the  pleurodirids;  more  especially 
since  the  trionychids  are,  and  have  been  since  the  Judith  River  epoch,  excellent 
swimmers.  A  problem  fully  as  hard  to  solve  is  the  absence  of  trionychids  from  the 
continent  of  South  America.  So  far  as  we  can  judge,  they  might  easily,  within 
rather  recent  geological  times,  have  made  their  way  thither  from  North  America. 
Again,  Ameghino  has  described  what  he  regards  as  a  species  of  Trionyx  from  the 
Cretaceous  of  Patagonia.  The  description  is  very  brief  and  no  figures  have  been 
furnisht.  If  representatives  of  the  superfamily  had  reacht  the  continent  by  the 
time  of  the  Upper  Cretaceous  it  is  remarkable  that  they  were  not  able  to  maintain 
themselves  there.  No  region  appears  to  be  better  adapted  than  this  for  river-loving 
species  of  turtles. 

In  Europe  we  have  another  illustration  of  the  fact  that  animals  may  be  driven 
from  a  region  in  which  they  have  once  obtained  foothold.  No  species  of  the 
superfamily  now  occupies  that  region;  but  numerous  species  did  exist  there  during 
the  Eocene,  the  Oligocene,  and  the  Miocene.  It  has  not  yet  been  determined 
what  the  influences  were  that  operated  against  them. 


36 


I'OSSII.    lURTI.KS    Ol'    NORTH    AMHRICA. 


THE  GEOLOGICAL  DISTRIBUTION  OF  THE  TURTLES. 

In  tables  i  and  2  the  writer  has  endeavored  to  present  in  as  accurate  and  effective 
a  manner  as  possible  the  chronological  distribution  of  the  fossil  turtles  of  North 
America,  with  the  positions  of  the  turtle-bearing  beds  and  the  level  at  which  each 
species  has  been  found.  Table  i  represents  the  principal  divisions  and  subdivisions 
of  the  Me.sozoic  age,  except  the  Triassic,  while  table  2  deals  in  like  manner  with  the 
Cenozoic.  No  small  difficulty  is  experienct  in  the  preparation  of  such  tables.  The 
limits  of  the  larger  formations  and  the  periods  which  they  represent  have  not 
received  general  acceptance;  and  when  we  come  to  consider  the  smaller  divisions 
and  the  correlation  of  deposits  in  distant  regions  there  are  in  many  cases  widely 
divergent  views.  Again,  in  the  collection  of  the  fossils  there  has  often  been  too 
little  care  exercised  in  preserving  records  of  localities  and  levels.  An  interroga- 
tion mark  (.?)  preceding  any  generic  name  indicates  that  the  species  immediately 
succeeding  possibly  does  not  belong  to  the  level  indicated. 

Table  i. — Principal  divisions  of  the  "Jurassic  and  Cretaceous,  with  the  species  of  turtles  known  from  each. 


Denver. 

?  Glyptops  depressus. 

Arapahoe. 

Adocus  ?  lineatus,  Plastomenus .'  punctulatus,  P.  insignis,  Aspideretes  vagans. 

Baena  marshi 

,  B.  hatcheri,  Eubaena  ccphalica,  E.  latifrons,  Thcscelus  insil- 

Laramie. 

iens,  T.  ra] 

iens,  rNaiadochelys  ingravata,  Basilemys  sinuosa,  Compsemys 

victa,  C?  obscura,  Helopanoplia  distincta,  Aspideretes  fovcatus,  A.  beech- 

Fox  Hills. 

cri,  A.  austerus,  A.  fontanus,  A.vorai. 

No  turtles  known. 

Bear  Paw. 

No  turtles  known. 

Eastern  Region. 

(Greensand,  etc.,  aporoximatelv 

Baena      callosa,     B.  .             equivalent  to  Pierre,  etc.)             i 

antit]ua,    Boremys 

Bothremys  cooki,  Taphrosphys  sul- 
catus,  T.  longinuchus,  T.  leslianus, 

pulchra,  Neuranky- 

lus  eximia,  Chari- 

T.  strenuus,  T.  molops,  T.  nodo- 

temys  captans, 

sus,  T.  dares,  Ainblvpeza  entellus, 

Polythorax  missuri- 

Osteopygis  emarginatus,  O.  gibbi, 

ensis,  Basilemys 

O.  robustus,  O .  chelvdrinus,  O.ero- 

variolosa,     B.  im-  i        sus,  O.  borealis,  O.  platylomus,  O. 
hricaria,  ?Compse-          sopitus,    Catapleura    repanda,   C. 

Judith  River. 

Upper 
Cretaceous. 

Pierre. 

mysvicta,Gyremys          ponderosa,     Peritresius     ornatus, 
spectabilis,  Plasto-          I.ytoloma  angusta,  L.  jeanesi,  L. 
menus   costatus,              wielandi,    Erquelinnesia    molaria. 

Aspideretes   fovea- 

Rhetechelys      platyops,      .^Neptu- 

Mesozoic. 

tus,  A.  coalescens, 
A.   splendidus,    A. 
beecheri. 

nochelys    tuberosa,    Atlantochelvs 

mortoni,  Adocusbcatus,  A.puncta- 

tus,  A.  lacer,  A.  syntheticus,  A. 

agilis,  A.  pravus,  Agomphus  turgi- 

diis,   A.   petrosus,  A.  tardus,  A. 
pectoralis,  A.  firmus,    A.  masculi- 

Oagget. 

Toiochelys    latire- 

mis  ?,  Porthochelys 

nus,  Zvgoramma  striatula,  Z.  micro- 

Eagle. 

browni,     Archelon 

glvpha,      Homorophus      insuetus, 

ischyros,  A.  marshi. 

Amyda  =  prisca,  .\J  halophila. 

Toxochelys  latiremis,  T.  serrifer,  T.  brachyrhina,  T.  steno- 

Niobrara. 

pora,  T.  elkader,  T.  procai,  T.  bauri,  Cynocercus  incisus, 
Porthochelys    laticeps,    Protostcga    gigas,    P.    potens,    P. 

advena. 

BentoD. 

Glyptops  pervicax,  Desmatochelys  lowi. 

Dakota. 

No  turtles  known. 

Lower 
Cretaceous. 

Washita. 

Glyptops  ?  belviderensis. 

Fredericksburg 

. 

No  turtles  known. 

Trinity. 

Glyptops  cselatus  (In  Potomac  beds). 

Jurassic. 

Morrison. 

Glyptops  plicatulus,  Probai-na  sculpta. 

Unkpapa. 

No  turtles  known. 

Sundance. 

No  turtles  known. 

GEOLOGICAI,    DISTRIBUTION.  37 

Table  2. — Principal  divisions  of  the  Cenozoic,  with  the  names  of  the  turtles  found  m  each. 


Ceuozoic. 


Pleisto- 
cene. 


Pliocene. 


Miocene. 


Oligocene. 


Chelydra  serpentina,  Clen:iniys  percrassa,  C.  insculpta,  Chrvsemys  timida,  Trachemys  petrolei,  T. 
bisornata,  T.  trulla,  Terrapene  marnochi,  T.  eurypygia,  ?T.  canaliculata,  Testudo  laticaudata,  T. 
hexagonata,  T.  atascosae. 


Peace 
Creek. 


Blanco. 


Upper. 


Middle. 


Lower. 


John  Day. 


Macroclemysfloridana,  Deirochelys  fioridana,  Trachemys  sculpta,  T.jarmani,  T.  euglypha, 
Pseudemys  extincta,  Terrapene  putnami,  Testudo  crassiscutata,  Platypeltis  ferox? 


Testudo  turgida,  T.  pertenuis,  T.  campester,  CIcmmys  hesperia     (Rattlesnake  beds). 


Plains  and  Mountain  Region.  Yorktown  Epoch  of  Atlantic  Region. 

Trachemys   hilli,   Testudo    orthopygia,    T.     Syllomus    crispatus,    Procolpochelys    gran- 


edec,  T.  hollandi,  T.  impensa,  T.  niobra- 
rensis,T.  gilberti,  T.  undata,  T.  klettiana. 


daeva,  Amyda?    buiei,  A.?  lima.  A.?  cel- 
lulosa. 


Clemmys  saxea,  Testudo  pansa,  T.  osborniana^  T.  farri. 


Testudo  vaga,  T.  arenivaga,  T.  peragrans,  T.  inusitata,  T.  emiliae. 
Stylemys  oregonensis,  S.  capax,  S.  conspecta,  ?S.  calaverensis. 


Brule. 


Styieinys  nebrascensis,  Testudo  thomsoni,  T.  laticunea,  T.  ligonia,  T.  amphithorax,  T. 
quadrata,  T.  cultrata. 


Eocene. 


Chadron. 


Uppe 


Middle. 


Xenochelys   formosa,  Graptemys  inomata,   Testudo   brontops,   T.  exornata,  Platypeltis 
leucopotamica. 


Uinta. 


Bacna   emiliae,   Echmatemys  callopyge,    E.    uintensis,    Hadrianus     tumidus, 
Amyda  crassa. 


Bridget. 


Lower. 


D.  ?Echmatemys  septaria  (Washakie),  ? Amyda  egregia 
(Washakie). 

C.  Anosteira  ornata,  Amyda  salebrosa,  Platypeltis 
serialis,    P.  postera. 

B.  Baena  arenosa,  ?B.  clara,  B.  sima,  B.  riparia,Chis- 
tcrnon  undatum,  C .  hebraicum,  Baptemys  wyomin- 
gensis,  ?B.  fluviatilis,  Anosteira  ornata,  Clemmys 
morrisiae,  Echmatemys  wyoiningensis,  E.  haydeni, 
E.  stevensoniana,  ?E.  septaria,  E.  arethusa,  E. 
cyane,  E.  shaughnessiana,  E.  ocyrrhoe,  E.  tcgle, 
E  naomi,  E,  pusilla,  E.  latilabiata,  ?E.  polycypha, 
?E.  terrestris,  Hadrianus  corsoni,  Achilemys 
allabiata,  Plastomenus  thomasi,  P.  visendus,  P. 
tantilluSj  P.  ccdemius,  P.  molopinus,  Aspideretes 
guttatus,  A.  ellipticus,  A.  grangeri,  Amyda  uinta- 
ensis,  A.  scutumantiquum,  A.  ?  concentrica,  A. 
franciscae,  A.?  exquisita,  A.  mira,  A.?  tritor, 
Temnotrionyx  manducans,  Platypeltis  serialis,  P. 
trionychoides,    P.    heteroglypta,    P.    cxtensa. 


Gulf  Region. 
Jackson  epoch. 


Hadrianus  schucherti 


A.  Anosteira  radulina,  Hybemys  arenaria,  Amyda  £equa. 


Wind 
River. 


Baptemys  tricarinata. 


Wasatch. 


Rocky  Mot:NTAiN  Rf.gion. 
Baena  arenosa,  Kallistira  costilata,  Notomorpha  gravis, 
Echmatemys  lativertebralis,  E.  ciboUensis,  E.  me- 
gaulax,  E.  testudinea,  E.  euthneta,  Hadrianus 
niajusculus,  Plastomenus  catenatus,  P.  corrugatus, 
P.  communis,  P.?  Icptomitus,  P.?  lachrymalis,  P.  r 
fractus,  Amyda  cariosa,  A.  radula,  Platypeltis  serialis. 


Easttrn  Region. 
Lerabonax  polerai- 
cus,  L.  insularis, 
L.propylaeus,  Che- 
Ionia  parvitecta, 
Agomphus  oxyster- 
num,  Amyda?  pen- 
nata.  A.?  Virgin- 
ian a  . 


Torrejon. 


Puerco. 


Baena    escavada,  Alamosemys  substricta,    Hoplochelys    saliens,  H.  paludosa, 
Aspideretes  singularis. 


?Hoplochelys    crassa,  Conchochelys  admirabilis,  Aspideretes  sagatus,  A.  puer- 
cencis,  A.?  nassau  (Fort  Union  beds). 


ig  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

In  North  America  no  turtles  are  known  to  have  existed  in  deposits  below  the 
Morrison  beds  of  the  Upper  Jurassic.  Dr.  Edward  Hitchcock  has  indeed  assigned 
to  the  tortoises  certain  tracks  observed  by  him  in  the  Triassic  sandstones  of  Massa- 
chusetts and  Connecticut;  but,  while  there  is  no  improbability  that  turtles  occurred 
there  and  then,  there  is  no  certainty  of  it.  As  is  seen  from  table  i,  2  species  of 
turtles,  both  belonging  to  the  Amphichelydia,  have  been  found  in  the  Morrison  beds 
of  the  Rocky  Mountam  region.  These  beds  are  sometimes  regarded  as  belonging  to 
the  Lower  Cretaceous,  equivalent  to  the  Wealden  of  Europe,  but  it  is  more  probable 
that  they  correspond  to  the  Kimeridge  Clay  or  the  Purbeck  (Fraas,  Zeitschr.  deutch. 
geol.  Gesellsch.,  liii,  1902,  briefl.  Mitth.,  p.  59)  or  even  a  Httle  lower.  So  far  as  now 
known,  no  other  group  than  the  Amphichelydia  are  represented  until  we  reach  the 
Benton,  of  the  Upper  Cretaceous.  In  the  lowest  division  of  this  there  occurs  an 
undoubted  marine  turtle  belonging  to  the  Cryptodira.  A  species  of  Glyptops  is 
found  in  the  Potomac  beds  near  Washington,  District  of  Columbia,  and  another 
species  of  probably  the  same  genus  in  the  Washita  beds  of  Kansas. 

Turtle  remains  are  not  uncommon  in  the  Niobrara  beds  of  Kansas,  but  when  we 
come  to  examine  the  list,  we  find  the  species  not  numerous,  and  they  belong  to  only 
four  genera.  The  species  of  Toxochelys  and  oi  Porthochelys  appear  to  have  hved  in 
the  Niobrara  ocean  near  the  coasts.  The  species  of  Protostega,  on  the  other  hand, 
evidently  ventured  far  out  on  the  high  seas.  Toxochelys  and  Porthochelys  appear  to 
have  continued  on  into  the  Pierre;  Protostega  was  there  replaced  by,  or  transformed 
into,  the  huge  Archelon. 

About  the  middle  of  the  Upper  Cretaceous,  conditions  were  favorable  for  the 
existence  and  the  inhumation  of  many  species  of  turtles.  These  are  found  now  in 
two  widely  removed  regions  and  in  deposits  made  under  widely  different  conditions. 
On  the  Atlantic  border,  especially  in  New  Jersey,  occurs  a  series  of  marine  deposits 
from  which  have  been  derived  about  40  species  of  turtles,  including  9  species 
of  Pleurodira  and  2  species  of  Trionychidae.  The  remainder  are  Cryptodira,  among 
them  many  coast-inhabiting  Thalassemydidae,  all  of  which  were  probably  furnisht 
with  jaws  fitted  for  crushing  hard  mollusks  and  crustaceans.  The  family  of  Dermate- 
mydidae,  represented  now  by  only  3  genera  and  4  species,  appear  in  great  numbers 
and  variety,  especially  in  the  New  Jersey  Cretaceous  greensand.  Whence  this 
assemblage  of  turtles  came  we  have  no  clue.  Scant  remains  indicate  the  existence 
of  two  species  of  large  marine  turtles,  Atlantochelys  and  Neptunochelys. 

In  the  heart  of  the  continent  at  nearly  the  same  time,  possibly  a  little  earlier, 
there  were  being  laid  down  fresh  and  brackish  water  deposits,  now  known  as  the 
Judith  River  beds.  They  are  found  in  Montana  and  British  America,  and  have 
furnisht  about  15  species  of  turtles;  but  these  are  quite  different  from  those  of  the 
Atlantic  coast  deposits  just  mentioned.  There  are,  indeed,  4  or  5  species  of  triony- 
chids  of  the  genus  Aspideretes,  a  genus  Hving  now  in  Asia,  a  species  of  Plastomenus, 
and  3  or  4  species  of  Dermatemydidae;  but  the  latter  belong  to  genera  distinct  from 
those  found  in  the  New  Jersey  deposits.  In  these  Judith  River  beds  reappear  rep- 
resentatives of  the  Amphichelydia,  turtles  which  we  have  found  to  characterize  the 
Upper  Jurassic  and  the  Lower  Cretaceous.  In  America  the  turtles  of  this  group 
appear  generally  to  have  avoided  true  marine  conditions. 

Succeeding  the  Pierre  and  the  Fox  Hills  epochs  came  that  of  the  Laramie.  In 
the  fresh  and  brackish  water  deposits  laid  down  during  this  time  there  were  buried 
remains  of  a  great  variety  of  turtles,  but  unfortunately  these  remains  are  usually 
very  fragmentary;  16  species  are  recognized  as  belonging  here.  Their  relationships 
are  close  to  the  turtles  of  the  Judith  River  beds,  some  species  being  as  yet  undis- 
tinguishable.    The  conditions  under  which  the  two  deposits  were  laid  down  were  so 


GEOLOGICAI,    DISTRIBUTION.  39 

similar  that  there  is  no  wonder  that  the  faunae  did  not  differ  greatly.  In  the  Laramie, 
as  in  the  Judith  River,  there  were  Baenidie  and  Trionychidae.  The  Dermate- 
mydidae  are  represented  by  at  least  one  species,  Bastlemys  stnuosa,  not  greatly 
ditferent  from  B.  variolosa  of  the  Judith  River.  The  Pleurodira  appear  to  be 
represented  by  one  species,  Naiadochclys  ingravata,  from  New  Mexico. 

On  entering  the  1  ertiary  there  is  no  striking  change  in  the  turtle  fauna.  In  the 
Fort  Union,  the  Puerco,  and  the  Torrejon,  there  are  yet  Trionychidae,  Dermate- 
mydidae,  and  Baenidae.  Representatives  of  the  same  famihes  pass  up  into  the 
Wasatch.  Here,  however,  new  elements  enter,  the  Emydidae  and  the  Testudinidae. 
It  is  not  improbable  that  Gyremys  spectabihs  of  the  Judith  River  beds  is  an  emyd, 
but  the  group  is  unmistakably  represented  in  the  Wasatch  by  Echmatemys,  a  genus 
in  some  respects  highly  specialized.  1  he  1  estudinidae  are  represented  by  the 
genus  Hadrianus,  the  oldest-known  genus  of  the  family.  All  these  Wasatch  turtles 
inhabited  either  the  land  or  the  fresh  waters  of  streams. 

In  the  Atlantic  region  we  have  nearly  contemporaneous  deposits;  and  in  them 
we  find  fragmentary  remains  of  a  few  probably  marine  turtles  and  of  Trionychidae. 

The  Wind  River  beds  have  so  far  furnisht  only  a  single  species  of  Baptemys,  and 
the  humerus,  187  mm.  long,  of  a  trionychid. 

The  Bridger  beds  of  Wyoming  are  exceedingly  rich  in  turtle  remains,  as  they 
are  also  in  the  bones  of  crocodiles  and  mammals.  The  Baenidae  were  numerous  in 
species  and  individuals.  Only  2  genera  of  dermatemyds  have  been  found.  Emy- 
didae abounded,  and  Trionychidae  ran  riot.  In  addition  to  these  there  were  a  few 
species  of  Plastomenidae.  All  together,  there  are  50  or  more  species  of  turtles 
described  from  the  Bridger  Eocene.  The  abundance  of  Baenidae  and  especially 
of  the  Trionychidae  shows  that  there  were  numerous  streams  and  lagoons;  and  this 
conclusion  is  confirmed  by  the  presence  of  many  species  of  crocodiles.  1  he  occur- 
rence of  the  great  turtle  Hadrianus  seems  to  indicate  the  proximity  of  dry  land. 

Nearly  all  the  species  of  Bridger  turtles  occur  in  the  lower  portion,  that  known 
as  level  B.  No  turtles  have  yet  been  described  from  the  limestone  bands,  but 
fragmentary  remains  occur  there.  These  bands  appear  to  have  been  laid  down  in 
shallow  lakes. 

So  far  as  known  the  turtles  of  the  Uinta  beds  belong  to  genera  found  in  the 
Bridger  beds.  No  Plastomenidae  have  been  found,  and  the  Baenidae  appear  for  the 
last  time  in  our  calendar. 

During  the  Oligocene  epoch  the  scene,  for  the  student  of  turtles,  shifts  from  the 
sea  shore  and  the  mountain  regions  to  the  Great  Plains.  In  the  lowest  division,  the 
Chadron  or  Titanotherium  beds,  are  found  i  trionychid,  i  dermatemyd,  and 
I  emyd,  silent  witnesses  of  the  presence  of  streams.  On  the  other  hand,  there  were 
numerous  species  of  Testudinidae,  or  dry-land  tortoises,  some  of  which  attained  a 
large  size.  Of  Stylemys  nebrascensis  great  numbers  of  shells  have  been  found  in 
South  Dakota  and  Colorado,  in  the  Brule  clays,  or  Oreodon  beds.  Species  of 
Testiido  were  more  abundant  in  the  same  deposits  in  Colorado.  There  can  be  no 
doubt  that  at  this  time  the  climate  of  the  Plains  region  had  become  arid  and  the 
streams  few.  A  similar  climate  appears  to  have  prevailed  in  the  John  Day  region 
of  Oregon,  where  2  or  3  species  of  Stylemys  abounded,  but,  so  far  as  known,  no 
other  turtles. 

The  Miocene  deposits  of  the  interior  ot  the  continent  are  characterized  by  the 
presence  of  species  of  Testiido,  many  of  them  of  large  size,  resembling  the  gigantic 
tortoises  of  the  Galapagos  Islands.  Sixteen  species  are  described.  In  the  Middle 
Miocene  of  Oregon  there  has  been  found  a  species  of  Clemmys  (C.  saxea);  in  the 
Upper  Miocene  of  Kansas,  Trachemys  hillt.     In  the  Yorktown  beds  of  the  Atlantic 


40  FOSSIL   TURTI.KS    OF    NORTH    AMKRICA. 

Slope  are  found  two  species  of  the  Cheloniidae  and  fragments  of  three  species  of 
Trionychidse.  We  can  not  doubt  that  in  the  streams  of  the  Mississippi  Valley  and 
eastward  there  was  an  abundant  population  of  water-loving  turtles,  but  farther 
westward  this  order  of  reptiles  was   represented  principally  by  the  land  tortoises. 

During  the  Pliocene  the  land  tortoises  continued  to  predominate,  especially  in  the 
interior  region.  Three  species  are  known  from  the  Blanco  beds  of  Texas.  In  deposits 
of  apparently  the  same  age  in  Oregon  there  has  been  found  a  species  of  Clenimys. 

In  the  Peace  Creek  beds  of  Florida,  belonging  apparently  to  the  Upper  Pliocene, 
there  are  found,  with  one  large  Testudo,  numerous  Emydidae  and  a  species  of 
Chelydrida?.  These  are  closely  related  to  species  yet  living  in  that  region.  Among 
the  numerous  turtle  bones  put  in  the  writer's  hands  from  Hillsborough  County, 
Florida,  are  many  fragments  that  evidently  belonged  to  yet  undescribed  species  of 
Emydidae  and  Trionychidae. 

In  the  scattered  deposits  of  the  Pleistocene,  in  which  we  might  expect  to  find 
remains  of  turtles,  we  discover  a  few  species;  and  these  present  a  still  closer  approach 
to  those  now  inhabiting  the  same  territory.  In  what  probably  corresponds  to  the 
Equus,  or  Sheridan,  beds  of  the  region  west  of  the  Mississippi  River  have  been 
discovered  a  species  of  Chrysemys,  3  species  of  Trachemys,  a  species  of  Terrapene, 
and  3  species  of  Testudo.  It  is  worthy  of  note  that  no  Testudo  attains  the  size 
that  was  reacht  by  species  of  the  genus  during  the  Miocene  and  the  whole  of  the 
Pliocene.  In  the  Atlantic  region,  in  caves  and  superficial  deposits,  have  been  found 
remains  of  the  snapping-turtle,  the  sculptured  turtle,  another  supposed  species  of 
Clemmys,  and  one  or  more  species  of  box-tortoises. 

Briefly  let  us  consider  the  geological  history  of  the  turtles  of  other  regions. 

The  earHest  known  turtle  remains  have  been  found  in  the  Middle  Triassic,  the 
Muschelkalk,  of  Germany.  Huene  (Palaeont.  Abhandl.,  x,  1906)  has  described 
a  few  cervical  vertebrse  which  he  regarded  as  probably  having  belonged  to  crypto- 
diran  turtles.  In  the  Upper  Triassic  of  the  same  country,  the  Keuper,  has  been 
found  Proganochelys,  a  nearly  complete  shell  of  which  has  been  described  by  E.  Fraas 
(Jahresh.  Ver.  Naturk.  Wiirrt.,  lv,  1899,  p.  401 ).  The  present  writer  believes  that 
this  turtle  belonged  to  the  Amphichelydia,  and  it  is  probable  that  the  cervical 
vertebrae  from  the  Muschelkalk  belonged  to  some  turtle  of  the  same  group. 

The  next  oldest  known  turtle,  known  only  from  impressions  of  the  carapace  on 
slabs  of  rock,  is  Protochelys  stncklandi,  from  the  Stonesfield  slate,  of  the  Great 
Oolite,  of  Oxfordshire,  England.     It  belongs  probably  to  the  Amphichelydia. 

In  contrast  to  the  scanty  chelonian  population  of  the  North  American  Upper 
Jurassic,  that  of  Europe  was  extremely  numerous.  From  the  Jurassic  at  Solothurn, 
Switzerland,  about  15  species  have  been  described.  From  deposits  of  approxi- 
mately the  same  age  in  Germany,  France,  and  England,  numerous  other  species 
-have  been  reported.  Many  of  the  species  have  come  from  the  Kimeridge,  of  the 
upper  portion  of  the  Great  Oolite,  a  formation  found  in  England,  France,  and 
Germany,  and  belonging  near  the  level  of  the  Morrison  beds  of  Wyoming,  as 
already  stated.  The  principal  genera  described  from  the  Upper  Jurassic  of  Europe 
are  Pleurosternon,  Platychelys,  Plesiochelys,  Idiochelys,  Hydropelta,  Parachelys, 
Acichelys,  Thalassemys,  Stegochelys,  and  Tropodemys.  The  first  two  belong 
without  doubt  to  the  Amphichelydia,  Pleurosternon  being  closely  related  to  Glyptops 
and  Platychelys  to  Prohaena.  Craspedochelys  and  Plesiochelys  are  almost  certainly 
not  Pleurodira  and  may  be  referred  provisionally  to  the  Amphichelydia.  The 
other  genera  are  to  be  referred  to  the  Thalassemydidae,  a  family  of  Cryptodira. 
Similar  turtles  are  found  a  little  higher  up  in  the  European  Jurassic,  in  the  Purbeck 


GEOLOGICAI,    DlSTRlliUTION.  4I 

and  Portlandian;  likewise,  in  the  Wealden,  of  the  Lower  Cretaceous  deposits  of 
approximately  the  age  of  the  Trinity  and  Potomac.  In  the  Portlandian  is  found  a 
species  of  Pleurosternon.  In  the  Wealden  occurs  the  genus  Tretosternon,  which 
may  have  given  origin  to  the  Dermatemydidae. 

In  the  Gault,  at  the  base  of  the  Upper  Cretaceous  of  England,  have  been  found 
remains  of  a  large  turtle  which  is  called  by  Lydekker  Chelone  jessoni  (Quart.  Jour. 
Geol.  Soc,  XLV,  1889,  p.  231).  While  it  is  possible  that  this  species  belonged  to  the 
Chelonidae,  it  is  improbable  that  it  was  congeneric  with  our  living  green-turtle.  It 
would  be  more  proper  to  call  it  Cimochelys  jessoni . 

The  Cambridge  Greensand,  of  the  Cenomanian,  near  the  time  of  the  American 
Dakota  or  Benton,  furnishes  a  number  of  turtles.  These  are  represented  by  skulls 
alone  and  are  placed  m  the  genus  Rhtnochelys.  Their  affinities  are  uncertain,  but 
they  are  neither  Pleurodira  nor  Trionychoidea.  The  genus  seems  not  to  be  repre- 
sented in  America. 

In  the  Lower  Chalk,  Turonian,  of  Kent,  England,  are  found  remains  which  are 
assigned  by  Lydekker  (Cat.  Chelonians,  1889,  p.  34)  to  Chelone  benstedi.  For  the 
reason  noted  above,  this  species  ought  to  be  called  Cwiochelys  benstedi,  as  it  was 
named  by  Owen.  The  Turonian  was  deposited  approximately  at  the  time  of  our 
Niobrara  beds. 

In  the  Upper  Cretaceous  of  England  and  the  continent  is  found  a  huge  marine 
turtle,  Allopleuron  hoffmani;  its  costals  are  greatly  reduced.  In  Italy  has  been 
found  another  large  sea-turtle,  Protosphargis,  reminding  us  of  Protostega  and 
Archelon,  of  the  American  Upper  Cretaceous. 

In  the  Upper  Cretaceous  of  Provence,  France,  has  been  discovered  the  remark- 
able turtle,  Polysternon.  Besides  mesoplastra  it  possesses  a  pair  of  bones  between 
the  hypoplastra  and  the  xiphiplastra,  and  the  pelvic  bones  are  sutured  to  the  xiphi- 
plastra.  It  is  regarded  as  a  pleurodire;  and  it  appeared  about  the  time  that  this 
group  presented  itself  in  America. 

During  the  Tertiary  period  the  history  of  European  turtles  appears  to  have  run 
on  much  as  it  did  in  America,  altho  in  each  country  the  history  had  its  peculiar 
features.  Osborn  (Ann.  N.  Y.  Acad.  Sci.,  xiii,  1890,  p.  7)  finds  that  America  and 
Europe  had  a  similar  mammalian  fauna  throughout  the  Lower  Eocene,  but  that 
there  followed  a  Middle  and  Upper  Eocene  interval  of  faunal  separation  of  the  two 
countries;  while  again  there  was  an  approach,  from  the  beginning  of  the  Oligocene 
onward  until  the  late  Pleistocene.  With  respect  to  the  turtles  it  may  be  said  that 
the  two  regions  were  farther  apart  at  the  beginning  of  the  Eocene,  converged  to 
perhaps  the  middle  of  the  Pliocene,  then  diverged. 

In  the  London  Clay  of  England  is  found  Eosphargis,  the  earliest  representative 
of  the  Athecae.  In  Belgium  at  the  same  time  there  existed  Pseudotrionyx,  a  relative 
of  the  living  Carettochelys.  In  England  there  were  yet  two  species  of  Pleurodires. 
So  far  as  known,  the  group  was  not  represented  at  the  time  in  America.  In  Europe 
there  were  no  Amphichelydia,  no  Dermatemydidae,  no  known  species  of  Plasto- 
menidae,  and  no  Trionychidae.  The  species  of  Argillochelys  may  belong  to  the 
Cheloniidae.  Species  referred  by  Lydekker  to  Chrysemys  represent  the  Wasatch 
Emydidae,  while  Homopus  comptoni  represents  Hadrianus. 

The  Middle  Eocene  of  Europe  witnest  a  great  multiplication  in  the  number  of 
Trionychid,-e.  Species  referred  to  the  yet  living  Asiatic  genus  Ocadia,  of  the 
Emydidae,  resembled  the  Bridger  genus  Echmatemys.  The  Bridger  epoch  differs 
from  the  European  Eocene  in  its  numerous  species  of  Baenidae. 

During  the  Oligocene,  Europe  possest  numerous  Trionychidae.  Doubtless  in 
America,  too,  they  existed  in  numbers,  but  they  have  mostly  escaped  preservation. 


42  FOSSIL   TURTLES    OK    NORTH    AMERICA. 

America  at  that  time  yet  harbored  Dermatemydidae;  while  Europe  gave  asylum  to 
Chelydridae  and  to  the  pecuHar  genus  Ptychogaster. 

During  the  Miocene,  land  tortoises,  Testudinidae,  abounded  in  both  America 
and  Europe,  turtles  especially  characteristic  of  dry  lands.  Europe  possest  various 
genera  of  Emydidae  and  species  of  Chelydra,  a  genus  now  found  only  in  North 
America,  but  apparently  a  late  immigrant  thither. 

There  are  evidences  that  during  the  PHocene  the  turtle  population  of  Europe 
diminisht  in  genera,  species,  and  probably  in  individuals.  Trionychidje  were  still 
found  in  Italy,  but  are  not  known  after  this  time  in  Europe. 

An  interesting  region  for  the  student  of  chelonians  is  found  in  India.  Here 
numerous  species  of  i  rionychidae,  Emydidae,  and  Testudinidae  have  been  exhumed 
from  late  Tertiary;  but  most  of  the  forms  appear  to  belong  to  existing  genera. 

From  the  Upper  Eocene  fluviomarine  beds  of  the  Fayum  of  Egypt  we  have 
recently  secured  a  most  interesting  and  instructive  addition  to  our  knowledge  of 
the  turtles  of  that  time,  Dr.  C.  W.  Andrews  having  described  9  species  from  those 
beds.  One  of  these  is  a  species  of  Psephophoriis,  related  to  Dermochelys.  Of 
Testudo  there  are  3  species,  a  shell  of  one  of  which  had  a  length  of  1500  mm.  A 
portion  of  the  skull  of  a  supposed  species  of  Thalassochelys  is  also  described.  Of 
Podocnemis  there  are  2  species.  Besides  these,  a  new  genus  of  Pleurodira,  Ste- 
reogenys,  with  remarkable  characters,  is  made  known  to  us. 

We  must  not  omit  to  mention  that  remarkable  Pleurodiran  turtle,  Miolania, 
which  was  originally  described  from  remains  found  in  Pleistocene  deposits  on 
Lord  Howe  Island,  east  of  Australia.  A  second  species  was  afterward  discovered 
in  Queensland,  Austraha;  and  more  recently  Dr.  A.  S.  Woodward  has  described 
a  third  species  from  northern  Patagonia.  Outside  the  remarkable  structure  of 
this  turtle,  it  becomes  interesting  for  the  reason  that  its  presence  in  the  regions 
named  appears  to  confirm  the  theory  that  there  was  once  land  connection  between 
Australia  and  South  America. 


DESCRIPTION    OF    GROUPS    AND    SPECIES.  43 

DESCRIPTION  OF  GROUPS  AND  SPECIES. 

Order  TESTUDINES  Batsch.     Turtles  and  Tortoises. 

Reptiles  with  the  body  relatively  short  and  broad.  Quadrate  bone  immovably  joined  to  the 
pterygoid,  the  prootic,  and  paroccipital;  its  outer  surface  excavated  to  form  a  tympanic  cavity. 
Paroccipitals  not  consolidated  with  the  exoccipital.  Vomer  single,  if  not  missing.  Pterygoids 
closing  the  palate  by  their  inner  borders.  Teeth  never  present;  the  jaws  always  armed  with  a 
horny  covering.  Nasal  opening  single.  Dorsal  ribs  each  with  a  single  head;  at  least  the  anterior 
ones  intervertebrally  attacht.  A  nuchal  bone  always  present.  Cervical  vertebrae  eight;  dorsals 
ten.  Epiplastra  (clavicles)  and  at  least  six  other  bones  present  in  the  abdominal  wall.  No 
sternum  or  sternal  ribs  ever  developt.  Each  half  of  the  pelvis  composed  of  three  bones,  all  con- 
tributing to  the  acetabulum.  Four  limbs  always  present.   Humerus  with  ectepicondylar  passage. 

Thi.s  order  of  Reptilia  is  divided  into  two  suborders,  the  Athec.^':  and  the 
Thecophora. 

Suborder  ATHECffi  Cope. 

Turtles  which  retain  the  primitive  dermal  armor,  with  at  least  traces  of  the  suhdermai 
expansions  connected  with  the  ribs. 

Of  this  suborder  there  is  no  known  representative  from  North  American 
deposits,  unless  possibly  certain  dermal  bones  that  have  been  found  to  accompany 
the  remains  of  Bastlosaurus  (Zeuglodon)  belonged  to  some  otherwise  unknown 
species  of  the  group.  This  is  improbable,  however,  as  shown  by  Dames  (Pal. 
Abhandl.,  v,  1894,  p.  220).  In  Europe  the  suborder  is  represented  by  Eosphargis, 
of  the  London  Clay  of  England,  by  P.r^/)/!o/?/!or«.f,  of  the  Oligocene  and  Miocene  of 
the  Continent,  and  perhaps  by  Pseudosphargis,  of  the  Upper  Oligocene  of  Germany. 
The  latter  genus  is  based  on  a  very  imperfect  skull;  and,  while  presenting  many 
resemblances  to  Dermochelys,  is  not  regarded  by  the  present  writer  as  being  at  all 
certainly  a  member  of  the  Athecae.  This  turtle  possest  descending  plates  from  the 
parietals  to  the  pterygoids. 

Suborder  THECOPHORA  DoUo. 

Turtles  in  which  the  primitive  dermal  armor  has  become  obsolete  or  abolisht.  Always  a 
more  or  less  complete  carapace  formed  by  at  least  the  expansions  of  the  ribs,  the  nuchal  bone 
and  with  rare  exceptions  a  series  of  neurals;  usually  a  very  complete  shell  formed  by  the  bones 
mentioned,  together  with  series  of  peripherals  and  a  varying  number  of  plastral  bones.  Skull 
always  furnisht  with  descending  parietal  plates. 

This  suborder,  containing  the  vast  majority  of  turtles,  living  and  extinct, 
consists  of  four  superfamiHes,  the  Amphichelydia,  the  Pi.eurodira,  the  Crypto- 
DIRA,  and  the  Trionychoidea.     Of  the  first  there  are  no  living  representatives. 

Key  to  Superfamilies  of  Thecophora. 

1.  Mesoplastra  present  or  absent.      If  absent,  hinder  lobe  of  plastron  with  rough  scars  for  union  with 

pelvic  bones  except  in  Plesiochelyidse. 

a'.  Mesoplastra  always,  so  far  as  known,  present;   no  plastral  scars Amphichelydia 

c?.  Mesolpastra  present  or  absent;    rough  scars  on  hinder  lobe  of  plastron Pleurodira 

2.  Mesoplastra  always  absent;    no  sutural  scars  on  plastron. 

n'.   Peripheral    bones  always  present Cryptodira 


ea 


a  .   Peripheral  bones  present  only  in  one  gtnus  now  existing Trionychoidi 

SuperfamUy  AMPHICHELYDIA  Lydelcker. 

Thecophorous  turtles  having  a  carapace  composed  of  neural,  costal,  and  peripheral  bones 
and  a  plastron  in  which  the  epiplastra  are  in  contact  with  the  hyoplastra.  Mesoplastra  usually, 
perhaps  always,  present.     Intergular  and  inframarginal  scutes  probably  always   developt. 


44  KOSSir,   TURTI.KS    OK    NORTH    AMERICA. 

Skull  essentially  crvptodiran  in  stiuctuie,  but  with  various  primitive  elements.     Neck  short, 
the  vertebrae  little  differentiated.    Limbs,  so  far  as  known,  fitted  for  walking. 

This  group  was  establisht  by  Mr.  Richard  Lydekker,  to  include,  as  he  states, 
a  number  of  generalized  late  Mesozoic  forms  which  may  be  regarded  as  allied  to  the 
earlier  (and  then  unknown)  progenitors  of  the  Pleurodira  and  Cryptodira.  He 
characterized  them  as  having  a  shell  constructed  on  the  plan  of  that  of  the  Crypto- 
dira and  Pleurodira,  in  which  mesoplastral  bones  and  an  intergular  shield  are 
developt.  The  pubis  may  articulate,  without  sutural  union,  with  the  xiphiplastron. 
At  the  time  he  wrote  the  skull  and  neck  were  not  known.  The  coracoid  and  the 
humerus  were  regarded  as  being  ot  the  pleurodiran  type.  The  genera  included 
were  Pleurosternou,  Baena,  and  Platychelys.  (Lydekker,  Cat.  Foss.  Rept.  Brit. 
Mus.,  pt.  Ill,  1889,  p.  204.) 

In  1890  (Amer.  Naturalist,  xxiv,  p.  530)  and  1891  (Proc.  Acad.  Nat.  Sci.  Phila., 
p.  411)  Dr.  George  Baur,  working  on  materials  at  Yale  University,  added  greatly 
to  the  knowledge  of  the  group,  regarded  by  him  as  a  suborder.  He  likewise  furnisht 
a  definition  of  the  group.  Ihe  present  writer  (Bull.  Amer.  Mus.  Nat.  Hist.,  xxi, 
1905,  p.  137),  having  studied  well-preserved  remains  of  Baena  from  the  Bridger 
beds,  was  enabled  to  make  further  additions  to  our  knowledge  of  the  Amphichelydia 
and  to  correct  some  of  Dr.  Baur's  statements  and  generalizations. 

In  this  superfamily  the  plastron  appears  to  be  in  all  cases  more  or  less  closely 
joined  to  the  carapace  by  sutural  union  with  the  peripherals,  and  in  the  Baenid:e 
the  union  is  strengthened  by  powerful  axillary  and  inguinal  buttresses.  In  all 
forms  known  to  belong  to  the  group  there  are  well-developt  mesoplastra;  but  since 
these  bones  have  been  abolisht  from  the  plastron  of  all  the  Cryptodira  and  from 
thatof  most  of  the  Pleurodira,  there  seems  to  be  no  good  reason  to  suppose  that  they 
might  not  have  been  supprest  in  the  case  of  some  of  the  Amphichelydia.  Accord- 
ingly the  writer  has  ventured  (Bull.  Amer.  Mus.  Nat.  Hist.,  xxi,  pp.  144,  167)  to 
include  provisionally  in  the  superfamily  the  Plesiochelyidae.  Nothing  is  known 
certainly  of  the  members  of  the  family  except  the  shells. 

On  the  carapace  of  the  Amphichelydia,  besides  the  scutes  found  in  such  turtles 
as  the  F^mydidae,  there  may  occur  supernumerary  vertebrals,  costals,  and  supra- 
marginals.  On  the  plastron  there  are,  in  all  known  cases,  intergulars  and  full  series 
of  intramarginals.  The  boundaries  between  the  scutes  are  liable  to  vary  in  their 
positions.  T  he  sulcus  between  the  paired  scutes  of  the  plastron  especially  is  often 
found  wandering  far  from  the  midline.  It  is  as  if  the  limits  of  the  scutes  had  not 
m  these  early  forms  yet  become  firmly  establisht.  In  the  skull  there  are  such  primi- 
tive elements  as  distinct  nasals  and  lacrimals.  The  temporal  region  is  always 
covered  over  and  the  quadrates  are  notcht  for  the  passage  of  the  stapedial  rod. 
The  pterygoids  never  have  the  wing-like  expansions  that  characterize  the  Pleuro- 
dira; and,  unHke  the  latter,  the  pterygoids  push  themselves  backward  between  the 
quadrates  and  the  basioccipital  and  the  basisphenoid. 

The  cervical  vertebrae  may,  as  in  Glyptops,  be  all  bicoelous,  or,  as  in  the  Baenida?, 
one  end  of  most  of  them  may  be  convex.  The  neck  was  short  and  the  differentiation 
of  the  cervicals  had  progrest  so  little  that  probably  these  turtles  could  protect  their 
heads  neither  by  withdrawing  them  within  the  shells  as  do  the  Emydidae,  nor  by 
laying  them  on  one  side  beneath  the  front  border  of  the  carapace  after  the  manner 
of  the  Pleurodira. 

In  the  Pleurosternidae  and  the  Baenidae,  whose  limbs  are  now  known,  these  were 
fitted  for  progression  on  land.  Doubtless  they  were  inhabitants  of  the  waters  of 
lakes  and  rivers  and  were  good  swimmers,  but  there  was  no  special  modification  of 
the  limbs  for  swimmine. 


PLEUROSTERNID^.  45 

In  addition  to  the  families  Pleiirosternida;  and  Baenidae  here  treated,  and  the 
Plesiochelyidae  provisionally  included,  the  writer  refers  to  this  superfamily  with- 
out hesitation  the  Triassic  genus  Proganochelys,  which  has  recently  been  so  well 
described  by  Dr.  K.  Fraas.  Without  doubt  this  genus  forms  the  type  of  a  distinct 
family,  the  ProganochelyidtP,  characterized  by  the  broad  shell,  the  hmder  border  of 
which  is  deeply  scallopt,  by  the  extremely  broad  vertebral  scutes,  by  the  series  of 
supramarginal  scutes  in  front  of  the  first  costals  and  behind  the  last  ones,  and  by 
the  mesoplastra,  which  meet  at  the  midline  and  are  enormously  expanded  at  their 
outer  ends.  The  genus  Proganochelys  is  the  oldest  turtle  of  which  we  have  any 
considerable  knowledge,  coming  as  it  does  from  the  Keuper,  of  the  Trias.  Cervical 
vertebnc  of  a  genus  named  Chelyzoon  have  been  described  by  Huene  from  the 
Muschelkalk  of  Germany.  They  have  been  supposed  to  belong  to  the  Cryptodira, 
but  there  is  little  reason  why  they  should  not  be  referred  to  the  Amphichelydia. 

The  most  recent  certainly  known  member  of  this  subfamily  comes  to  us  from  the 
Uinta  beds  of  Utah.  Pleurosternon  mioccenuni  Portis  has  been  described  from  the 
Tertiary  near  Lausanne,  Switzerland,  but  it  is  based  on  a  badly  damaged  plastron. 

1.  Axillary  and  inguinal  buttresses  feebly  developt.     Plastron  usually  not  notcbt  behind; 

nusopla.stra  usually  not  narrowed  at  midline PleurosterntJrc 

2.  Axillary  and  inguinal  buttresses  strongly  developt;  mesoplastra  narrowing  toward  midline.  .   Ba'enidte 

Family  PLEUROSTERNID^  Cope. 

A  family  of  Amphichelydia.  Carapace  with  costals  articulated  to  the  peripherals  by  close 
sutures  and  by  gomphosis  of  ends  of  ribs.  Plastron  joined  to  the  carapace  by  sutures  and  by 
narrow  axillary  and  inguinal  buttresses;  the  former  ascending  to  the  first  costal,  the  latter 
attaining  the  borders  of  the  fifth  and  sixth  costals  at  their  junction.  In  Helochelys  the  union  of 
carapace  and  plastron  probably  less  intimate.  Mesoplastrals  meeting  broadly  at  the  midline, 
not  much  expanded  toward  the  outer  ends.  Exposed  surfaces  of  carapace  and  plastron  tuber- 
culated  or  shagreened.  Intergulars  and  inframarginals  present.  Skull  elongated  and  pointed; 
the  bones  mostly  finely  tuberculated.  The  cervical  vertebrae  are  biconcave.  Coracoids 
distally  expanded. 

So  far  as  the  writer  knows,  the  name  Pleurosternid:e  for  this  family  was  proposed 
by  Prof.  E.  D.  Cope  in  1868  (Proc.  Acad.  Nat.  Sci.  Phila.,  p.  282)  andwas  employed 
by  him  at  various  times  afterward.  He  regarded  it  as  a  family  distinct  from  the 
BaenidiB.  Both  families  appear  to  have  been  always  included  by  him  among  the 
Cryptodira.  Lydekker  (Cat.  Foss.  Reptilia,  iii,  p.  205)  includes  in  it  the  Baenidae. 
Baur  (Proc.  Acad.  Nat.  Sci.  Phila.  i8gi,  p.  428)  thinks  it  better  to  leave  i5af«a  in  a 
distinct  family,  nearly  related  to  Pleurosternon.  To  the  present  writer  each  group 
appears  to  be  worthy  of  family  rank.  The  genus  Helochelys,  of  the  Cenomanian  of 
Germany,  evidently  belongs  with  the  Pleurosternidae.  Pleurosternon  is  found  in  the 
Purbeck  and  Portland  Oolite  of  England.  A  species  described  by  Roemer  as 
Emys  menkei,  from  the  Wealden  of  Germany,  is  believed  to  belong  to  Pleuro- 
sternon. Portis  has  described  P.  mioccFnuiii  from  the  Tertiary  near  Lausanne, 
Switzerland.  Li  our  own  country,  it  appears  that  Glyptops  existed  from  the 
Upper  Jurassic  through  the  Lower  Cretaceous  {G.  ccelatus)  and  the  Benton  {G. 
pervicax)  into  the  Denver  {G.  deprcssus)  of  the  uppermost  Cretaceous. 

Genus  GLYPTOPS  Marsh. 

Carapace  deprest.  Exposed  surfaces  of  the  shell  rough  with  small  tubercles  and  twisted 
ridges.  Neurals  hexagonal,  with  the  broad  end  m  front.  Costo-marginal  sulci  mostly  below 
the  costo-peripheral  sutures.  Axillary  buttresses  reaching  border  of  first  costals.  Inguinal 
buttresses  each  entering  an  excavation  at  lower  borders  of  fifth  and  sixth  costals.    Mesoplas- 


46  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

trals  joining  extensively  at  the  midline.  Bridge  about  twice  as  broad  as  long.  Inframarginals 
almost  wholly  on  the  plastral  bones.  Plastron  with  hinder  lobe  not  shortened  and  not  notcht 
behind.  Pelvis  not  suturally  articulated  with  the  plastral  bones.  Skull  pointed  anteriorly; 
most  of  its  surface  bones  finely  tuberculated.  Bones  of  lower  jaw  smooth;  the  symphysis 
short. 

This  genus  was  establisht  by  Professor  Marsh  in  the  year  1890  (Amer.  Jour. 
Sci.,  XL,  p.  177),  his  type  being  G.  ornatus,  collected  in  the  Upper  Jurassic  of 
Wyoming.  This  species  is  apparently  identical  with  Cope's  Compsemys  plicatulus. 
A  comparison  of  specimens  of  Compsemys  victus  Leidy  with  Cope's  species  just 
mentioned  makes  it  certain  that  the  two  forms  are  not  congeneric.  Compsemys 
plicatulus  must  therefore  be  removed  from  Compsemys,  and  Marsh's  genus  Glyptops 
becomes  available.  The  assignment  by  Cope  of  various  species  of  Jurassic  and 
Cretaceous  turtles  to  Compsemys  was  evidently  due  principally  to  supposed  resem- 
blances in  the  sculpture;  but  all  of  these  species,  except  the  type,  C.  victa,  must  be 
referred  to  other  genera.  There  are  no  evidences  that  C.  victa  possest  mesoplas- 
tra.  The  total  absence  of  distal  prolongations  of  the  costals  for  insertion  in  the 
peripherals  of  C.  victa  and  their  presence  in  G.  plicatulus  sufficiently  separate  them 
genetically. 

To  Glyptops  is  provisionally  referred  G.  pervicax,  which  in  some  respects 
approaches  more  closely  Pleurosternon,  more  especially  in  having  the  plastron 
slightly  notcht  behind.  On  the  other  hand,  the  bridge  is  longer  than  in  Glyptops 
plicatulus.     It  is  not  improbable  that  it  represents  an  undescribed  genus. 

It  is  to  be  noted  that  usually  when  authors  have  referred  to  the  genus  Compsemys 
they  have  had  in  mind  the  species  C.  plicatulus,  because  its  characters  were  well 
known  through  Professor  Marsh's  and  Dr.  Baur's  descriptions;  whereas,  little  is 
even  now  known  about  C.  victa.  For  these  references  the  writer's  Bibliography  and 
Catalogue  of  the  Fossil  Vertebrata  of  North  America,  1902,  p.  437,  may  be  consulted. 

As  here  employed,  Glyptops  will  include  4  species :  the  type,  G.  plicatulus  of  the 
Jurassic,  G.  ccelatus  of  the  Lower  Cretaceous,  G.  pervicax  of  the  Benton,  and 
G.  depress  us  of  the  uppermost  Cretaceous.  Possibly  when  more  is  known  of  the  two 
last-mentioned  species  they  will  be  removed  from  the  genus. 

Glyptops  is  closely  related  to  Pleurosternon  Owen,  as  already  recognized  by 
Dr.  Baur.  However,  it  differs  from  the  latter  in  having  the  hinder  lobe  of  the 
plastron  less  constricted  and  without  posterior  notch,  in  having  the  inframarginals 
almost  wholly  on  the  plastral  bones,  in  having  the  costo-marginal  sulci  well  below 
the  costo-peripheral  sutures,  except  over  the  bridges,  and  in  having  longer  bridges. 
The  distance  from  a  line  joining  the  free  border  of  the  anterior  lobe  of  the  plastron 
with  the  posterior  lobe  to  the  outer  end  of  the  mesoplastron  is  contained  in  the  width 
of  the  bridge  about  three  times  in  Pleurosternon  and  about  two  times  in  Glyptops. 

Helochelys  is  another  relative  of  Glyptops.  Its  hinder  plastral  lobe  is  little  more 
than  half  as  long  as  wide;  the  plastron  appears  to  have  been  less  closely  joined  to 
the  carapace  than  in  Glyptops;  the  bridges  are  short;  and  the  last  neural,  the  only 
one  known,  is  hexagonal,  with  the  broader  end  directed  backward. 

Key  to  the  Known  Species. 
A.  Jurassic. 

a.  Morrison    beds plicatulus 

AA.  Cretaceous. 

a.  Lower  Cretaceous. 

h.   Potomac    beds cctlatus 

hb.   Benton    beds pervicax 

aa.  Upper  Cretaceous. 

c.   Denver    beds  ? Jepressus 


PLEUROSTERNID^.  47 

Glyptops  plicatulus  (Cope). 
Plates  5,  6;   text-figs.  17-27. 

Com psemys  plicatulus,  Cope,  Proc.  Amer.  Philos.  Soc,  xvii,  1877,  p.  196. — Baur,  .Amer.  Naturalist, 
XXIV,  1890,  p.  534;  Proc.  Acad.  Nat.  Sci.  Phila.  1891,  p.  411 ;  Anat.  Anzeiger,  xii,  1896,  p.  565. — 
Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  437. 

Glyptops  ornatus.  Marsh,  Amer.  Jour.  Sci.  (3),  XL,  1890,  p.  177,  pi.  vii,  figs,  i,  2;  Monogr.  U.  S. 
Geol.  Surv.,  xxvii,  1897,  p.  507,  figs.  63,  64. 

The  present  species  is  one  ot  the  two  oldest  known  from  North  America,  coming  as  it  does 
from  the  uppermost  Jurassic.  The  other  species  which  comes  from  the  same  deposits  is 
Probaena  sculpta,  but  it  is  represented  by  only  an  imperfect  shell;  whereas  Glyptops  plicatulus 
is  represented  by  nearly  all  portions  of  the  skeleton. 

The  species  had  for  its  type  various  fragments  that  had  been  collected  for  Professor  Cope 
by  Mr.  O.  W.  Lucas,  at  Canyon  City,  Colorado,  from  freshwater  deposits  that  were  called  by 
Professor  Marsh  the  Atlantosaurus  beds,  by  Scott  and  Knight  the  Como  beds,  and  by  Whitman 
Cross  the  Morrison  beds.  Cope's  type  is  No.  6099  of  the  American  Museum  of  Natural 
History.  The  principal  parts  present  are  one  complete  costal,  apparently  the  third  of  the  left 
side  (plate  5,  fig.  i),  the  proximal  end  of  what  is  regarded  as  the  fifth  of  the  right  side,  the  right 
axillary  region,  most  of  the  left  hypoplastron,  and  a  part  of  the  contiguous  left  xiphiplastron. 
The  supposed  third  costal  is  shorter  than  the  corresponding  one  of  the  American  Museum 
specimen,  No.  336,  a  slightly  smaller  individual,  as  shown  by  the  hypoplastra.  It  might  be 
regarded  as  the  fifth  were  it  not  that  the  distal  end  is  crost  by  the  costo-marginal  sulcus.  The 
vertebral  scutes  are  narrower  than  those  of  No.  336.  Also  the  bases  of  the  rib-heads  are 
slenderer.  The  hypoplastral  is  somewhat  longer  and  at  the  same  time  slightly  narrower  than 
that  of  No.  336.  There  is  a  possibility  that  we  have  here  two  species.  The  sculpture  appears 
to  be  identical  in  the  two  specimens.  Baur  appears  to  have  examined  the  type  bones  and  he 
identified  them  as  being  the  same  as  Marsh's  Glyptops  ornatus. 

Professor  Marsh's  types  of  his  Glyptops  ornatus  were  obtained  at  Como,  Wyoming,  from 
deposits  regarded  as  of  the  same  age  as  those  of  Canyon  City.  The  remains  consisted  of  a 
skull  nearly  complete,  portions  of  two  other  skulls,  and  portions  of  the  shells  of  two  or  three 
other  individuals.  These  were  briefly  described  and  figured  by  Marsh,  as  cited  above.  The 
figure  of  the  skull  particularly  is  very  poor.  This  skull  had  been  crusht  laterally  and  hence 
the  figure  shows  it  as  narrower  than  it  was  in  life.  A  side  view  of  the  same  skull,  prepared  for 
the  U.  S.  Geological  Survey,  by  F.  Berger,  is  here  presented  (plate  5,  fig.  2).  In  1891  Dr. 
Baur,  as  cited,  publisht  a  more  extended  description  of  Marsh's  specimens  and  criticized  some 
of  Marsh's  statements.  The  writer  has  examined  the  skull  figured  by  Marsh.  The  occipital 
condyle  is  broken  away.  The  length  from  the  condyle  to  the  tip  of  the  snout  was  close  to 
62  mm.  The  temporal  region  was  originally  rooft  over  to  a  perpendicular  plane  passing 
through  the  articulations  of  the  quadrate  for  the  lower  jaw.  The  extent  of  this  roof  from  the 
orbits  was  38  mm.  The  median  suture  may  be  traced  from  the  tip  of  the  snout  to  near  the  rear 
of  the  skull.  Most  of  the  other  sutures  are  invisible.  The  supraoccipital  spine  appears  to  have 
been  destroyed.  The  orbit  is  circular,  with  a  diameter  of  12  mm.  The  nasals  are  distinctly 
separated  from  the  prefrontals  and  have  a  length  of  4  mm.  The  premaxillae  are  small  and 
distinct  from  each  other  and  from  the  maxillae.  What  bone  forms  the  septum  between  the  orbit 
and  the  nasal  cavity  can  not  be  determined.  The  maxilla  has  a  thin  cutting-edge  and  a  narrow 
triturating  surface.  This  bone  extends  far  behind  the  orbit  and  has  a  length  of  33  mm.  From 
its  hinder  end  the  suture  between  it  and  the  jugal  may  be  traced  upward  and  forward  to  the 
border  of  the  orbit. 

On  the  lower  side  of  the  skull  is  seen  the  anterior  end  of  the  vomer;  the  remainder  is 
broken  away.  The  choanae  were  placed  far  forward.  The  palatines  ran  forward  nearly  to  a 
line  joining  the  fronts  of  the  orbits.  The  pterygoids  are  interposed  between  the  quadrates 
and  the  basioccipital.  Where  narrowest  the  pterygoid  portion  of  the  palate  is  1 1  mm.  wide. 
The  articulation  of  the  quadrate  for  the  lower  jaw  is  concave  in  all  directions,  most  so  from 
side  to  side. 

In  the  American  Museum  of  Natural  History  there  is  a  specimen  of  this  species  that  was 
collected  at  Bone  Cabin  quarry,  Wyoming,  about  10  miles  from  Como,  the  locality  of  Marsh's 


48 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


specimens  just  mentioned.  The  number  of  the  specimen  is  336.  It  presents  the  shell  complete, 
the  dorsal  and  the  cervical  vertebrae,  the  skull  quite  complete,  the  shoulder  and  pelvic  girdles, 
and  portions  of  all  the  limbs.    The  skull  will  be  described  first. 

When  buried  the  skull  was  undoubtedly  complete,  but  has  suffered  somewhat  during 
disinterment  and  preparation  (plate  5,  figs.  3,  4).  The  bone  is  extremely  brittle  and  much 
fractured.    On  this  account,  and  because  ot  the  roughness  of  the  surface,  the  sutures  are  mostly 

undeterminable.  The  length  from  the  occipital 
condyle  to  the  end  of  the  snout  is  66  mm.,  nearly 
the  same  as  that  ot  Marsh's  specimen.  In  form  it 
is  wedge-shaped,  but  not  so  narrow  as  Marsh's 
laterally  crusht  specimen.  The  width  at  the 
quadrates  is  48  mm.  The  supraoccipital  spine  is 
missing.  It  is  doubtful  whether  it  ever  had  any 
considerable  length.  The  parietals  lack  about  5 
mm.  of  extending  backward  as  far  as  the  occipital 
condyle.  The  roofing  of  the  temporal  region  is 
like  that  of  the  skull  just  described.  Whether  or 
not  the  parietals  join  the  squamosals  can  not  be 
determined;  they  probably  do.  The  orbits  had  a 
diameter  of  15  mm.,  but  some  allowance  must 
be  made  for  distortion;  they  appear  to  have 
been  larger  than  those  of  Marsh's  type.  The 
interorbital  space  measures  9  mm.  Apparently 
the  sutures  bounding  the  frontals  laterally  can  be 
distinguisht,  and  possibly  those  limiting  these 
bones  anteriorly.  Nasal  bones  can  not  be  distin- 
guisht. The  maxillary  bone  is  only  3  mm.  wide 
below  the  orbit.  The  tympanic  cavity  appears  to 
have  been  small.  The  stapedial  passage  was  open 
behind.  The  quadrates  appear  to  have  been 
directed  slightly  forward.  The  lateral  squamosal 
processes  extend  behind  the  occipital  condyle 
about  5  mm. 

On  the  upper  surface  there  is  observed  on 
each  side  a  groove,  or  sulcus,  which  starts  about  8 
mm.  from  the  midline  at  the  hinder  border  of  the 
temporal  roof,  runs  first  forward  and  inward  to 
near  the  midline,  then  toward  the  orbit.  Similar 
sulci  are  seen  in  Chelydra  and  it  is  thus  rendered 
probable  that  the  surface  of  the  head  was  covered 
with  horny  scutes. 

The   basioccipital  and  the   basisphenoid  are 
narrow.    The  suture  between  the  two  can  not  be 
certainly  distinguisht.     The  basisphenoid  can  be 
traced  forward  about  30  mm.   from  the  condyle. 
It  is  7  mm.  wide  posteriorly  and  narrows  ante- 
riorly.   It  is  doubtful  if  the  pterygoids  came  in 
contact  at  any  point.    The  pterygoid  region,  where 
narrowest,  is  14  mm.  wide.    Toward  the  anterior 
end  of  the  basisphenoid  there  is  on   each  side, 
Fig.  17. — Glyptops  pUcatulus.    Carapace,    xj.   between  this  bone  and  the  pterygoid,  a  foramen. 
No.   336  A.  M.  N.  H.     Shows  the  various    such  as  is  seen  in  Bn'ena,  probably  for  the  passage 
bones  and  many  of  the  scutes.  of  a  vein.     In  the  skull   here  described  a  groove 

Fig.  18. — Glyptops  pUcatulus.  Carapace,  xj.  proceeds  backward  for  some  distance,  and  the 
No.  1357  Yale  University.  Shows  onlv  the  appearance  is  such  that  the  presence  of  a  slit 
bones.     Figure  from  U.  S.  G.  S.  between  the  bones  is  suspected.     The  ectoptery- 


PLEUROSTERNID^. 


49 


goid  processes  are  very  large.    The  anterior  region  of  the  roof  of  the  mouth  is  damaged, 
so  that  httle  is  to  be  learned  from  it. 

The  lower  jaw  is  closely  prest  against  the  remainder  of  the  skull.  From  its  tip  to  the 
hinder  end  is  54  mm.  The  two  rami  are  co-ossified.  The  symphysis  is  10  mm.  long.  All  the 
bones  are  smooth. 

Here  it  may  be  permitted  to  make  some  remarks  on  Baur's  description  of  the 
skull  of  this  species.  The  sculpture  of  the  bones  is  not  exactly  like  that  of  the  shell, 
it  being  finer  and  more  pustular.  Baur,  in  opposition  to  Marsh,  states  that  the 
exoccipitals  take  part  in  the  formation  of  the  condyles.  It  seems  probable  that 
Baur  came  to  this  conclusion  from  the  presence  of  the  pit,  making  the  assumption 
that  this  is  found  only  where  the  basioccipital  meets  the  exoccipital.  In  the  skull 
of  a  Bridger  Baena  the  basioccipital  takes  no  part  in  the  condyle,  and  yet  there  is  a 
very  distinct  pit.  The  skull  of  Glyptops  in  the  American  Museum  does  not  enable 
us  to  decide  the  question. 

Portions  of  7  of  the  cervicals  are  preserved  in  the  American  Museum  specimen,  the  first 
not  being  present.  As  a  whole,  the  neck  seems  to  have  been  short  and  slender.  Its  total 
length  did  not  exceed  120  mm.,  the  carapace  being  300  mm.  The  articular  end  of  the  second 
cervical  has  a  diameter  of  only  4  mm.,  while  that  of  Trachemys  elegans,  with  a  carapace  230  mm. 
long,  has  a  diameter  of  5  mm.  All  the  cervicals  present  a  deep,  comprest,  and  sharp  keel  along 
the  lower  side,  thickening  behind.  All,  excepting  probably  the  first,  possest  transverse  pro- 
cesses, each  about  4  mm.  long.  All  have  the  anterior  and  posterior  articular  surfaces  more  or 
less  concave.  The  hinder  end  of  the  eighth  is  concave,  without  the  convex  portion  men- 
tioned by  Dr.  Baur.  The  anterior  end  also  is  concave.  The  postzygapophyses  are  close 
together,  but  have  not  coalesct.  The  hinder  end  of  the  seventh  is  nearly  flat,  and  we  may 
suppose  that  it  has  entered  on  the  first  stages  in  forming  a  convex  articulation.  Barring  the 
articular  surfaces,  these  cervicals  resemble  closely  those  oi  Baena. 

The  first  dorsal  vertebra  has  a  very  distinct  keel  along  its  lower  side  and  the  anterior  end 
of  the  centrum  is  concave.  The  first  rib  is  long,  about  57  mm.,  and  has  apparently  lost  a 
portion  of  its  extremity.  It  has  a  diameter  of  about  5  mm.  and  is  applied  closely  to  the  rib  of 
the  first  costal  plate.  The  rib-heads  are  much  like  those  oi  Baena.  The  one  belonging  to  the 
first  costal  plate  is  the  broadest,  about  12  mm.  in  diameter.  Most  of  the  others  are  smaller, 
about  8  mm.  wide.  The  last  two  are  considerably  smaller.  The  tenth  rib  is  short  and  thick, 
its  length  being  15  mm.,  its  diameter  4  mm.  Its  outer  end  is  somewhat  enlarged,  to  support 
the  ilium,  and  it  is  applied  against  the  lower  surface  of  the  eighth  costal.  The  first  sacral  rib  is 
the  larger,  about  20  mm.  long,  and  expanded  at  its  outer  end  to  a  width  of  10  mm.  The 
second  sacral  rib  is  much  slenderer.  Both  of  them  resemble  corresponding  parts  of  Chelydra 
and  Baena. 

The  carapace  (plate  6;  text-fig.  17)  is  300  mm.  long  in  the  midline,  and  272  mm.  wide.  It 
is  much  deprest,  but  this  is  due  to  some  extent  to  distortion  during  burial,  for  some  of  the 
costals  and  peripherals  are  spread  apart.  Anteriorly  the  border  is  slightly  excavated  in  the 
midline.  Posteriorly  the  carapace  is  truncated  and  broadly  and  shallowly  excavated.  Marsh's 
figure  represents  his  specimen  as  more  rounded  behind.  The  peripherals  extended  outward 
nearly  horizontally.    Their  borders  are  subacute  near  the  midline  in  front  and  behind,  but 

they  thicken  and  become  more  obtuse  toward  and  over  the 
bridges.  The  whole  surface  of  the  carapace  and  of  the  plastron 
is  finely  sculptured  with  tubercles  and  winding  ridges,  there 
being  about  12  ridges  in  a  line  10  mm.  long. 

The  nuchal  bone  is  quadrilateral,  with  the  broadest  side 
joining  the  first  costals  and  the  first  neural.  This  side  is  80 
mm.  long.  The  free  border  is  42  mm.  long.  The  accompanying 
table  presents  the  dimensions  of  the  neurals. 

There  is  in  this  specimen  a  single  suprapygal.  Baur  states 
that  in  the  Yale  specimens  there  are  two  of  these  bones,  but 
Marsh  figures  only  one.    A  sketch  in  the  writer's  possession. 


Neural. 

Length. 

Width. 

, 

38 

^3 

2 

3° 

z6 

3 

3^ 

24 

4 

z6 

^3 

5 

27 

^3 

6 

19 

>9 

7 

18 

20 

8 

ig 

21 

50 


FOSSIL   TURTLES    OF   NORTH    AMERICA. 


made  apparently  for  Dr.  Baur,  and  here  reproduced  (fig.  i8),  represents  the  first  as  small  and 
occupying  the  space  between  the  costals  of  the  eighth  pair.  The  suprapygal  of  No.  336  is 
large.  Its  length  is  36  mm.,  its  width  anteriorly  14  mm.;  the  maximum  64  mm.;  the  posterior 
width  38  mm.    This  bone  somewhat  resembles  in  form  that  of  a  Testudo. 

The  costal  plates  narrow  in  succession  backward.  The  peripherals  are  11  in  number  on 
each  side.  Anteriorly  and  posteriorly  they  are  high;  over  the  bridges  they  are  low.  The 
first  and  second  have  a  height  of  35  mm.;  the  fifth,  18  mm.;  the  ninth,  40  mm. 


Figs.  19-27.     Glyptops  plicatulus.    No.  336  A.  M.  N.  H. 

23.  Felvis   Irom    below.      X^.     Somewhat    crusht 


19.  Plastron.     X  J.    Shows  bones  and  many  of  the 

scute  areas. 

20.  Scapula.      X  if  •     Procoracoid    process,  on    the 

right,  shortened  by  crushing. 

21.  Coracoid    and     procoracoid    process    of    scap- 

ula.    XJ. 

22.  Right  humerus.     X?-     Dorsal  surface. 


Pelvis   from    below, 
fore  and  aft. 

24.  Pelvis  from  left  side.     X§. 

25.  Right  femur.     X§.    From  tibial  border. 

26.  Right  femur.     X§.    From  dorsal  surface;  some- 

what crusht. 

27.  Digital  bones.     Xi- 


The  plastron  is  flat  (fig.  19).  Its  length  is  260  mm.  The  anterior  lobe  is  80  mm.  long; 
its  width  at  the  base,  122  mm.  The  edges  are  thick  and  rounded.  The  bones  at  the  epihyo- 
plastral  suture  are  8  mm.  thick.  The  entoplastron  is  43  mm.  long  and  47  mm.  wide  and 
broadly  rounded  behind.  The  hyoplastrals  meet  at  the  midline  about  50  mm.  The  meso- 
plastra  differ  in  width  at  the  midline,  the  left  being  30  mm.  wide,  the  right  22  mm.  The 
hinder  lobe  is  78  mm.  long  and  106  mm.  wide  at  the  base.  The  hinder  border  is  truncated. 
The  free  borders  are  acute-edged.    The  bone  thickens  rapidly  from  the  borders  to  about  10  mm. 

The  plastral  bones  are  joined  to  the  bridge  peripherals  by  the  usual  rough  sutures.  Strong 
buttresses  rise  to  the  costals. 

The  sulci  bounding  the  epidermal  scutes  are  extremely  obscure  and  in  many  places  can 
not  be  determined.  Where  they  can  be  observed  they  have  been  represented  in  the  diagram- 
matic figures.  Those  of  the  plastron  are  less  difficult  of  observation.  The  gular  scutes  are 
very  broad,  the  sulci  bounding  them  posteriorly  curving  outward  and  backward  to  near  the 
epihyoplastral  suture.  The  intergulars  can  not  be  made  out  on  No.  336,  but  they  are  shown 
by  Baur  in  a  figure  furnisht  for  him  by  the  United  States  Geological  Survey  (plate  5,  fig.  5). 


PLEUROSTERNID^.  5I 

These  intergulars  slightly  overlap  the  entoplastron.  The  humero-pectoral  sulcus  passes 
behind  the  entoplastron.  Dr.  Baur's  figure  of  the  median  sulcus  represents  it  as  running  an 
exceedingly  irregular  course.  In  fig.  19  this  sulcus  is  probably  represented  much  too  straight. 
On  the  bridges  are  very  distinct  inframarginals,  as  represented  in  fig.  19.  Only  the  angles 
of  these  extend  over  on  the  peripheral  bones. 

Dr.  Baur  states  that  a  nuchal  scute  is  present  in  this  species,  but  in  No.  336  it  can  not 
be  distinguisht  with  certainty.  On  most  of  the  peripherals  the  sulci  may  be  seen,  both  on 
the  upper  and  the  lower  sides.  The  boundaries  of  the  three  anterior  vertebrals  have  been 
determined  quite  satisfactorily.    The  width  of  these  scutes  is  about  90  mm. 

Dr.  Baur  has  briefly  described  the  shoulder-girdle.  This  is  present  in  specimen  No.  336 
(figs.  20,  21)  altho  the  distal  portions  of  the  coracoids  are  damaged  so  that  their  exact  form 
can  not  be  determined.  The  left  half  of  the  girdle  is  least  injured  and  distorted.  Here  we 
find  the  scapula,  the  procoracoid  process,  and  the  coracoid  standing  at  nearly  right  angles  with 
one  another.  In  this  respect  they  are  much  as  in  Chelydra.  The  scapula  is  relatively  shorter 
than  in  Chelydra,  and  the  procoracoid  is  shorter  still.  The  lower  end  of  the  scapula  is  strongly 
comprest.  The  glenoid  fossa  is  removed  outward  some  distance  from  the  perpendicular 
portion  of  the  scapula.  This  fossa  presents  some  interesting  peculiarities.  It  measures  7  mm. 
by  9  mm.  and  it  has  the  long  axis  directed  nearly  horizontally.  The  fossa  of  Chelydra,  nearly 
of  the  same  shape,  is  directed  nearly  perpendicularly.  Furthermore,  there  is,  running  along 
near  the  lower  border  of  the  fossa,  a  prominent  ridge,  which  is  found  to  correspond  to  a  groove 
on  the  head  of  the  humerus.  Nothing  of  the  kind  is  found  in  either  Chelydra  or  Testudo, 
except  in  the  most  rudimentary  form.  However,  in  a  specimen  of  Trachemys  rugosa  there  are 
found  similar  structures;  but  here  too,  the  long  axis  of  the  fossa  is  directed  strongly  upward. 
Examination  of  the  naturally  articulated  parts  of  Trachemys  shows  that  the  motion  of  the 
humerus  is  nearly  confined  to  a  plane  which  is  directed  backward  and  downward.  The 
motion  of  the  humerus  of  a  Testudo,  with  its  round  head,  is  much  more  free  and  varied.  The 
Testudo  is  a  tortoise  adapted  solely  for  walking;  the  Trachemys  is  to  a  great  extent  a  swimmer. 

Dr.  Baur  states  that  the  fore  limb  of  Compsemys  {Glyptops)  is  long  and  resembles  the 
elements  of  the  Emydidae.  However,  the  humerus  (fig.  22)  is  a  little  shorter  proportionally 
than  in  Trachemys  rugosa  and  the  limb  is  rather  feeble.  The  humerus  is  but  little  more  than 
one-half  as  long  proportionally  as  that  of  Chelydra.  The  bone  is,  however,  not  so  slender 
as  that  of  Trachemys,  but  has  more  of  the  form  and  proportions  of  Chelydra.  This  applies 
also  to  the  size  of  the  radial  and  ulnar  tuberosities.  The  distal  end  of  the  humerus  has  points 
of  interest.  Its  breadth  is  like  that  of  Chelydra.  There  is  distinct  evidence  of  the  presence 
of  a  deep  coronoid  depression.  The  ectepicondylar  foramen  pierces  the  bone  at  a  distance 
of  1 1  mm.  above  the  condyle.  The  trochlear  surface  reminds  one  of  that  of  some  mammal. 
Instead  of  forming  an  elongated  smooth  surface,  convex  in  both  directions,  it  presents  two 
prominent  ridges  separated  by  a  groove.  The  distal  end  of  the  humerus  of  Trachemys  rugosa 
presents  a  somewhat  similar  structure,  but  the  guiding  ridges  are  far  less  prominent.  As  in 
Glyptops,  the  most  prominent  one  is  that  for  the  head  of  the  radius.  The  result  of  these 
arrangements  must  be  that  the  motion  of  the  forearm  of  both  genera  is  confined  to  one  plane, 
like  that  of  the  forearm  of  a  man. 

There  is  this  difference,  however,  between  the  humeri  of  Trachemys  and  Glyptops.  In 
the  former  these  ridges  run  nearly  parallel  with  a  plane  passing  through  the  long  axis  of  the 
head  of  the  humerus.  The  effect  of  this  is  to  make  the  forearm  move  in  the  same  plane  as 
the  upper  arm;  that  is,  downward  and  backward.  In  Glyptops,  on  the  other  hand,  ths  ridges 
of  the  trochlear  surface  are  directed  at  an  angle  of  about  45°  with  the  plane  of  the  head  of  the 
humerus.  Hence,  when  the  limb  is  drawn  backward,  the  humerus  moves  in  a  horizontal 
plane,  while  the  forearm,  if  flext,  would  move  downward  and  backward. 

One  ulna  is  present.  It  is  slightly  longer  proportionally  to  the  humerus  than  it  is  in 
Trachemys,  and  its  distal  end  is  broader.    Of  the  hand  the  writer  can  say  nothing. 

Baur  has  dealt  with  the  pelvis  without  figuring  it.  He  errs  with  regard  to  the  inner  ramus 
of  the  pubis,  when  he  says  it  is  a  slender  element  and  that  the  ischium  is  larger  than  the  pubis. 
The  contrary  is  true  (figs.  23,  24).  The  pubis,  aside  from  the  lateral  processes,  does  not  differ 
greatly  from  that  of  Chelydra  or  Testudo.  In  the  specimen  before  me  it  has  an  antero-posterior 
extent  of  at  least  25  mm.    It  is  quite  deeply  notcht  in  front.    Baur  is  possibly,  but  not  certainly 


y 


52 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


correct  when  he  states  that  it  did  not  come  in  contact  in  the  midline  with  the  ischium.  The 
pelvis  in  the  specimen  here  described  has  probably  suffered  some  antero-posterior  crushing, 
but  the  pubes  and  ilia  do  join.  In  Baena,  whose  pelvis  is  identical  with  that  of  Glyptops, 
there  is,  at  least  in  aged  individuals,  a  union  of  these  elements  in  the  midline. 

The  lateral  pubic  processes  are  quite  different  from  those  o{  Chelydra,  being  more  massive. 
At  their  extremities,  where  they  come  into  contact  with  the  xiphiplastra,  they  are  enlarged  and 
rough.  Above  this  they  are  constricted  into  a  sort  of  neck.  The  ischium  is  narrow  from  front 
to  back,  about  12  mm.,  and  thin,  as  in  Baena.  Its  hinder  lower  border  is  nearly  straight  until 
the  processes  are  reacht  on  which  thg  ischium  rests  on  the  plastron.  These  processes  stand 
at  a  distance  of  30  mm.  apart.  Each  is  terete,  pointed  at  its  free  end,  and  about  15  mm.  long. 
They  are  directed  backward. 

The  ilium  is  not  greatly  different  from  that  of  Chelydra,  except  that  it  is  shorter  and 
proportionately  stouter.  The  sacrum  is  in  general  smaller  and  weaker  than  that  of  Chelydra, 
except  that  the  distance  of  the  acetabula  apart  is  the  same.  The  pelvis  is  essentially  like  that 
of  Baena  and  all  parts  should  be  compared  with  those  of  the  latter  genus. 

The  only  portion  of  the  hind  limb  present  is  the  right  femur  and  probably  some  foot  bones. 
Dr.  Baur  states  that  the  femur  agrees  with  that  of  the  Emydidae.  In  length,  it  is  exactly  that 
of  the  Trachemys  mentioned  and  relatively  much  shorter  than  that  of  Chelydra.  It  is  much 
curved,  especially  toward  the  distal  end  (figs.  25,  26).  The  greater  trochanter  is  separated 
from  the  lesser  by  a  deep  fossa.  From  the  greater  trochanter  a  prominent  crest  runs  down 
on  the  hinder  side  of  the  femur  one-third  or  more  of  its  length.  The  distal  end  of  the  femur  is 
damaged,  but  it  presents  indications  of  having  had  the  condyles  more  prominently  developt 
than  in  turtles  in  general.    The  total  length  of  the  femur  in  a  straight  line  is  61  mm. 

One  complete  toe,  which  probably  belonged  to  a  hind  foot,  is  preserved  with  the  parts  in 
place  (fig.  27).  It  shows  a  metatarsal  and  three  phalanges,  and  these  have  a  total  length  of  42 
mm.    The  metatarsal  is  slender  and  has  a  length  of  22  mm. 


31- 


Figs.  28-31.     Glyptops  ccclatus.    Type  specimen  in  U.  S.  N.  M. 


28.  Portions  of  first  and   second    peripherals  and 

first  costaL     Xi- 

29.  Section  across  second  peripheral.     Xf. 


30.  Section  across  hinder  peripheraL 

31.  Proximal  end  of    costal  bone,  showing  scute 

areas  and  sculpture.     X  J. 


Glyptops  caelatus  sp.  nov. 
Plate  7,  figs.  I,  2;  text-figs.  28-31. 

The  fragments  of  tortoise  to  which  this  name  is  given  were  collected  by  Mr.  J.  B.  Hatcher, 
in  1887,  at  Muirkirk,  Maryland,  in  deposits  belonging  to  the  Potomac  formation  of  the  Lower 
Cretaceous.  The  fragments  consist  of  portions  of  costals  and  of  peripherals.  The  most 
important  fragment  consists  of  the  right  first  costal,  a  part  of  the  first  and  most  of  the  second 
peripherals.  There  is  also  a  part  of  a  costal  situated  further  back  in  the  carapace.  These 
bear  the  number  1930,  and  belonged  doubtless  to  one  individual.  There  is  present  also  a 
hinder  peripheral  and  a  first  right  peripheral  which  have  the  number  1939.  There  are  also 
two  fragments  of  costals  of  a  young  individual,  one  of  which  shows  the  rib-head.  The  bones 
beanng  the  number  1930  are  regarded  as  being  the  type  of  this  species.  All  the  specimens 
are  in  the  United  States  National  Museum. 


PLEUROSTERNID^.  53 

The  first  costal  (plate  7,  fig.  i;  text-fig.  28)  has  a  length,  from  its  union  with  the  neural 
to  the  pointed  distal  end,  of  103  mm.  and  a  width,  fore  and  aft,  of  50  mm.  The  thickness  of 
the  costal  at  the  posterior  border  is  about  5  mm.  The  anterior  half  of  the  bone  is  thickened 
to  as  much  as  18  mm.  to  form  a  shoulder  for  the  reception  of  the  axillary  buttress  of  the  plastron. 
The  latter  must  have  been  considerably  more  strongly  developt  than  in  Glyptops  plicatulus. 
The  head  of  the  rib  is  stout.  The  first  rib  lies  in  front  of  and  against  the  rib  of  the  first  costal 
plate.  The  first  peripheral  lacks  its  anterior  half  so  that  its  antero-posterior  extent  can  not  be 
accurately  determined.  However,  the  missing  portion  is  partly  supplied  by  No.  1939.  The 
anterior,  or  free,  border  is  obtuse.  At  one  end  is  the  sutural  surface  for  union  with  the  nuchal 
bone.  It  appears  quite  unlikely  that  there  was  any  considerable  excavation  in  the  front  of  the 
carapace  for  the  neck  of  the  animal.  The  first  peripheral  of  No.  1930  was  30  mm.  wide, 
parallel  with  the  edge  of  the  shell.  The  second  peripheral  has  a  fore-and-aft  extent  of  40  mm. 
and  the  width  along  the  free  border  is  the  same.  This  border  also  is  obtuse  (fig.  29)  and  at  a 
short  distance  from  the  edge  the  thickness  is  about  8  mm.  It  resembles  very  closely  the 
corresponding  one  in  G.  plicatulus. 

The  posterior  peripheral,  probably  the  tenth  of  the  right  side,  numbered  1939,  is  39  mm. 
wide  from  the  free  border  to  the  union  with  the  costal,  and  35  mm.  along  the  free  border. 
Its  thickness,  where  it  joined  the  costal,  is  10  mm.,  and  it  has  come  down  to  an  acute  free 
edge  (fig.  30).     Its  form  is  therefore  that  of  a  thin  wedge. 

The  fragment  of  costal  numbered  1930  (plate  7,  fig.  2;  text-fig.  31)  shows  neither  the 
length  nor  the  breadth.  The  piece  is  35  mm.  wide  and  has  an  epidermal  sulcus  running 
parallel  with  the  sutural  border  and  27  mm.  distant  from  it.  The  costal  was  therefore  of 
considerable  total  width.  Its  thickness  is  only  5  mm.  The  true  rib  does  not  appear  on  the 
lower  surface,  as  it  does  in  G.  plicatulus. 

The  sulci  of  this  species  are  narrow  and  shallow,  but  quite  distinct.  Apparently  the 
epidermal  scutes  resembled  those  of  G.  pi icatulus,  nhho  neither  the  vertebrals  nor  the  marginals 
were  so  broad  as  in  the  latter  species. 

The  sculpture  of  the  surface  is  quite  different  from  that  of  G.  plicatulus.  In  the  latter  it 
has  a  more  granular  appearance  and  is  produced  by  distinct  raised  dots  and  by  short  ridges 
formed  of  coalesct  dots.  In  G.  aelatus  the  dots  are  larger,  the  ridges  also  broader,  longer,  and 
smoother.  The  spaces  between  the  elevations  are  as  wide  as  the  latter.  In  the  centers  of  the 
bony  surfaces  the  ridges  are  irregular  in  length  and  direction,  and  often  vermiculate.  Border- 
ing the  sutural  edge  is  a  broad  band  in  which  the  ridges  and  grooves  run  at  right  angles  with 
the  suture.    On  the  costals  this  band  may  be  as  much  as  13  mm.  wide. 

Glyptops?  belviderensis  (Cragin). 
Plate  7,  figs.  4,  5. 

Plesiochelys    belviderensis,    Cragin,    Colorado    Coll.    Studies,  v,  1894,  p.  71,   pi.  ii,  figs.   1-8. — Hay, 
Bibliog.  and  Cat.  P'oss.  Vert.  N.  A.,  1902,  p.  439. 

The  present  writer  has  not  seen  the  type  specimens  of  this  species.  They  belong  to  Colo- 
rado College,  Colorado  Springs,  Colorado.  They  consist  of  two  first  costals,  fragments  of  other 
costals,  a  neural  bone  and  a  dorsal  vertebral  centrum.  These  bones  were  found  in  the  Kiowa 
shales,  a  portion  of  the  Comanche  series  and  near  the  top  of  the  Lower  Cretaceous.  The 
locality  is  near  Belvidere,  Kiowa  County,  Kansas. 

Dr.  Cragin  referred  these  bones  to  the  genus  Plesiochelys,  but  there  appears  to  be  no  special 
reason  for  this  assignment.  The  species  of  this  genus,  so  far  as  certainly  known,  belong  to  the 
Jurassic,  Kimeridge,  and  Wealden  of  Europe.  The  sculpture  of  the  costals  of  Cragin's  species 
suggests  Glyptops  calatus  and  accordingly  the  species  is  referred  with  doubt  to  Glyptops.  Two 
of  Cragin's  figures  are  here  reproduced.  Fig.  5,  plate  7,  represents  a  neural  seen  from  the 
under  side.  It  is  relativelyconsiderably  broader  than  theneuralsof  P/^j/oc A^/jyj  (Zittel  's  Hand- 
buch  Palaeontologie,  p.  545,  fig.  502;  Lydekker's  Cat.  Foss.  Rept.,  pt.  in,  fig.  44).  The  front 
costals  figured  by  Cragin  are  narrow,  the  width  being  38  mm.,  the  length  82  mm.  The  longest 
costal  was  1 1 1  mm.  long.  The  upper  surface  of  the  shell  is  said  to  be  ornamented  with  deli- 
cate vermicular  grooving  and  pitting.  Fig.  4,  plate  7,  is  intended  to  represent  this  sculpture 
of  the  costals. 


54 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


Glyptops  pervicax  sp.  nov. 

Text-fig.  31. 

The  type  of  the  present  species  is  No.  1018  of  the  American  Museum  of  Natural  History. 
It  was  collected  by  Mr.  Barnum  Brown,  in  1902,  from  near  the  base  of  the  Graneros  shales  of 
the  Benton  deposits,  in  Yellowstone  County,  Montana.  These  shales  are  of  marine  origin. 
The  locality  more  exactly  described  is  on  Brush  Creek,  10  miles  east  of  Pryor,  in  the  county 
named.  The  remains  consist  of  the  front  and  the  dorsal  region  of  the  carapace  and  the  greater 
part  of  the  plastron.  The  shell  is  that  of  an  aged  individual.  Not  a  trace  appears  of  the  sutures, 
so  that  the  structures  can  not  be  in  all  respects  accurately  determined. 

The  carapace  had  a  length  of  about  375  mm.  There  was  apparently  a  broad,  low,  rounded 
ridge  running  along  the  back  in  the  areas  of  the  second,  third  and  fourth  vertebral  scutes. 
At  the  midline  of  the  front,  over  the  neck,  there  was  a  rounded  excavation.  The  anterior  free 
border  was  obtuse  and  about  10  mm.  thick.    The  sulci  are  obscure,  due  mostly  to  an  adhering 

incrustation  of  clay,  but  some  of  them  can  be  traced.  Portions  of 
the  second,  third  and  fourth  vertebral  scutes  may  be  mapt  out. 
They  were  considerably  broader  than  long.  The  third  was  83  mm. 
long  and  had  a  maximum  width  of  130  mm. 

On  the  visceral  surface  of  the  carapace  may  be  seen  the  bases 
of  the  rib-heads.  These  were  not  so  strongly  developt  as  in  G. 
plicatulus.  In  the  latter,  as  shown  in  No.  336,  A.  M.  N.  H.,  the 
rib-heads  have  a  diameter  of  10  mm.,  while  in  G.  pervtcax  the 
diameter  is  about  7  mm.  in  a  larger  individual.  The  whole  series 
is  shown,  on  one  side  at  least.  The  extremity  of  the  tenth  rib 
was  co-ossified  with  the  eighth  costal  about  10  mm.  behind  the 
rib-head  of  the  costal  named.  On  the  first  costal  plate  there  is  a 
prominent  ridge  which  ran  from  the  first  and  second  vertebral 
centra  to  the  border  of  the  third  peripheral  and  met  the  buttress 
of  the  plastron.  At  the  peripheral  this  ridge  has  a  width  of  about 
18  mm.  and  a  thickness  of  11  mm.  How  high  the  buttress 
ascended  can  not  be  determined,  for  the  suture  is  obliterated. 
It  appears  that  the  buttresses  and  the  costal  ridges  meeting  them 
were  more  strongly  developt  in  this  species  than  in  G.  plicatulus. 
The  total  length  of  the  plastron  (fig.  32)  was  very  close  to 
335  mm.  The  anterior  lobe  is  broadly  rounded  in  front,  as  it  is  in  G.  plicatulus.  Its  length 
is  85  mm.,  its  width  about  150  mm.  The  free  border  is  obtuse.  The  bone  is  about  10  mm. 
thick.  The  limits  of  the  entoplastron  can  not  be  determined.  On  the  upper  surface  of  this 
lobe,  about  18  mm.  behind  the  anterior  border,  there  are  two  low  processes,  one  on  each  side 
of  the  midline,  which  were  probably  for  ligamentous  attachment  of  the  procoracoid  pro- 
cesses of  the  scapula.  In  G.  plicatulus  the  corresponding  processes  are  about  34  mm.  from 
the  border. 

The  bridge  has  a  width  of  140  mm.  Its  inner  end  starts  from  a  low  ridge  which  runs  from 
the  free  border  of  the  anterior  lobe  to  that  of  the  posterior.  The  outer  ends  of  the  bridges  are 
mostly  missing. 

The  length  of  the  posterior  lobe  was  approximately  1 10  mm.;  the  width  at  the  base,  142  mm. 
The  free  borders  are  acute  on  a  level  with  the  lower  surface.  From  this  edge  the  bone  is  beveled 
and  rises  to  a  thickness  of  12  mm.  Beyond  this,  toward  the  midline,  the  thickness  diminishes 
again.  At  the  hinder  end  of  the  lobe  the  thickness  is  only  5  mm.  Most  of  the  hinder 
extremity  of  the  lobe  is  missing.  A  small  fragment  is  present,  but  on  account  of  some  doubts 
it  has  not  been  used  in  the  figure.  On  the  upper  surface  of  the  lobe,  very  close  to  its  border, 
there  is  a  circular  depression  about  7  mm.  in  diameter,  which  received  a  process  of  the  ischium. 
On  the  same  surface  about  60  mm.  behind  the  inguinal  notch,  begins  another  depression,  con- 
siderably larger,  for  the  reception  of  the  pubis. 

Most  of  the  plastral  scutal  areas  can  be  mapt  out.  The  intergulars  measured  32  mm. 
along  the  midline.  Taken  together,  they  had  a  width  of  about  28  mm.  It  can  not  be  determined 
certainly  whether  or  not  they  were  divided  at  the  midline.    The  gulars,  as  in  G.  plicatulus.  had 


Fig.  32. — Glyptops  pervicax. 
Plastron  of  type.  X  J. 
Shows  scute  areas.  No. 
1018  A.  M.  N.  H. 


PLEUROSTERNID^. 


55 


been  crowded  out  of  contact  with  each  other.  The  humerals  measured  47  mm.  at  the  midline; 
the  pectorals,  63  mm.;  the  abdominals,  54  mm.;  the  femorals,  about  78  mm.  There  were 
doubtless  inframarginals  on  the  bridges,  but  the  sulci  are  obscure. 

Since  the  preceding  description  was  written  a  second  specimen  has  been  made  available 
for  study.  This  was  collected  by  Mr.  Barnum  Brown,  in  1904,  in  the  Crow  Reservation, 
Montana,  at  a  point  about  50  miles  southeast  from  Billings  and  about  25  miles  east  of  Pryor. 
The  catalog  number  of  the  specimen  in  the  American  Museum  is  6071.  It  furnishes  more  of 
the  shell  than  does  the  type,  but  unfortunately  the  plastron  is  fractured  and  faulted  obliquely 
to  its  length  and  the  carapace  is  fractured  and  faulted  in  several  directions. 

The  carapace  was  about  325  mm.  long  and  the  width  is  close  to  the  same.  The  anterior 
border  is  preserved  on  each  side  to  behind  the  axillary  notches;  it  is  obtuse  and  about  10  mm., 
thick.  The  surface  presents  the  same  kind  of  sculpture  as  the  plastron,  consisting  of  low  wind- 
ing ridges.  The  sulci  are  rather  obscure,  but  the  vertebral  scutes  were  broad,  as  in  the  type, 
while  the  right  third  costal  is  seen  to  have  been  only  70  mm.  high. 

The  length  of  the  plastron  appears  to  have  been  close  to  295  mm.  The  bridge  is  125  mm. 
wide.  From  the  line  joining  the  free  borders  of  the  anterior  and  posterior  lobes  of  the  plastron 
the  bridge  rose  to  the  free  border  of  the  carapace,  a  distance  of  about  1 10  mm.  The  hinder 
lobe  has  a  width  of  125  mm.  and  a  width  of  1 10  mm.  at  its  base.  At  theendsof  thefemoro-anal 
sulci  the  width  is  83  mm.  The  hinder  border  confirms  the  accuracy  of  fig.  32.  On  the  bridges 
are  some  indications  of  inframarginal  scutes,  too  obscure  to  be  traced. 


ing.h 


Figs.  33  and  34.     Glyptops  depressus.     Specimen  in  U.  S.  N.  M. 

33.  Carapace  of  type.      Xi- 

34.  Portion  of  plastron  of  type.      Xi*     ax-b^  axillary  buttress;    ent,  entroplastron;    epi,   epiplastron;    /ryo, 

hyoplastron;   Ay^o,  hypoplastron;    m^.  fc,  inguinal  buttress;   m«j,  mesoplastron, 

Glyptops  depressus  sp.  nov. 

Text-figs.  33,  34. 

The  type  of  this  species  belongs  to  the  United  States  National  Museum.  It  appears  to 
have  been  secured  by  one  of  Professor  O.  C.  Marsh 's  collectors  in  1889,  inasmuch  as  it  bears 
his  packing  number  "1998.  Box  3."  With  the  specimen  comes  a  statement  by  Mr.  Whitman 
Cross,  of  the  United  States  Geological  Survey  as  follows: 

"'No.  2  Box  B.  '89,'  (Cannon's  designation).  An  isolated  fragment.  (I  think  this  fossil  is 
from  the  Denver  beds,  from  the  nature  of  the  sandstones  between  the  shells  and  the  apparently 
zeolitic  material  in  cells  of  the  bone.)" 

Professor  Marsh  has  recorded  Compsemys  plicatida  from  the  Denver  beds,  but  whether  on 
the  evidence  of  this  specimen  can  not  be  determined.    The  probabilities  that  the  same  species 
is  found  from  the  top  of  the  Jurassic  to  the  top  of  the  Cretaceous  are  remote. 
•  •  The  specimen  presents  considerable  portions  of  the  carapace  and  of  the  plastron.     The 


Neural. 

Length. 

Width. 

I 

12 

9 

2 

•3 

>3 

3 

12 

M 

4 

II 

H 

5 

lO 

I2.S 

6 

'5 

14 

7 

I4± 

>5± 

r6  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

hinder  end  of  the  carapace  has,  at  the  time  of  burial,  been  crusht  down  to  the  plastron.  After 
having  been  weathered  out  of  the  matrix  the  specimen  suffered  further  damage,  all  that  part 
behind  the  seventh  neural  having  been  destroyed.  All  the  peripherals  are  likewise  missing. 
The  length  of  the  carapace  (fig.  33)  was  originally  about  120  mm.;  the  width  was  about 
I  ID  mm.  The  shell  is  deprest  and  was  so  probably  during  life.  The  surface  of  the  carapace 
presents  indistinct  evidences  of  having  been  sculptured  finely  as  in  G.  plicatulus,  or  possibly 
more  like  Compsemys  victa.  The  anterior  border  of  the  nuchal  bone  is  eroded  away.  The 
width  of  the  bone  was  close  to  38  mm.  Its  form  is  quite  different  from  that  of  G.  plicatulus. 
In  the  latter  the  postero-lateral  borders  are  nearly  parallel  with  each  other,  while  in  the  present 
species  they  make  nearly  a  right  angle.  The  accompanying  table  presents  the  dimensions 
of  the  neurals  present. 

The  great  relative  width  of  these  neurals  as  compared  with  those  of  G.  plicatulus  is  striking. 

The  proximal  end  of  the  first  costal  is  14  mm.  wide,  while 
the  width  at  the  middle  of  the  length  is  26  mm.  In  G.  plicatulus 
the  median  width  is  little  more  than  the  proximal.  The  succeed- 
ing costals,  at  the  middle  of  the  length,  measure  as  follows: 
The  second,  14  mm.,  the  third,  14  mm.,  the  fourth,  12  mm., 
the  fifth,  1 1.5  mm.,  the  sixth,  19  mm.  The  third  expands 
distally  to  nearly  20  mm.  The  width  of  the  sixth  is  relatively 
much  greater  than  that  of  G.  plicatulus,  but  it  corresponds  to 
the  increased  length  of  the  sixth  neural. 

The  anterior  lobe  of  the  plastron  appears  to  have  been 
rounded  like  that  of  G.  plicatulus.  The  epiplastra  are  badly 
eroded,  but  the  width  of  each  is  13  mm.  The  entoplastron  is  22  mm.  long  and  26  mm.  wide. 
The  antero-lateral  borders  come  together  to  form  an  obtuse  angle;  the  hinder  end  of  the 
bone  is  more  pointed.  The  mesoplastra  are  relatively  broader  fore  and  aft  than  those  of  G. 
plicatulus.  That  of  the  right  side  is  about  15  mm.  wide  at  the  midline;  but  it  expands  later- 
ally, so  that  at  the  middle  of  its  length  the  width  is  24  mm.  That  of  the  left  side  is  23  mm. 
wide  at  the  midline,  but  narrows  laterally  for  a  short  distance.  The  remainder  is  missing.  It  is 
remarkable  how  close  the  hinder  border  of  the  mesoplastron  comes  to  the  inguinal  buttress, 
differing  in  this  respect  much  from  G.  plicatulus. 

There  are  evidences  of  rather  strong  axillary  and  inguinal  buttresses.  They  appear  to 
have  articulated  with  the  distal  ends  of  the  fifth  and  sixth  costals,  at  their  junctions. 

On  account  of  the  weathering  to  which  this  shell  has  been  exposed,  the  boundaries  of  the 
scutes  can  not  be  determined. 

Family  BAENID.*  Cope. 

Amphichelydia  having  the  plastron  firmly  joined  to  the  carapace  by  sutural  union  with  the 
lateral  peripherals  and  with  the  costals  by  strongly  developt  axillary  and  inguinal  buttresses. 
Mesoplastra  usually  meeting  at  the  midline  and  expanding  toward  the  outer  ends.  Skulls,  so 
far  as  known,  broad  and  short.  Temporal  roof  extensive.  Neck  short,  most  of  the  vertebral 
centra  with  only  one  end  concave. 

To  this  family  are  assigned  provisionally  the  genera  Polythorax  Cope  and  Archteochelys 
Lydekker.  The  former  possest  intergular  and  interhumeral  scutes;  the  latter  genus  appears  to 
have  had  a  complete  series  of  median  plastral  scutes. 

The  Ba'enida;  are  closely  related  to  the  Pleurosternidee,  but  the  great  advances  made  in  the 
structure  of  the  cervical  vertebrae  and  the  extension  of  the  plastral  buttresses  seem  to  set  the 
species  off  as  a  distinct  family. 

According  to  our  present  knowledge  this  family  had  an  existence  extending  from  the 
Upper  Jurassic  to  the  Upper  Eocene.  Proba'ena,  a  close  relative  of  Platychelys,  of  the  Upper 
Jurassic  of  Europe,  has  been  described  from  the  Como,  or  Morrison  beds,  occurring  there  with 
Glyptops.  Species  belonging  to  Ba'ena  are  now  known  from  the  Judith  River  beds,  the  Lara- 
mie, and  from  all  the  divisions  of  the  Eocene  to  the  Uinta.  Boremys  Lambe  comes  from  the 
Judith  River  deposits,  Euba'ena  from  the  Laramie,  and  Chisternon  from  the  Bridger. 

Baena  appears  to  be  the  genus  most  prolific  of  species  and  in  most  respects  the  one  most 
advanct.     The  carapace  possesses  a  series  of  8  neurals  and  a  corresponding  number  of  costals. 


BAENID^.  57 

a  nuchal,  I2  pairs  of  peripherals,  and  what  must  be  regarded  as  a  suprapygal,  but  no  true 
pygal.  The  plastron  has,  besides  the  bones  found  in  the  Emydidae,  a  pair  of  mesoplastrals, 
which  usually  reacht  the  midline  and  expanded  greatly  outward  to  join  the  fifth  and  sixth 
peripherals.  The  axillary  and  inguinal  buttresses  are  high  and  wide.  Between  the  axillary  and 
the  inguinal  of  each  side  there  is  a  large  sternal  chamber.  The  axillary  buttress  ascended  to 
a  point  a  little  above  the  lower  border  of  the  first  costal,  meeting  there  the  comprest  rib  of 
the  first  dorsal  vertebra.  The  inguinal  buttress  rose  above  the  lower  border  of  the  fifth  and 
sixth  costals  and  was  articulated  in  a  ridge  rising  from  the  adjacent  borders  of  these  costals. 

The  scutes  of  certain  regions  of  the  shell  are  extremely  variable;  in  other  regions  they  vary 
little.  On  the  carapace  it  is  the  area  occupied  in  the  Emydidae  by  the  first  vertebral,  the  nuchal, 
and  the  first  pair  of  costals  that  is  subject  to  variation  in  its  scutes.  There  may  be  on  each  side 
a  supernumerary  first  costal  scute,  or  it  may  occur  on  only  one  side,  or  it  may  be  wholly  absent. 
In  some  specimens  is  a  second  pair  of  supernumerary  costals,  lying  just  behind  the  nuchals. 
There  may  even  be  a  supernumerary  vertebral  cut  off  from  the  front  of  the  normal  first 
vertebral. 

On  the  plastron  the  gulars  and  intergulars  are  variable  in  form  and  size.  The  infra- 
marginals  vary  in  number  and  size  and  form.  There  are  usually  4,  but  often  the  second  from 
the  axillary  notch  is  missing  on  one  or  both  sides.  In  this  case  the  pectoral  scute  may  or  may 
not  reach  the  marginals. 

In  Chisternon  there  Intervenes  between  the  nuchal  bone  and  the  first  neural  a  large  bone 
that  is  not  present  in  Ba'ena  (fig.  76).  This  the  writer  calls  the  preneural.  In  this  genus  too  the 
occasional  variations  in  the  scutes  of  the  front  of  the  carapace  appear  to  be  quite  the  rule.  The 
normal  first  vertebral  scute  is  transversely  divided,  so  that  there  are  6  vertebrals.  There  is 
usually  on  each  side  a  supernumerary  costal  and  sometimes  two  of  them,  making  6  pairs  of 
these.  The  same  variations  occur  in  the  scutes  of  the  plastron  of  this  genus  that  we  find  in 
Ba'ena.    In  one  case  there  are  5  inframarginals. 

It  would  be  worth  much  to  know  the  meaning  of  these  variations  in  the  bones  and  scutes. 
Is  the  presence  of  the  preneural  in  Chisternon  a  primitive  or  a  secondary  condition  ?  The  writer 
does  not  regard  it  as  probable  that  a  bone  like  the  nuchal  has  become  secondarily  divided,  or 
that  a  new  bone  has  become  develop!  in  that  region.  It  appears  more  probable  that  both  it  and 
the  nuchal  are  continuations  forward  of  the  row  of  neural  bones,  and  that  in  the  most 
advanct  turtles  the  preneural  has  been  crowded  out  of  existence  by  the  growth  of  the  nuchal. 
It  is  evidence  in  favor  of  this  view  that  in  Boremys  Lambe  there  is  present  a  small  preneural; 
also  that  it  is  present  in  the  trionychoid  genera  Aspideretes  and  Plastomenus.  These  genera 
have  probably  inherited  this  bone  from  their  Amphichelydian  ancestors. 

As  regards  the  supernumerary  scutes,  we  have  the  same  questions  to  answer  as  in  the  case 
of  the  prenuchal.  Do  we  have  here  a  breaking  up  of  the  normal  scutes  into  smaller  areas,  as  has 
been  observed  in  some  modern  genera  by  H.  Gadow,  W.  P.  Hay,and  R.E.  Coker;  ordowe  have 
the  normal  number  of  scutes  that  were  present  in  the  earlier  turtles,  together  with  a  tendency 
to  a  suppression  of  some  of  them  ?  We  must  recognize  the  fact  that  on  most  parts  of  the  shell 
the  scutes  are  as  stable  as  in  ordinary  turtles;  altho,  especially  on  the  plastron,  there  is  a  ten- 
dency for  the  sulci  to  wander  somewhat  wildly.  It  is  to  be  noted  that  the  variations  occur  in 
those  regions  where,  in  modern  turtles,  certain  scutes  have  been  supprest.  There  can  be  no 
doubt  that  intergulars  were  primitively  a  possession  of  all  turtles,  but  in  most  Cryptodira  they 
have  been  supprest.  The  primitive  turtles  likewise  possest  on  each  bridge  a  complete  row  of 
inframarginals;  but  in  most  living  genera  these  have  been  eliminated,  with  usually  the  excep- 
tion of  an  axillary  and  an  inguinal  scute.  There  is  probably  not  so  much  evidence  that  one  or 
more  anterior  costal  scutes  have  been  supprest.  In  H.  von  Meyer's  representation  oiAcichelys 
crassipes  (his  Palceomedusa  testa,  Lithogr.  Schiefer,  pi.  xx,  fig.  i)  there  is  shown  a  pair  of  super- 
numerary costal  scutes.  It  is  also  interesting  to  observe  in  that  specimen  2  neurals  between  the 
first  pair  of  costal  bones.  The  anterior  of  these  is  probably  the  preneural.  In  the  modern 
genus  Caretta  there  are  5  pairs  of  costal  scutes.  It  appears  probable  that  the  preneural  and 
the  supernumerary  anterior  vertebral  scute  tended  to  disappear  together. 

The  skull  of  the  Ba'enidce  presents  various  primitive  features.  The  presence  of  distinct 
nasals,  of  lacrimals,  and  a  wide  temporal  roof  is  to  be  cited.  The  writer  has  not  found 
epipterygoids.    The  short  supraoccipital  is  likewise  primitive.    When  we  leave  aside  these 


^8  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

characters  the  skull  appears  to  be  cryptodiran  in  structure.  The  neck  must  be  regarded  as 
primitive  and  intermediate  between  the  Cryptodira  and  the  Pleurodira.  No  features  strictly 
pleurodiran  appear. 

The  cervical  vertebrae  are  described  under  the  species  Baena  riparia  and  Chisternon 
hebraicum.  Considering  the  shortness  of  the  neck,  the  structure  of  the  vertebrae,  and  the  nar- 
rowness of  the  anterior  border  of  the  carapace,  it  seems  probable  that  these  turtles  were  able  to 
find  in  the  shell  little  protection  for  their  heads. 

The  tail  was  long,  resembling  that  of  Chelydra.  With  two  or  three  of  the  skeletons  there 
have  been  found  some  conical  bones,  the  bases  of  which  were  buried  in  the  skin.  Some  of 
these  are  symmetrical  and  it  appears  probable  that  they  were  placed  in  a  row  on  the  upper 
midline  of  the  tail,  as  in  Chelydra.  Others  of  these  bones  are  unsymmetrical,  and  possibly 
formed  parts  of  lateral  rows  on  the  tail.  If  there  had  been  an  armor  of  dermal  bones  on  the 
legs  it  would  probably  have  been  observed  in  some  of  the  specinjens. 

For  the  shoulder-girdle  and  the  pelvis  the  reader  is  referred  to  succeeding  descriptions  of 
Baena  and  Chisternon.     The  limbs  are  of  the  walking  type. 

The  following  key  may  be  of  some  use  in  determining  the  genera  of  the  family: 

A.  No  interhumeral  scute. 
a.  A  preneural  present. 

b.  No  supramarginal  scutes Chisternon 

bb.  Supramarginals  present Boremys 

aa.  No  preneural  so  far  as  known. 

c.  Plastron  projecting  little,  if  at  all,  beyond  front  of  carapace. 

d.  Skull  with  choanx  well  in  front Baena 

dd.  Skull  with  choanae  between  orbits Euba'ena 

ddd.  Skull  unknown.     Plastron  with  median  fontanel Probaena 

cc.  Front  of  plastron  projecting  in  front  of  the  excavated  carapace. 

e.  The  axillary  and  inguinal  buttresses  not  greatly  developt Thescelus 

ee.  Axillary  buttresses  rising  high  on  first  costals Charitemys 

aaa.  Characters  not  well  known.    A  suprapygal  present;  the  vertebral  scutes  broad;  9  pairs 

of  costals  in  type Neurankylus 

AA.  Plastron  with  an  interhumeral  scute. 

a.  Outer  surface  of  plastron  rugose Polythorax 

aa.  Outer  surface  of  plastron  with  globular  elevations Naomichelys 

Genus  PROBAENA  Hay. 

A  genus  closely  related  to  Baena,  but  with  a  more  deprest  carapace,  the  hinder  border  of 
which  is  little  or  not  at  all  notcht.  Vertebral  scutes  broader  than  the  costal  scutes.  Plastron 
with  its  hinder  lobe  rounded.    A  fontanel  (permanent  ?)  between  inner  ends  of  mesoplastra. 

It  is  not  improbable  that  when  the  skull  and  the  cervical  vertebrae  of  this  genus  shall  be 
discovered,  it  will  prove  that  it  belongs  to  the  Pleurosternidae  and  that  the  Baenidae  had  not  yet 
diverged  from  the  former  family. 

Probaena  sculpta  Hay. 

Plate  7,  fig.  5. 
Probaena  sculpta,  Hay,  Ann.  Carnegie  Museum,  11,  1903,  p.  201,  plate  iii,  figs.  I,  2. 

The  type  is  a  small  and  somewhat  imperfect  turtle,  represented  by  about  three-fourths  of 
the  carapace  and  the  greater  portion  of  the  plastron. 

It  belongs  to  the  Carnegie  Museum,  Pittsburg,  and  was  collected  by  Prof.  J.  B.  Hatcher, 
in  1901,  in  the  "Marsh  quarry"  in  the  lower  portion  of  the  Morrison,  or  Atlantosaurus  beds, 
8  miles  north  of  Canyon  City,  Colorado.    The  catalog  number  is  917. 

The  length  of  the  carapace  is  at  present  105  mm.,  very  near  the  original  length;  the 
width  is  70  mm.  The  shell  has  apparently  been  rather  flat,  but  probably  somewhat  less  so  in 
life  than  at  present.  The  greatest  distance  between  the  upper  and  the  lower  surfaces  is  now  27 
mm.  The  borders  of  the  carapace  behind  the  inguinal  notches  are  considerably  flared  upward, 
but  this  may  be  due  somewhat  to  post-mortem  distortion.    This  border  appears  to  have  been 


BAENID^.  59 

little  or  not  at  all  notcht,  except  in  the  midline  behind,  where  there  is  a  slight  excavation. 
In  the  nearly  smooth  hinder  border  this  genus  differs  from  the  species  oi Ba'ena. 

Most  of  the  sutures  and  of  the  epidermal  sulci  are  obscure;  and  in  most  parts  of  the  cara- 
pace the  sutures  are  incapable  of  determination.  The  sulci  bounding  the  second,  third,  and 
fourth  vertebral  scutes  are  satisfactorily  seen.  These  scutes  were  very  broad,  each  about  34 
mm.;  while  the  costal  scutes  were  only  about  half  as  wide.  The  areas  occupied  by  the  median 
scutes  are  conspicuously  sculptured.  The  sculpture,  as  shown  by  the  third  scutal  area,  con- 
sists of  ten  or  twelve  prominent,  sharp,  uneven  ridges,  which  radiate  forward  and  outward 
from  the  middle  of  the  hinder  border  of  the  area.  Evidently  a  somewhat  similar,  but  less  bold, 
sculpture  characterized  the  areas  of  the  costal  scutes;  but  these  surfaces  have  been  injured  so 
that  it  can  not  be  described.    There  is  no  evidence  of  the  presence  of  supramarginal  scutes. 

On  the  left  side  the  costal  and  marginal  plates  are  broken  away.  The  anterior  and 
posterior  buttresses  of  the  plastron  are  thus  revealed;  and  it  is  evident  that  the  anterior  one, 
joining  the  second  costal  plate,  projected  inward  a  considerable  distance,  as  in  Ba'ena,  to  form 
the  anterior  boundary  of  a  lateral  chamber,  whose  posterior  boundary  was  formed  by  the 
hinder  buttress  joining  probably  the  sixth  costal  plate. 

When  the  costal  plates  broke  away,  the  extremities  of  the  third,  fourth,  and  fifth  ribs  were 
left  adhering  in  the  matrix.  These  evidently  past  downward  deeply  against  the  inner  sides  of 
the  corresponding  marginal  plates,  as  in  Chelydra.  Such  was  probably  not  the  condition  in 
Ba'ena.  The  ends  of  the  ribs  are  terete,  not  flat  as  in  most  other  cases.  So  far  as  can  be  deter- 
mined, there  were  no  fontanels  between  the  costal  plates  and  the  marginals. 

Of  the  plastron  (plate  7,  fig.  5)  all  is  present  except  the  epiplastrals,  and  possibly  the 
anterior  part  of  the  entoplastron.  The  plastron  resembles  closely  that  oi  Ba'ena;  but  the  hinder 
lobe  is  not  notcht  posteriorly,  but  rounded.  There  is  a  considerable  fontanel  between  the  inner 
ends  of  the  mesoplastra.  This  may  be  due  to  the  immaturity  of  the  specimen;  but  judging 
from  the  closeness  of  all  the  sutures  of  our  specimen,  and  from  the  fact  that  in  Ba'ena  the  bones 
soon  co-ossify,  it  seems  probable  that  the  fontanel  would  persist  till  a  late  period  of  life. 

The  anterior  as  well  as  the  posterior  lobe  has  a  width  at  the  base  of  36  mm.  The  posterior 
has  a  length  of  30  mm.,  and  the  anterior  was  probably  about  as  long.  The  posterior  lobe 
diminishes  in  width  rather  rapidly  backward.  The  entoplastron  was  unusually  long  and  narrow 
in  its  hinder  portion.  Nothing  can  be  determined  regarding  the  intergular  and  gular  scutes. 
The  mesoplastron  is  narrowed  at  the  inner  end,  as  in  some  species  of  Ba'ena.  Each  is 
traverst  by  the  pectoro-abdominal  sulcus. 

The  bridge  is  30  mm.  wide,  fore  and  aft.  The  inframarginal  scutes  which  covered  the 
bridge  can  not  be  mapt  with  certainty,  but  there  can  be  little  doubt  that  they  were  present  and 
much  like  those  oi  Ba'ena. 

P.  sculpta  may  be  regarded  as  a  form  ancestral  to  the  later  numerous  species  of  Ba'ena 
which  have  been  found  in  Belly  River,  Upper  Laramie,  Puerco,  Bridger  and  Uinta  beds.  Dr. 
Baur  regarded  Glyptops  plicatulus  as  the  forerunner  of  Ba'ena  (Proc.  Acad.  Nat.  Sci.  Phila. 
1891,  p.  421);  but  we  now  find  in  the  same  quarry  from  which  G.  plicatulus  has  been  reported 
a  form  much  nearer  to  Ba'ena  than  is  Glyptops.  It  becomes  evident  that  we  must  go  back  much 
further  to  find  the  common  ancestor  oi  Glyptops  and  Proba'ena. 

Platychelys,  of  the  Upper  Jurassic  of  Solothurn,  Switzerland,  is  closely  related  to  Ba'ena 
and  Proba'ena,  and  has  been  assigned  by  Lydekker  to  the  Pleurosternidae.  It  differs  in  having 
a  more  highly  sculptured  carapace,  supramarginal  scutes,  and  mesoplastrals  which  do  not 
reach  to  the  midline. 

Genus  BAENA  Leidy. 

Shell  firmly  joined  to  the  carapace  by  sutural  union  with  the  lateral  peripherals  and  by 
broad  and  high  axillary  and  inguinal  buttresses.  Hinder  border  of  the  carapace  scallopt,  and 
with  an  extensive  excavation  over  the  tail.  Nuchal  bone  in  contact  with  the  first  neural;  no 
preneural;  no  supramarginal  scutes;  anterior  lobe  of  plastron  not  extended  in  front  of  the 
carapace.  Mesoplastra  large,  with  the  outer  ends  expanded.  Posterior  plastral  lobe  slightly 
emarginated.  Intergulars,  gulars,  and  inframarginals  present.  Skull  broad,  with  the  temporal 
region  extensively  rooft,  the  squamosals  in  contact  with  the  parietals.    Jugal  forming  a  part  of 


6o  FOSSIL  TURTLES   OF   NORTH   AMERICA. 

the  rim  of  the  orbit.    Triturating  surface  of  the  maxilla  furnisht  with  a  prominent  longitudinal 
ridge.    Choanae  opening  on  a  line  joining  the  fronts  of  the  orbits. 

Key  to  Species  of  BaI^na. 
//'.  Judith  River  species. 

1.  Length  of  anterior  lobe  0.60,  its  width  0.82,  of  width  of  bridge;    width  of  hinder  lobe 

0.94  of  width  of  bridge;    entoplastron  longer  than  broad callosa 

2.  Plastron  known  only  from  part  of  anterior  lobe;  the  entoplastron  broader  than  long  .  .  antiqua 
A^.  Laramie  species. 

1.  Length  of  anterior  lobe  0.92,  its  width  i  .00,  of  width  of  bridge;   width  of  hinder  lobe 

1 .  04  of  width  of  bridge hatchert 

2.  Length  of  anterior  lobe  o .  58,  its  length  o .  79,  of  width  of  bridge;  width  hinder  lobe  o ,  75 

of  width  of  bridge marshi 

A  .  Torrejon  species escavada 

A*.  Bridger  species. 

1.  Shell  broad  behind  and  deeply  scallopt;   strongly  sculptured  on  back arenosa 

2.  Not  so  strongly  sculptured;    a  broad  groove  along  the  back riparia 

3.  Shell  oval,  thin;   the  sculpture  broken  up  into  wrinkles;   no  median  groove sima 

4.  Shell  oval;    rounded   behind;    nearly  smooth clara 

A^.  Unita  species emilite 

Baena  callosa  Hay. 

Plate  8,  fig.  i;   teit-figs.  35,  36. 
Baena  callosa,  Hay,  Ann.  Carnegie  Museum,  ill,  1904,  p.  178,  plate  ix,  text-figs,  i,  2. 

This  species  is  based  on  an  incomplete  shell  which  belongs  to  the  Carnegie  Museum,  in 
Pittsburg,  Pennsylvania.  The  number  is  330.  It  was  collected  in  the  year  1903,  by  Mr.  J.  B. 
Hatcher,  in  the  Judith  River  beds  of  Willow  Creek,  Gallatin  County,  Montana. 

The  posterior  fourth  of  the  carapace  is  missing;  and  of  the  anterior  three-fourths,  many  of 
the  peripherals  and  portions  of  the  costals  are  wanting  (text-fig.  35).     The  entire  length  of  the 


Figs.  35  and  36.     Baena  callosa.     Type.      X'. 

35.  Carapace,    c.  5.  i,  c.s.  2,  etc.,  costal  scutes;  v.s.  i,  v.s.  2,  etc.,  vertebral  scutes. 

36.  Plastron,    dfc,  abdominal  scute;  an,  anal  scute;  eM(,  entoplastron;  f/>/,  epiplastron;  /em,  femoral  scute;  g,  gular 

scute;  hum,  humeral  scute;    hyo,  hyoplastron;  hypo,  hypoplastron;  ig,  intergular  scute;  mes,  mesoplastron; 
pec,  pectoral  scute;  xiph,  liphiplastron. 


.16 


BAENID^. 


6i 


shell  was  about  250  mm.;  the  width  something  over  200  mm.  The  sutures  between  the  various 
bones  are  not  obliterated,  but  the  preservation  is  such  that  they  can  not  be  satisfactorily  traced. 
Most  of  the  anterior  border  of  the  nuchal  is  broken  away.  The  thickness  at  the  free  border 
is  6  mm.;  and  this  border  was  rounded  in  section.  The  third  costal  is  much  thickened  for 
the  reception  of  the  axillary  buttress  of  the  plastron,  and  the  fifth  and  sixth  were  similarly 
thickened  for  the  inguinal  buttress.    The  second  costal,  near  its  proximal  end,  is  5  mm.  thick. 

The  surface  of  the  carapace  presents  evidences  of  a  low  ridge  along  the  midline.  On  the 
area  of  the  first  costal  scute  there  is  a  low  elongated  boss;  and  just  in  front  of  it,  near  the  border 
of  the  shell,  is  a  smaller  one.  In  a  complete  shell  there  would  probably  be  found  a  lateral 
carina  on  each  side. 

The  first  vertebral  scute  is  small,  having  probably  a  length  of  less  than  30  mm.  and  a 
width  of  60  mm.  The  second  is  48  mm.  long  and  65  mm.  wide;  the  third,  57  mm.  long  and  75 
mm.  wide.  In  the  original  description  the  figures  indicating  the  widths  of  the  second  and  the 
third  had  exchanged  places.  The  fourth  was  fully  as  long  as  the  third.  The  first  costal 
scute  is  small,  being  about  36  mm.  in  fore-and-aft  extent. 

The  plastron  lacks  the  hinder  extremity  (plate  8,  fig.  i;  text-fig.  36).  The  total  length 
must  have  been  close  to  205  mm.  The  breadth,  measured  on  the  mesoplastra  and  following 
the  curves,  is  186  mm.  The  median  region  is  slightly  concave  as  far  outward  as  a  ridge  which 
joins  the  free  border  of  the  anterior  lobe  with  that  of  the  posterior  lobe.  From  this  ridge  the 
lower  surface  slopes  upward  and  outward  to  the  outer  borders  of  the  plastral  bones.  The 
bridge  has  a  fore-and-aft  extent  of  87  mm.  The  anterior  lobe  is  short  and  narrow,  the 
length  being  52  mm.;  the  width  at  the  base,  72  mm.;  at  the  hinder  ends  of  the  epiplastra,  38 
mm.  The  latter  bones  are  small,  and  they  meet  along  the  midline,  in  front  of  the  entoplastron, 
only  5  mm.  The  entoplastron  is  relatively  large,  the  length  being  28  mm.;  the  width,  17  mm. 
Seen  from  the  upper  surface,  this  bone  is  broadly  spear-shaped,  with  an  anteriorly  directed 
process,  a  longer  one  directed  backward,  and  a  right  and  a  left  process.  Its  length  on  this 
upper  surface  is  33  mm.  The  free  borders  of  the  anterior  lobe  are  rounded  in  section.  The 
thickness  of  its  various  bones  is  about  7  mm. 

On  the  upper  surface  of  this  plastron  there  is  a  low  ridge  passing  from  one  axillary  buttress 
to  the  other,  making  the  thickness  of  the  bone  at  the  midline  9  mm.  A  similar  thickening  of  the 
bones  is  found  between  the  inguinal  buttresses,  the  thickness  becoming  1 1  mm. 

The  mesoplastral  sutures  are  distinct  everywhere  except  near  the  midline  in  front  of  the 
right  mesoplastron.  The  left  mesoplastron  is  21  mm.  wide  at  the  midline  and  apparently  43 
mm.  at  the  outer  end.    The  mesoplastron  of  the  right  side  is  only  36  mm.  wide  at  the  outer  end. 

The  posterior  lobe  is  83  mm.  wide  at  the 
base.  It  is  flat  below.  On  the  upper  surface 
there  is  a  thickening  parallel  with  the  free  border 
on  each  side.  From  the  summit  of  the  ridge  thus 
formed  the  surface  slopes  to  the  acute  border 
and  toward  the  midUne.  Just  behind  the  inguinal 
notch  the  thickness  of  the  bone  is  14  mm.;  where 
the  hypoxiphiplastral  suture  crosses  the  midline, 
only  4  mm.  thick. 

The  sulci  are  in  general  distinctly  developt.  Those  behind  the  intergular  are  somewhat 
obscure.  The  intergulars  do  not  separate  the  gulars.  The  various  scutes  meet  their  fellows 
along  the  midline  as  follows:  Intergulars,  12  mm.;  gulars,  9  mm.;  humerals,  32  mm.; 
pectorals,  41  mm. ;  abdominals  27  mm.;  femorals,  40  mm.  The  length  of  the  anals  is  indeter- 
minable. They  lie  partly  on  the  hypoplastral  bones.  On  each  bridge  there  are  3  inframar- 
ginals,  whose  outer  borders  rested  on  the  bridge  peripherals. 

The  table  herewith  is  intended  to  present  the  most  obvious  differences  in  the  proportions 
of  the  plastral  bones  in  the  three  species,  B.  hatcheri,  B.  marshi,  and  B.  callosa.  The  width  of 
the  bridge  is  taken  as  the  unit. 

It  is  seen  that  B.  hatcheri  has,  relatively  to  the  width  of  the  bridge,  large  anterior  and 
posterior  lobes;  that  B.  marshi  has  both  lobes  small;  and  that  B.  callosa  has  the  anterior 
lobe  short  and  of  moderate  width,  while  the  hinder  lobe  is  broad  at  the  base. 


Dimensions. 

Baena 
hatcheri. 

Baena 
marshi. 

Baena 
callosa. 

Width  of  bridge 

Length  of  anterior  lobe 
Width  of  anterior  lobe . 
Width  of  hinder  lobe. . 

1. 00 

.91 

1.00 

1.04 

1.00 

.58 
•79 
•75 

I/X> 

.60 
.82 
•94 

62 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


The  anterior  lobe  of  the  present  species  is  narrower  and  more  pointed  than  that  described 
by  Lambe  (Cent.  Canad.  Palaeont.,  iii,  1902,  p.  44,  figs.  10,  a,  b)  under  the  name  B.  antiqua. 

Baena  antiqua  Lambe. 

Text-figs.  37,  38. 

Baena  antiqua,  Lambe,  Contrib.  Canad.  Palasont.,  fll,  1902,  p.  44,  figs.  10,  a,  b. 

The  materials  on  which  this  species  was  based  belong  to  the  Canadian  Geological  Survey. 
They  were  collected  in  1901,  in  the  Judith  River  beds,  on  Red  Deer  River,  British  America,  by 

Mr.  L.  M.  Lambe,  of  the  Canadian  Survey.  The  type  of  the  species 
consists  of  the  median  region  of  the  anterior  two-thirds  of  the  cara- 
pace. Near  it  was  found  the  greater  part  of  the  anterior  lobe  of 
the  plastron,  and  this  is  believed  to  belong  to  the  same  individual. 
The  front  of  the  carapace  (fig.  37)  was  apparently  broad 
and  rounded.  The  nuchal  bone  is  28  mm.  fore  and  aft;  58 
mm.  from  side  to  side.  The  neurals  are  irregular  in  form  and 
outlines.  The  vertebral  scutes  are  broader  than  long.  The 
dimensions  of  the  three  present  are  given  in  the  accompanying  table. 

No  supernumerary  costal  appears  on  each  side  of  the  first  vertebral,  such  as  is  found  in 
many  species  of  the  genus. 

The  fragment  of  plastron  (fig.  38)  presents  an  entoplastron  that  differs  from  all  others  at 
present  known  in  being  lozenge-shaped  and  broader  than  long.  Its  length  is  22  mm.;  its 
breadth,  28  mm. 


■  VertebraL 

Length. 

Width. 

I 

40 

73 

z 

62 

70 

3 

66 

75 

Fig.  37. — Baena  antiqua.    Carapace.     Type.    X§.     Reduced  from  Lambe's  original  drawing. 

bones;  n.  i,  etc.,  neural  bones;  nu.  p.  nuchal  bone. 
Fig.  38. — Baena  antiqua.    Anterior  lobe  of  plastron.     XJ.     From  drawing  by  Lambe. 
Fig.  39. — Baena  marshi.    Plastron  of  type.    X/o- 


etc.,  costal 


Baena  marshi.  Hay,  Amer.  Jour.  Sci. 


Baena  marshi  Hay. 
Plate  8,  fig.  2;   text-fig.  39. 
xviii,  1904,  p.  261,  plate  xi,  text-fig.  i. 


The  type  and  only  known  specimen  of  this  species  comes  from  the  Laramie  deposits  of 
Wyoming.  It  was  collected  in  1889,  by  Professor  J.  B.  Hatcher,  in  Converse  County,  between 
Buck  and  Lance  Creeks,  and  is  now  in  the  Yale  University  Museum. 

The  specimen  is  considerably  damaged.  There  are  present  the  cast  of  the  greater  portion 
of  the  interior  of  the  shell,  the  greater  part  of  the  central  portion  of  the  carapace  and  most  of  the 


BAENID^. 


63 


Dimensions. 

Baina 
marshi. 

Baena 
hatcheri. 

Length  of  plastron 

Width  of  the  bridge 

Length  of  anterior  lobe .  . 
Width  of  anterior  lobe. . . 
Length  of  hinder  lobe . . . 
Width  of  hinder  lobe 

260  ± 
110 

70 

65  ± 
90 

305 
"5 
106 

"i      ! 
98 

IXO 

left  side,  and  a  large  part  of  the  plastron.  The  length  of  the  carapace  is  conjectural,  but  it 
appears  to  have  been  at  least  300  mm.  The  width  was  220  mm.  Its  composition  can  not  be 
determined,  since  the  bones  have  co-ossified  and  obliterated  the  sutures.  In  the  median  region 
the  bones  reach  a  thickness  of  from  10  to  13  mm.  The  outer  surface  is  smooth.  The  sulci  are 
narrow  and  shallow,  and  in  most  places  are  not  traceable.  The  second,  third,  and  fourth 
vertebral  scutes  varied  from  65  to  70  mm.  in  width.  The  first  and  fifth  were  probably  somewhat 
wider. 

The  hinder  extremity  of  the  plastron  (plate  8,  fig.  2;  text-fig.  39)  is  missing,  so  that  its 
form  can  not  be  determined.     The  anterior  lobe  has  the  right  border  nearly  complete  to 

beyond  the  midline  in  front,  so  that  its  form  is  known. 
The  dimensions  of  the  plastron  are  shown  in  the 
accompanying  table.  In  order  that  the  distinctness  of 
the  species  from  B.  hatcheri  may  be  seen,  the  dimensions 
of  the  latter  are  added. 

The  plastron  is  somewhat  concave.  The  concavity 
extends  laterally  to  a  rounded  ridge  which  runs  from  the 
outer  border  of  the  anterior  lobe  to  the  outer  border 
of  the  posterior  lobe.  From  this  ridge  the  outer  ends 
of  the  hyoplastron  and  hypoplastron  extend  upward 
and  outward  to  the  peripherals,  and  the  elevation  is 
continued  on  the  latter  to  the  carina  which  unites  the  free  borders  of  the  third  and  the  seventh 
peripherals.  From  the  midline  of  the  plastron  to  the  ridge  is  55  mm.;  from  the  ridge  to  the 
lateral  carina  is  about  85  mm.,  the  measurements  being  taken  on  the  mesoplastron. 

Most  of  the  sutures  of  the  plastron  may  be  traced.  The  limits  of  the  entoplastron  are 
not  determinable;  nor  have  the  sutures  between  the  xiphiplastra  and  the  hypoplastra  been 
observed.  The  mesoplastra  meet  along  the  midline  for  about  23  mm.  while  their  outer  ends  are 
65  mm.  wide.  The  sutures  between  the  plastral  bones  and  the  bridge  peripherals  are  distinctly 
shown.  The  whole  width  of  the  plastron,  on  the  mesoplastra,  and  following  the  curves,  is 
215  mm. 

The  gular  scutes  appear  to  have  met  for  some  distance  along  the  midline.  The  gulo- 
humeral  sulcus  runs  nearly  directly  across  the  lobe  and  meets  the  median  line  27  mm.  behind 
the  anterior  border.  The  following  are  the  antero-posterior  dimensions  of  the  various  plastral 
scutes,  measured  along  the  midline:  Intergulars,  17  mm.;  gulars,  10  mm.;  humerals,  46  mm.; 
pectorals,  50  mm.;  abdominals,  47  mm.;  femorals,  53  mm.;  anals,  45  mm.  On  the  bridge 
there  are  4  inframarginals,  of  which  the  inguinal  is  the  largest,  and  the  axillary  somewhat  the 
smallest.    The  outer  borders  of  these  overlap  on  the  bridge  peripherals. 

This  species  appears  to  differ  from  Baena  hatcheri  in  the  smaller  plastron,  the  longer 
bridge,  and  the  greater  thickness  of  the  bones  of  the  carapace,  especially  of  the  dorsal  region. 
It  is  named  in  honor  of  Professor  O.  C.  Marsh,  formerly  professor  of  vertebrate  paleontology 
in  Yale  University. 

Baena  hatcheri  Hay. 

Plates  9,  10;   text-6gs.  40,  41. 

Baena  hatcheri,  Hay,  Ann.  Carnegie  Museum,  i,  1901,  p.  325,  plate  xv. — Hatcher,  Bull.  U.  S.  Geol. 
Surv.  No.  257,  p.  79. 

The  type  of  the  species  is  a  very  complete  shell  which  was  collected  by  Mr.  J.  B.  Hatcher, 
in  the  year  1900,  in  the  Ceratops  beds  of  the  Laramie  formation,  in  Converse  County, 
Wyoming.  The  locality  given  more  particularly  is  a  sandstone  bluff  on  the  south  side  of 
Lance  Creek,  opposite  the  mouth  of  Dolgie  Creek.  The  specimen  belongs  to  the  collection 
of  the  Carnegie  Museum. 

The  whole  plastron  is  present  and  all  of  the  carapace  except  a  small  portion  of  the  rear. 
The  sides  of  the  carapace  are  somewhat  crusht  in,  and  some  crushing  has  been  suffered  by  the 
bridge  peripherals;  but  these  defects  do  not  stand  in  the  way  of  determining  the  characters  of 
the  species.  It  displays  all  the  epidermal  sulci  and  nearly  all  of  the  bone  sutures.  Moreover, 
the  matrix,  a  soft  sandstone,  has  been  removed,  so  that  the  interior  too  can  be  observed. 


64 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


The  total  length  of  the  carapace  (plate  9)  was  originally  368  mm.;  the  total  breadth, 
280  mm.;  the  height  from  the  bottom  of  the  plastron,  about  145  mm.  The  greatest  breadth 
of  the  carapace  was  somewhat  behind  the  inguinal  notches.  From  here  the  border  rounds 
rapidly  to  the  median  excavation  behind.  The  anterior  end  is  rather  pointed.  In  front,  the 
margin  of  the  carapace  is  unbroken  by  serrations  or  sinuses,  except  that  the  nuchal  is  slightly 
excavated.  The  hinder  portion,  from  the  inguinal  notches  backward,  is  scallopt  as  in  the 
other  species  of  the  genus.  It  is  also  thin  and  rather  acute.  Even  at  the  bridges  the  border  was 
narrowly  rounded. 


Fig.  40. — Ba'ena  hatcheri.     Type. 
Xj.     Carapace. 


Fig.  41. — Ba'ena  hatcheri.     Type 
Xj.     Plastron. 


The  sutures  between  the  bones  are  fine  and  their  course  is  often  indicated  by  only  the 
finely  striated  border  of  the  adjoining  bone. 

The  nuchal  bone  is  nearly  quadrate  in  form.  It  is  43  mm.  long  fore  and  aft,  with  a  width 
ot  59  mm.  in  front  and  a  maximum  width  of  72  mm.  The  neurals  in  general  are  hexagonal, 
with  the  broader  end  forward.    The  table  annext  presents  the  dimensions  of  the  neurals. 

The  single  suprapygal  had  a  length  of  50  mm.  and  a  width  of  56  mm.  No  true  pygal  is 
interposed  between  the  peripherals  of  the  last  pair. 

The  costal  plates  vary  considerably  in  the  fore-and-aft  extent.  Measured  at  their  proximal* 
ends  they  have  the  following  widths :  First,  48  mm.;  second,  40 
mm.;  third,  47  mm.;  fourth,  33  mm.;  fifth,  47  mm.;  sixth,  32  mm.; 
seventh,  32  mm.;  eighth,  31  mm.  The  fifth  costal  presents  the 
peculiarity  of  being  very  narrow  at  the  distal  end — only  9  mm. 
The  peripherals  are  high,  the  first  two  about  38  mm.;  the 
third,  33  mm.;  the  next  three,  about  52  mm.;  the  seventh,  eighth, 
ninth,  about  68  mm.;  the  tenth,  eleventh,  and  twelfth,  about 
48  mm.  The  sutures  between  the  peripherals  behind  the  eighth 
are  not  visible,  but  they  were  probably  not  far  removed  from  the 
lines  representing  them. 

The  epidermal  scutes  are  all  defined   by  sulci   which    are 


NeuraL 

Length. 

Width. 

I 

40 

40 

2 

36 

30 

3 

5' 

36 

4 

3S 

33 

5 

47 

33 

6 

36 

3^ 

7 

3^ 

28 

8 

^3 

3°        , 

BAENID^. 


65 


distinct,  but  very  narrow  and  shallow.  The  vertebrals  are  relatively  wider  than  they  are  in  any 
of  the  other  species  of  the  genus.  From  the  first  vertebral  there  is  cut  off  on  each  side  an  acces- 
sory lateral  scute,  and  this  has  much  reduced  its  size;  also,  from  its  anterior  end  there  is  cut  off 
a  small  supernumerary  vertebral,  so  that  there  are  really  6  vertebrals,  as  in  Chisternon.  The 
table  herewith  gives  the  dimensions  of  the  vertebrals.  The  width  of  the  central  ones  is  really 
somewhat  greater  than  the  figures  indicate,  on  account  of  some  lateral  compression. 

The  triangular  supernumerary  lateral  scutes  are  each  39  mm.  fore  and  aft,  and  50  mm. 
from  side  to  side. 

The  area  usually  occupied  in  turtles  by  the  nuchal  scute  is  broken  up  into  4  scutellae 
unsymmetrical  in  form  and  size.  Of  these  the  extreme  right  and  left  are  larger  and  much 
alike  in  form  and  size;  the  median  two  are  much  unlike,  one  being  very  small. 

Behind  the  nuchal  scutellae  there  are  13  marginals  on  each  side.  Usually  the  costo-marginal 
sulci  run  along  some  distance  below  the  costo-peripheral  sutures.  The  first  marginal  extends 
back  from  the  border  of  the  shell  only  16  mm.;  the  fourth,  40  mm.;  the  sixth,  55  mm.,  and 
rises  above  the  costo-peripheral  suture;  the  eighth,  53  mm.;  the  eleventh,  41  mm.  The  thir- 
teenth is  considerably  smaller  than  the  twelfth.  As  in  other  species  of  Baena,  there  was  no 
supracaudal  scute. 

The  plastron  (plate  10)  is  rather  narrow,  especially  the  hinder  lobe.  Its  total  length  is 
305  mm.  The  bridge  has  a  width,  fore  and  aft,  of  1 15  mm.;  a  length,  from  the  inner  end  to  the 
border  of  the  carapace,  of  95  mm.  It  rises  considerably  from  the  inner  end  to  the  outer.  The 
anterior  lobe  is  106  mm.  long;  1 15  mm.  wide  at  the  base.  The  width  diminishes  gradually  to 
the  gulo-humeral  sulcus,  then  rapidly  to  the  midline  in  front.  The  thickness  of  the  border  of 
the  lobe  is  about  8  mm.;  behind  the  entoplastron,  about  6  mm. 

The  hinder  lobe  is  98  mm.  long;  120  mm.  wide  at  the  base.  The  lateral  borders  are 
nearly  straight  and  convergent  to  the  ends  of  the  femoro-anal 
sulcus.  Here  the  width  is  71  mm.  Behind  this,  the  sides  are 
nearly  parallel  for  a  short  distance;  then  they  round  rapidly  to 
the  shallow  hinder  excavation..  Just  behind  the  inguinal  notch 
the  thickness  is  18  mm.;  near  the  hinder  extremity,  only  7  mm. 
The  entoplastron  is  oval,  47  mm.  long  and  36  mm.  wide. 
The  hyoplastrals  extend  along  the  midline  85  mm.,  and  each 
reaches  laterally,  behind  the  axillary  notch,  105  mm.  There  are 
large  mesoplastrals.  The  median  ends  are  24  mm.  wide,  the 
lateral  ends,  61  mm.  Each  extends  outward  from  the  midline 
125  mm.  The  hypoplastrals  join  along  the  midline  for  the  distance  of  75  mm.;  the  xiphi- 
plastrals,  60  mm. 

The  intergulars  and  gulars  are  of  about  the  same  form  and  size,  all  starting  from  a  point 
near  the  front  of  the  entoplastron.  The  humerals  are  63  mm.  long  and  meet  for  some  distance 
behind  the  entoplastron.  The  pectorals  occupy  about  54  mm.  of  the  midline;  the  abdominals, 
about  48  mm.;  the  femorals,  about  78  mm.;  the  anals,  37  mm. 

On  the  bridge  of  each  side  are  seen  4  large  inframarginals.  These  lie  principally  on  the 
plastral  bones,  but  partly  on  the  peripherals. 

The  hyoplastra  and  hypoplastra  send  upward  strong  buttresses  against  the  inner  surfaces 
of  the  first,  and  of  the  fifth  and  sixth  costals  respectively;  but  these  buttresses,  especially  the 
inguinal,  do  not  extend  inward  so  far  as  they  do  in  the  other  species  of  the  genus.  The  axillary 
buttress  is  directed  upward  and  forward  toward  the  front  of  the  first  dorsal  vertebra.  Its 
inner  border  is  acute.  At  its  upper  end  the  buttress  joins  the  first  rib,  which  is  wide  and  fur- 
nisht  with  a  sharp  border;  thus  the  partition  bounding  the  sternal  chamber  anteriorly  is 
carried  up  to  the  first  dorsal  vertebra.  The  inguinal  buttress,  seen  from  behind,  appears  to  be 
about  30  mm.  wide;  but  in  front  of  it  the  sternal  chamber  extends  far  out  toward  the  border  of 
the  carapace. 

Baena  escavada  sp.  nov. 
Plate  II,  figs.  I,  2;  text-figs.  42,  43, 

The  chelonite  on  which  this  species  is  based  was  obtained  by  Dr.  J.  L.  Wortman  and  Mr. 
Walter  Granger  in  1896,  in  the  Torrejon  deposits,  at  the  head  of  Escavada  Creek,  in  New 

5 


Vertebral. 

Length. 

Width. 

, 

>9 

3* 

z 

50 

83 

3 

75 

90 

4 

80 

90 

5 

90 

'' 

6 

" 

88 

66 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


Mexico.  The  specimen  is  not  quite  complete,  being  somewhat  crusht  and  fractured  and 
having  a  portion  of  the  margin  of  the  left  side  missing. 

The  species  closely  resembles  the  others  of  the  genus,  but  possesses  sufficiently  distinctive 
characters.  The  specific  name  is  that  of  the  stream  near  which  the  specimen  was  found.  The 
catalog  number  is  1203,  of  the  American  Museum  of  Natural  History. 

All  traces  of  the  sutures  between  the  bony  elements  of  the  shell  are  obliterated  thru  co- 
ossification.  The  sutures  between  the  epidermal  scutes  are  distinct,  but  narrow  and  only 
moderately  imprest.  The  total  length  of  the  carapace  (plate  1 1,  fig.  i ;  text-fig.  42)  is  381  mm. 
In  the  midline  the  length  is  about  12  mm.  less,  on  account  of  the  slight  emargination  in  front 
and  the  excavation  in  the  rear.  The  breadth  was  close  to  300  mm.  The  carapace  is  broad, 
ovate,  obtusely  pointed  in  front,  truncate  behind.  On  each  side  of  the  anterior  emargination 
the  border  was  gently  repand.  The  hinder  border,  on  each  side  of  the  excavation  for  the  tail, 
was  scallopt.  On  the  hindermost  part  of  the  carapace  there  is  a  moderate  rounded  keel.  From 
this  there  may  be  traced  forward  faint  indications  of  the  two  parallel  grooves  so  distinct  in 
B.  arenosa.     Except  these  grooves,  the  ornamentation  seen  in  the  latter  species  is  absent. 


43- 


Figs.  42  and  43. — Ba'ena  escavada.     Type.      xj.     Form  of  shell  and  the  scute  areas. 


42.  Carapace. 


43.  Plastron. 


The  most  distinctive  character  of  this  species  is  seen  in  its  narrow  and  spatulate  anterior 
plastral  lobe  (plate  11,  fig.  2;  text-fig.  43).  The  plastron  as  a  whole  is  relatively  small.  The 
total  length  is  295  mm.  The  anterior  lobe  has  a  length  of  83  mm.  and  a  breadth,  at  its  base,  of 
96  mm.  From  the  base  the  lateral  borders  run  forward  and  inward  to  within  30  mm.  of  the 
front,  at  the  ends  of  the  sutures  between  the  gular  and  humeral  scutes.  Here  the  width  is  61 
mm.  Beyond  these  points  the  lobe  expands  again  to  64  mm.;  then  curves  forward  and  inward 
to  the  ends  of  the  intergular  sutures.  The  extreme  end  of  the  lobe  is  truncated  and  falls  about 
30  mm.  short  of  the  anterior  border  of  the  carapace. 

The  posterior  lobe  has  a  width  of  114  mm.  at  the  base  and  a  length  of  75  mm.,  failing  to 
reach  the  excavation  in  the  carapace  by  about  47  mm.  It  narrows,  as  it  passes  backward,  more 
rapidly  than  does  that  of  B.  arenosa.    The  hinder  border  is  slightly  concave. 

The  bridge  has  a  width  of  135  mm.    Its  length,  to  outer  margin  of  the  shell,  is  105  mm. 


BAENID^.  67 

The  vertebral  scutes  are  relatively  narrow,  the  second  having  a  length  of  88  mm.  and  a  width 
of  65  mm.;  the  third  a  length  of  85  mm.  and  a  width  of  about  70  mm.;  the  fourth  a  length  of 
80  mm.  and  a  width  of  70  mm.;  the  fifth  a  length  of  48  mm.  and  a  width  of  80  mm.  In  the 
case  of  the  first  vertebral  the  same  lack  of  symmetry  is  to  be  seen  as  has  been  observed  in  so 
many  other  specimens  belonging  to  the  genus  Ba'ena. 

The  costo-marginal  sulci  are  distant  from  the  edge  of  the  carapace  about  22  mm.  Those 
subdividing  this  anterior  marginal  region  are  too  obscure  for  certain  determination.  There 
are  indications  of  one  which  crost  this  region  about  15  mm.  to  the  left  of  the  midline.  There 
was,  therefore,  probably  a  nuchal  scute  30  mm.  long  from  side  to  side.  Beyond  this  the 
marginals  increase  in  length  and  breadth.  Over  the  bridge  they  rise  on  the  sides  of  the 
carapace  45  mm. 

On  the  plastron  are  distinct  gulars  and  intergulars.  The  humero-pectoral  sulcus  crosses  the 
midline  on  the  line  joining  the  axillary  notches.  Laterally  the  sulcus  is  suddenly  turned  forward 
and  outward.  The  pectoral  scutes  meet  along  the  midline  for  a  distance  of  53  mm.,  and  extend 
laterally  about  72  mm.  The  abdominal  scutes  occupy  52  mm.  of  the  midline;  the  femorals  67 
mm.;  the  anals  50  mm.  As  in  other  species  of  Ba'ena,  the  suture  between  the  femorals  and  the 
anals  runs  outward,  then  turns  backward  for  some  distance,  then  again  outward. 

There  are  4  large  inframarginals. 

Baena  arenosa  Leidy. 
Plate  12;  plate  13,  fig.  i;  plate  14,  figs.  1-3;  teit-figs.  44-51. 

Baena  arenosa,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1870,  p.  123;  U.  S.  Gaol.  Surv.  Wyoming,  etc., 
1870  (1871),  p.  367;  U.  S.  Gaol.  Surv.  Montana,  ate,  1871  (1872),  p.  368;  Contrib.  Ext.  Vart. 
Fauna  W.  Tarrs.,  1873,  pp.  161,  343,  pi.  xiii,  figs.  1-3;  .'pi.  xv,  figs.  1-5;  pi.  xvi,  figs.  8,  9. — Cope, 
.'Append.  LL  of  Ann.  Report  Chief  of  Engineers,  1875,  p.  96;  .'Wheeler's  Surv.  looth  Merid., 
'877.  P-  52,  pl-  xxiv,  fig.  32. — Baur,  Proc.  Acad.  Nat.  Sci.  Phila.  1891,  p.  426,  fig. — Hay, 
Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  437. 

Baena  afflnis,  Leidy,  Ann.  Report  U.  S.  Gaol.  Surv.  Wyoming,  etc.,  1870  (1871),  p.  367. 

Baena  arenosa,  the  type  of  the  genus  Baena,  was  based  on  a  shell  lacking  only  the  anterior 
lobe  of  the  plastron  and  the  anterior  border  of  the  carapace.  This  specimen  is  now  in  the 
United  States  National  Museum  at  Washington.  It  was  figured  and  described  at  length  in  Dr. 
Leidy's  work  of  1873.  The  specimen  was  obtained  in  the  Bridger  deposits,  at  the  junction  of 
the  Big  Sandy  and  Green  Rivers,  in  southwestern  Wyoming.  These  beds  are  regarded  as 
belonging  to  the  lowermost  of  the  Bridger  formation. 

The  specimen  described  by  Leidy  evidently  had  originally  a  length  of  close  to  340  mm.  and 
a  width  of  288  mm.  The  rear  of  the  carapace  is  broadly  rounded.  The  vertebral  scutes  are 
broader  than  long.  The  hinder  lobe  of  the  plastron  is  broad  and  it  narrows  slowly  backward. 
The  width  of  the  anterior  lobe,  taken  from  the  outer  ends  of  the  humero-pectoral  sulci,  equals 
half  the  length  of  the  plastron  behind  this.  Dr.  Leidy  states  that  the  position  of  the  former 
sutures  can  not  be  detected.  This  is  true  as  regards  the  outer  surface  of  the  bones;  but  on  the 
upper  side  of  the  plastron  the  sutures  on  each  side  of  the  mesoplastrals  are  to  be  observed. 
The  left  mesoplastron  had  a  width  of  about  25  mm.  at  the  midline;  that  on  the  right  side  was 
narrower. 

A  portion  of  the  pelvis  and  the  sacral  vertebrae  and  ribs  of  this  specimen  were  figured  by 
Dr.  Leidy.  Later,  Dr.  Baur  obtained  from  the  matrix  of  the  specimen  additional  parts  of  the 
pelvis  and  briefly  described  them.  While  some  parts  are  still  wanting  there  is  enough  to  show 
that  the  ischia  were  united  with  the  pubes  along  the  midline  and  that  the  pubes  extended  at 
least  35  mm.  in  front  of  their  hinder  border  at  the  midline  (figs.  44,  45).  The  upper  end  of 
the  ilium  was  expanded  backward.  The  width  of  this  expanded  part  was  equal  to  the  height, 
35  mm. 

The  writer  follows  Dr.  Leidy  and  Professor  Cope  in  identifying  the  former's  B.  afpnis  as 
the  earlier  described  B.  arenosa.  The  original  description  of  5.  affinis  was  exceedingly  brief  and 
hesitating.  It  was  supposed  to  be  distinct  from  B.  arenosa  because  of  the  presence  of  only 
3  inframarginals.  In  Leidy's  next  reference  to  the  species,  he  referred  it  to  his  earlier  B. 
arenosa.     The    type    is    now    in    the    collection    of    the    Philadelphia    Academy.      It    was 


68 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


obtained  at  Church  Buttes,  in  the  level  known  as  B.  Dr.  Leidy's  figure  makes  the  anterior 
lobe  of  the  plastron  appear  too  short  and  too  narrow.  The  plastron  has  a  total  length  of  275 
mm.  The  anterior  lobe  is  75  mm.  long  and  70  mm.  wide  at  the  base.  The  bridge  has  a  width 
of  123  mm.  The  hinder  lobe  is  "JJ  mm.  long  and  1 10  mm.  wide  at  the  base.  The  carapace  has 
a  length  of  300  mm.  in  a  straight  line.    The  surface  is  uneven,  especially  within  the  areas  of  the 

vertebral  scutes.  There  appear  to  have  been  no  supernumer- 
ary costal  scutes.  The  dimensions  of  the  vertebrals  are  given 
in  the  accompanying  table. 

The  American  Museum  expedition  of  1903  collected  a 
number  of  specimens  which  must  be  referred  to  this  species. 
The  most  important  of  these  is  No.  5973,  collected  at  Grizzly 
Buttes,  Wyoming.  It  furnishes  a  somewhat  damaged  shell; 
the  skull,  lacking  the  left  side  and  the  lower  jaw;  a  portion  of 
the  shoulder-girdle;  the  humerus,  lacking  the  distal  end;  and 
the  ulna.  The  length  of  the  carapace  (plate  12)  in  a  straight 
line  is  330  mm.,  to  the  bottom  of  the  posterior  notch,  320  mm.; 
its  width,  about  315  mm.  The  bones  are  thoroly  co-ossified 
and  the  sutures  obliterated.  The  anterior  border  projects  somewhat  at  the  midline.  The  pos- 
terior border  is  broad,  with  a  median  excavation  60  mm.  wide  and  lateral  scallops. 

48. 


Verte- 
bral. 

Type  of  B. 
affinis. 

No.  5973 
A.  M.  N.  H. 

Length.  Width. 

Length.  Width. 

2 
3 

4 
5 

50           72 
73          (" 
73     '     64 
60           b3 

55     ,     75 

48            60 

72           67 
77      '     74 
62           69 

57           77 

46. 


44- 


47- 


Figs.  44-48. — Baena  arenosa.     No.  5973  A.  M.  N.  H. 


44.  Pelvis  seen  from  left  side.     XS. 

45.  Left  half  of  pelvis  seen  from  below. 

46.  Plastron.     Xj. 


x«. 


47.  Left  humerus.     X§. 

48.  Right  ulna.     XS- 


On  each  side  of  the  first  vertebral  there  is  a  small  supernumerary  costal  scute.  Along  the 
midline  there  is  a  narrow  ridge  and  within  the  areas  of  the  vertebral  scutes  a  number  of  sym- 
metrically arranged  ridges.      The  dimensions  of  the  vertebrals  are  given  in  the  table  above. 

The  plastron  (plate  13,  fig.  i;  text-fig.  46)  is  287  mm.  long.  The  anterior  lobe  is  ■/'/  mm. 
long;  104  mm.  wide  at  the  base;  and  jy  mm.  at  the  gulo-humeral  sulcus.  The  limits  of  the 
entoplastron  can  not  be  traced.    The  bridge  is  125  mm.  wide.    By  means  of  the  striations  on  the 


BAENID^.  69 

bones  the  limits  of  the  mesoplastrals  can  be  pretty  well  determined.  They  appear  to  have 
joined  each  other  at  the  midline  for  a  distance  of  about  25  mm.  The  hinder  lobe  is  84  mm. 
long;  114  mm.  wide  at  the  base;  and  92  mm.  wide  at  the  gulo-humeral  sulcus.  At  the  rear 
there  is  a  broad  and  shallow  notch.  The  plastral  scutes  offer  no  especial  deviations  from  the 
normal.  Their  forms  and  dimensions  may  be  determined  from  the  figure.  On  each  of  the 
bridges  there  are  3  inframarginals. 

The  right  humerus  (fig.  47)  lacks  the  distal  end.  Its  length  has  been  approximately  70  mm. 
The  resemblance  to  that  oiChelydra  is  close.  The  head  is,  however,  not  so  large,  and  especially 
it  is  comprest  in  a  plane  perpendicular  to  the  dorsal  surface  of  the  bone.  Furthermore,  the 
plane  of  this  comprest  head  inclines  to  the  radial  side  of  the  humerus;  whereas,  in  Chelydra, 
it  falls  far  outside  of  the  ulnar  side.  The  ulnar  and  radial  processes  are  large  and  the  distance 
from  the  outside  of  one  to  the  outside  of  the  other  measures  32  mm.  In  the  case  of  the  humerus 
of  the  type  of  B.  rtparia  this  distance  is  only  26  mm.  In  B.  arenosa,  as  well  as  B.  riparia,  the 
planes  of  the  two  processes  are  at  right  angles  with  each  other,  as  in  Chelydra.  The  processes 
are  much  thicker  than  in  Chelydra.  The  shaft  has  a  diameter  of  8.25  mm.  The  groove 
leading  to  the  ectepicondylar  foramen  is  broad  and  deep.  A  fragment  from  near  the  distal  end 
of  the  left  humerus  has  a  width  of  21.5  mm.  The  right  ulna  (fig.  48)  is  present.  The  shaft  is 
not  flattened  like  that  of  the  Cryptodira,  but  is  nearly  cylindrical,  like  that  of  Hydromedusa. 
The  articulation  for  the  humerus  is,  however,  like  that  of  the  Cryptodira.  The  bone  is  52  mm. 
long;  15  mm.  wide  at  the  distal  end. 

Plate  14,  figs.  1-3,  represents  what  is  left  of  the  skull.  The  occipital  condyle  and  the 
premaxillae  are  wanting,  but  the  length  between  these  two  was  close  to  60  mm.  The  greatest 
width  (plate  14,  fig.  i)  just  in  front  of  the  tympanic  cavities  was  62  mm.  From  the  tips  of  the 
nasals  to  the  extremity  of  the  supraoccipital  is  57  mm.  All  the  sutures  of  the  roof  of  the  skull 
are  obliterated.  The  tympanic  cavity  (plate  14,  fig.  2)  has  a  horizontal  diameter  of  15  mm.  and 
a  vertical  of  18  mm.  The  stapedial  rod  remains  in  its  natural  position.  The  eyes  appear  to 
have  lookt  upward  and  outward  more  than  in  Chisternnn  hebratcum  (fig.  78,  p.  89),  and  were 
smaller.  The  orbits  are  circular  with  a  diameter  of  16  mm.  The  interorbital  space  is  22  mm.; 
the  nasal  opening,  20  mm.  wide;  the  maxilla,  below  the  eye,  10  mm.  wide.  Seen  from  below 
(plate  14,  fig.  3),  the  cutting-edge  of  the  maxilla  is  sharp,  thickened  upward  to  5  mm.,  and  at 
least  30  mm.  long.  There  is  a  prominent  ridge  on  the  triturating  surface  of  the  maxilla,  highest 
on  each  side  of  the  choanje.  The  least  width  across  the  pterygoids  is  13  mm.  From  the  outer 
posterior  angle  of  the  basioccipital  bone  a  strong  ridge  runs  forward  toward  the  basisphenoid. 
The  basisphenoid  did  not  come  into  contact  with  the  vomer.  Unfortunately,  the  lower  jaw  is 
missing. 

On  the  upper  side  of  the  skull  are  seen  numerous  anastomosing  grooves,  the  boundaries  of 
horny  scutes  that  covered  most  of  the  upper  surface.  Some  of  these  are  represented  in  fig.  i , 
plate  14. 

The  skull  differs  from  that  of  Chisternon  hebratcum  in  having  a  wider  interorbital  space, 
a  smaller  eye,  and  far  more  prominent  masticatory  ridges  on  the  upper  jaws.  It  is  most  like 
that  o{  B.  riparia.  Unfortunately,  both  skulls  are  damaged,  so  that  full  comparison  is  not  pos- 
sible. The  two  skulls  are  of  almost  exactly  the  same  size.  The  snout  of  5.  arcnoj-a  was  broader, 
as  was  also  the  interorbital  space.  The  eye  of  5.  riparia  appears  to  have  had  a  greater  vertical 
diameter,  but  of  this  we  can  not  be  certain  at  present.  In  B.  rtparia  the  maxilla  below  the  orbit 
is  only  9  mm.  wide.  In  B.  riparia  the  ridge  along  the  junction  of  the  basisphenoid  and  the 
pterygoid  is  far  less  prominent.  In  this  species,  too,  there  is  a  low  ridge  running  from  the  pedicel 
of  the  quadrate  to  meet  the  free  border  of  the  pterygoid.  Another,  starting  from  the  same 
point,  runs  forward  and  upward  along  the  suture  between  the  quadrate  and  the  pterygoid. 
The  surface  of  the  bone  between  these  two  ridges  is  somewhat  scoopt  out.  In  B.  arenosa  the 
ridges  are  little  developt  and  the  space  between  them  is  convex. 

No.  1 1 15  of  the  American  Museum  is  identified  as  belonging  to  the  present  species.  It 
was  collected  by  the  museum's  expedition  of  1893  into  southwestern  Wyoming.  The  locality 
whence  it  was  obtained  is  Laclede  Meadows,  southwest  of  Bitter  Creek  station  and  west  of 
Haystack  Mountain.  The  deposits  belong  to  the  Washakie  formation.  Of  this  individual  the 
front  and  a  part  of  the  right  border  of  the  carapace  (fig.  49)  and  the  front  of  the  anterior  lobe 
of  the  plastron  (fig.  50)  are  missing.    The  remainder  of  the  shell  is  well  preserved.    It  had  origi- 


7° 


FOSSIL   TURTLES    OF    NORTH    AMKRICA. 


nally  a  length  of"  about  395  mm.,  measured  in  a  direct  line.  The  greatest  width,  340  mm.,  is 
across  the  middle  of  the  length  of  the  carapace.  Across  the  axillary  notches  the  width  is  315 
mm.,  and  that  taken  25  mm.  in  front  of  the  hinder  extremity  of  the  plastron  is  306  mm.  It  will 
be  seen  therefore  that  the  extremities  of  the  shell  are  broad.  The  height  of  the  shell  is  now  145 
mm.  but  it  was  doubtless  greater  during  life. 


Figs.  49  and  50. — Baena  arenosa.      Xj.     No.  11 15  A.  M.  N.  H. 

49.  Carapace.    Shows  the  scute  areas.    Front  injured. 

50.  Plastron.    Shows  many  of  the  bones  and  the  scute  areas.    Front  restored. 

The  hinder  border  of  the  carapace  (fig.  49)  is  rather  thin  and  acute,  scallopt  as  in  the 
other  species  of  the  genus,  and  flared  somewhat  upward.    The  anterior  border  is  obtuse.    All 

the  bones  are  thoroly  co-ossified,  so  that  the  forms  of  the  neurals 
can  not  be  determined.  The  surface  is  uneven,  and  especially 
in  the  areas  occupied  by  the  vertebral  scutes  there  are  various 
longitudinal,  transverse,  and  oblique  ridges.  A  slight  depression 
occupies  the  midline  of  vertebrals  3  and  4.  The  accompanying 
table  gives  the  dimensions  of  the  vertebral  scutes.  In  general, 
they  are  wider  than  long. 

As  is  not  infrequent  in  the  species  of  the  genus,  there  are,  on 
the  left  side  at  least,  5  costal  plates.  The  most  anterior  is  cut 
from  the  front  of  the  one  usually  called  the  first;  altho  the  most  anterior  vertebral  is  reduced 
somewhat  in  width  thereby.  The  portion  of  the  rim  of  the  carapace  between  the  outer  border 
of  the  small  anterior  costal  scute  and  the  posterior  vertebral  is  occupied  by  12  marginal  scutes. 
The  plastron  (fig.  50)  has  an  even,  but  granulated,  surface.  The  anterior  lobe  is  133 
mm.  wide  at  the  base.  The  bridges  are  155  mm.  wide.  The  limits  of  the  mesoplastra  are 
indistinctly  discernible.  They  were  about  20  mm.  wide  at  the  midline  and  expanded  distally 
to  about  90  mm.  The  hinder  lobe  is  141  mm.  wide  at  the  base  and  105  mm.  long.  It  dimin- 
ishes in  width  slowly  backward  and  the  end  is  truncated.  At  the  ends  of  the  femoro-anal  sulci 
the  width  is  yet  113  mm.  The  lobe  lacks  about  60  mm.  of  reaching  backward  to  the  hinder 
border  of  the  carapace. 


Vertebral. 

Length. 

Width.    \ 

I 

73 

2 

96 

9' 

.    3 

90 

9S 

4 

80 

9° 

S 

75 

100 

BAENID^. 


71 


On  the  left'bridge  there  are  four  inframarginal  scutes.  Of  these  the  second  is  the  smallest, 
the  first  and  the  fourth  the  largest.  All  the  plastral,  as  well  as  the  carapacial  scutes,  agree 
closely  with  those  of  Leidy's  type. 

A  portion  of  the  pelvis  is  preserved  (fig.  51).  So  far  as  can  be  determined,  it  agrees  well 
with  that  of  the  type  of  the  species.    Unfortunately,  the  upper  end  of  the  ilium  is  missing. 

Professor  Cope  figured  and  described  what  he  regarded  as  a  specimen  of  B.  arenosa  (Vert. 
Tert.  Form.  West,  p.  148,  plate  xvii,  figs.  I,  2).  The  specimen  is  in  the  American  Museum  and 
has  the  number  1 1 1 2.    The  present  writer  regards  it  as  belonging  to  B.  riparta. 

Professor  Cope  has  described  and  figured  also  a  portion  of  a  carapace  found  by  him  in  the 

Wasatch  beds  of  New  Mexico.  As  the  type  of  B.  arenosa 
was  discovered  in  the  lowermost  beds  of  the  Bridger,  it  is 
not  impossible  that  the  species  may  occur  in  the  Wasatch; 
but  the  identification  based  on  a  part  of  the  shell  is  not 
to  be  depended  upon. 

However,  the  American  Museum  expedition  of  1906 
into  the  Wasatch  deposits  of  Wyoming  secured  a  specimen 
oi Baena  which  is  referred  to  this  species.  This  was  found 
near  Knight's  Station,  not  far  from  Evanston.  The  level 
was  about  200  feet  above  Bear  River.  The  catalog  number 
of  the  specimen  is  6041.  About  one-third  of  the  carapace 
in  front  has  been  eroded  away,  but  otherwise  the  shell  is 
in  fair  condition.  The  length  of  the  carapace  was  origi- 
nally about  240  mm.  The  width  at  the  middle  of  the  length 
is  222  mm.,  and  this  width  is  fully  maintained  to  opposite  the  ends  of  the  femoro-anal  sulci. 
So  far  as  can  be  determined  this  specimen  differs  from  most  Bridger  specimens  in  the  greater 
smoothness  of  the  areas  of  the  vertebral  scutes;  but  this  appears  to  have  been  nearly  the 
condition  of  Leidy's  type.  Cope's  specimen  obtained  in  the  Wasatch  of  New  Mexico  and 
referred  by  him  to  the  present  species  had  the  back  sculptured  as  in  most  Bridger  specimens. 
It  appears  best,  until  more  is  known  about  the  Wasatch  form,  to  identify  it  as  B.  arenosa. 


Fig.  51. — Ba'ena  arenosa.      X§. 
Pelvis  seen  from  below. 


Baena  sima  sp.  nov. 
Plate  13,  figs.  2,  3;    plate  14,  figs.  4-6;   plate  15;  teit-figs.  52-56. 

The  present  species  has  for  its  type  No.  5971  of  the  American  Museum  of  Natural  History. 

This  specimen  was  collected  by  that  museum's  expedition  of  1903  into  the  Bridger  beds.    The 

locality  is  on  Little  Dry  Creek,  south  of  Fort  Bridger,  and  the  level  is  that  designated  as  B.    The 

specimen  furnishes  nearly  the  whole  of  the  shell,  the  skull,  with  the  lower  jaw,  a  number  of 

vertebrae,  and  portions  of  the  limb  bones. 

The  bones  of  the  shell  are  so  thoroly  co-ossified  that  few  of  the  sutures  can  be  made 

out.    The  carapace  (fig.  52)  has  an  axial  length  of  360  mm,;  the  width  was  close  to  260  mm. 

It  was  apparently  rather  elevated.    There  is  no  depression  along  the  midline.    In  outline  the 

carapace  was  pointed  in  front  and  somewhat  contracted  behind. 
Posteriorly  there  is  in  the  border,  over  the  tail,  a  rather  deep 
excavation  72  mm.  wide.  The  posterior  peripherals  are  flared 
upward.  The  surface  of  the  carapace  is  very  uneven,  being 
everywhere  covered  with  coarse  pustular  elevations;  just  outside 
of  the  third  and  fourth  vertebral  scutes  there  are  some  longitu- 
dinal wrinklings.  About  25  mm.  outside  of  these  vertebrals  there 
are  seen  on  each  side  distinct  traces  of  a  lateral  carina.    The 

median  symmetrically  arranged  folds  and  grooves  seen  in  B.  arenosa  are  here  quite  indistinct. 
The  nuchal  scute  has  a  fore-and-aft  width  of  16  mm.  and  a  transverse  extent  of  about  40  mm. 

The  first  vertebral  is  51  mm.  long  and  80  mm.  wide;   but  there  appears  to  be  on  the  left  side 

a  small  supernumerary  costal  scute  cut  out  of  its  normal  area.    The  other  scutes  have  the  areas 

given  in  the  table. 

Outside  of  the  nuchal  scute  there  is,  on  each  side,  a  minute  triangular  marginal  scute. 

The  next  one,  the  second,  is  21  mm.  long  on  the  free  border  and  21  mm.  high.    The  third  is 


Vertebral. 

Length. 

Width. 

2 

76 

68 

3 

gi 

69 

4 

79 

82 

5 

58 

83 

72 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


38  mm.  long  and  15  mm.  high.  The  seventh,  lying  below  the  hinder  half  of  the  second  costal,  is 
56  mm.  long  and  it  rises  about  36  mm.  above  the  free  border  of  the  shell.  On  account  of  the 
obtuse  border  over  the  bridge  the  elevation  of  the  lateral  scutes  is  difficult  to  estimate. 

The  plastron  (fig.  53)  is  320  mm.  long.  The  anterior  lobe  is  92  mm.  long,  112  mm.  wide 
at  the  base,  and  80  mm.  wide  at  the  gulo-humeral  sulci.  The  bridge  has  a  width  of  138  mm.,  60 
per  cent,  of  the  length  of  that  part  of  the  plastron  behind  the  axillary  notches.  The  hinder  lobe 
is  92  mm.  long,  127  mm.  wide  at  the  base,  and  92  mm.  at  the  ends  of  the  femoro-anal  sulci. 
The  hinder  border  is  slightly  excavated. 

The  mesoplastra  are  solidly  co-ossified  with  the  contiguous  bones,  but  some  traces  are 
found  of  the  sutures.    The  bones  appear  to  have  been  about  15  mm.  wide  at  the  midline. 

The  forms  of  the  various  plastral  scutes  are  shown  in  the  figure.  The  course  of  the  median 
sulcus  is  very  tortuous  and  there  are  some  irregularities  in  the  others.  The  axillary  region  is 
damaged  on  both  sides,  but  appearances  indicate  that  there  were  3  left  inframarginals,  the 


Figs.  52  AND  53. — Ba'ena  sima.     Type.    xj.     Showing  the  form  of  carapace 
and  plastron  and  the  scute  areas. 

52.     Carapace.  53.    Plastron. 

pectoral  scute  apparently  having  extended  out  to  the  marginals.  There  is  a  large  inguinal 
inframarginal  and  another  in  front  of  it.  There  was  doubtless  an  axillary  scute,  but  the  bones 
are  missing  which  supported  it.     On  the  right  side  there  were  4  inframarginals. 

The  skull  of  this  species  (plate  13,  figs,  i,  2;  plate  14,  fig.  4)  is  remarkable  for  its  breadth 
and  shortness.  The  premaxillary  region  is  missing  and  likewise  the  condyle  of  the  basioc- 
cipital;  but  the  length  from  one  to  the  other  was  very  close  to  64  mm.  The  breadth  across  the 
quadrates  is  71  mm.  From  the  quadrates  the  outline  of  the  skull  contracts  rapidly  to  below 
the  front  of  the  orbits,  where  there  is  a  sudden  constriction.  From  this  the  outline  contracts 
slowly,  then  rounds  into  the  broad  snout.  The  upper  surface  is  convex.  All  the  bones  are 
solidly  co-ossified,  and  no  sutures  are  to  be  traced. 

The  temporal  fossx  are  rooft  over  extensively,  so  that  between  the  end  of  the  short 
supraoccipital  and  the  postero-lateral  angles  there  is  on  each  side  only  a  shallow  sinus.  The 
interorbital  space  is  26  mm.  wide.   The  orbits  have  their  greatest  diameter,  17  mm.  directed  per- 


BAENID^.  ']T, 

pendicularly,  while  the  horizontal  diameter  is  only  14  mm.  The  narial  opening  is  21  mm.  wide 
and  it  looks  strongly  upward  as  well  as  forward.  The  bones  roofing  it  are  6  mm.  thick.  The 
tympanic  region  is  damaged,  but  the  vertical  diameter  was  20  mm.  The  quadrate  is  deeply 
notcht  for  the  passage  of  the  stapedial  rod. 

At  their  narrowest  part  the  pterygoids  are  14  mm.  wide.  There  are  large  postpalatine 
foramina.  The  front  of  the  choanae  is  placed  17  mm.  behind  the  premaxillae.  The  cutting- 
edges  of  the  maxillae  converge  at  nearly  right  angles.  The  triturating  surface  is  7  mm.  wide. 
At  its  inner  border,  on  each  side  of  the  choanae,  arises  a  sharp  crest.  These  crests  converge  to 
the  front  of  the  choanae,  then  run  parallel  to  near  the  premaxillae,  thus  producing  a  deep 
groove  in  front  of  the  choanx. 

The  lower  jaw  (plate  14,  figs.  5,  6)  is  thick  and  heavy.  From  the  middle  of  a  line  joining 
the  front  borders  of  the  articulation  for  the  quadrates  to  the  tip  of  the  jaw  is  40  mm.  This  line 
prolonged  backward  even  with  the  extremities  of  the  rami  would  measure  about  52  mm.  while 
the  greatest  width  was  60  mm.  The  triturating  surfaces  are  concave  transversely,  and  are  7 
mm.  wide.  The  middle  of  each  ramus  is  9  mm.  thick  and  15  mm.  high.  The  tip  of  the  jaw  is 
turned  upward,  beak-like.     The  length  of  the  symphysis  on  the  lower  side  is  21  mm. 

The  upper  surface  of  the  skull  was  undoubtedly  covered  with  numerous  horny  scutes. 
These  are  shown,  as  far  as  determined,  in  plate  13,  fig.  i.  They  are  somewhat  irregular  in 
form  and  disposition,  but  there  is  no  difficulty  in  making  out  some  symmetry  in  their  arrange- 
ment. The  horny  covering  of  the  maxillae  appears  to  have  been  divided,  for  a  deep  sulcus  runs 
downward  from  the  front  of  the  orbit  to  the  cutting-edge. 


Figs.  54-56. — Bdena  sima.     No.  5907  A.  M.  N.  H. 
54.  Pelvis,  right  side.     Xj.  56.  Digit.     Xi-  SS-  D'stal  end  of  humerus.     Xi. 

Accompanying  the  shell  of  this  specimen  are  various  portions  of  the  internal  skeleton, 
mostly  fragmentary,  however.  The  left  humerus  is  represented  by  the  proximal  and  the  distal 
ends.  The  proximal  shows  a  width,  from  the  outside  of  the  ulnar  to  the  outside  of  the  radial 
process,  of  33  mm.,  a  single  millimeter  more  than  in  the  specimen  of  B.  arenosa,  No.  5973? 
above  described.  Nevertheless,  the  long  diameter  of  the  head  is  14.5  mm.;  that  of  No.  5973, 
13  mm.  The  ulnar  process  has  a  thickness  of  11  mm.;  that  of  No.  5973  a  thickness  of  9  mm. 
The  distal  end  of  this  bone  is  27  mm.  wide.  The  trochlea  has  a  narrow  rounded  ridge  for  the 
head  of  the  radius  and  a  broader  one  for  the  head  of  the  ulna,  the  two  being  separated  by  a 
groove.  Above  the  trochlea  is  a  deep  olecranon  depression.  The  prepubic  process  resembles 
that  represented  in  fig.  86,  but  it  is  thin  and  flat.  With  this  specimen  are  found  3  conical  dermal 
bones  whose  bases  were  buried  in  the  skin,  the  remainder  being  covered  with  horn.  Two  of 
these  are  symmetrical  and  may  have  been  placed  on  the  midline  of  the  upper  side  of  the  tail,  as 
in  Chelydra.  However,  they  are  not  comprest,  but  circular  in  section.  The  base  of  one  is  10 
mm.  in  diameter  and  the  height  is  the  same;  the  other  is  smaller.  The  third  is  unsymmetrical 
and  somewhat  flattened.  It  is  possible  that  on  the  tail  were  3  rows  of  dermal  bones  or  there 
may  have  been  dermal  bones  on  the  legs,  as  in  some  species  of  7"cj<u</o. 

No.  5965  may  be  regarded  as  the  paratype  of  the  present  species.  It  furnishes  only  the 
carapace  and  plastron.  It  was  secured  in  1903,  at  Grizzly  Buttes,  Wyoming.  The  carapace  is 
more  complete  than  that  of  the  type  and  has  furnisht  plate  15.    The  length  is  333  mm.  along 


74  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

the  midline.  The  height,  after  some  crushing,  is  still  132  mm.  The  scallops  of  the  hinder 
border  are  shallow.  The  surface  of  the  carapace  is  sculptured  as  in  the  type.  The  symmetrical 
ridges  and  grooves  found  in  B.  arcnosa  and  B.  riparia  are  here  obscure.  On  the  hinder  half  of 
the  carapace  there  are  a  few  irregular  longitudinal  folds  and  a  system  ot  anastomosing 
ridges  and  pustular  elevations.  The  outer  ends  of  the  costal  scute  areas,  the  marginal  areas, 
and  the  whole  anterior  half  of  the  carapace  are  much  smoother.  The  nuchal  scute  is  not 
divided.  On  each  of  the  bridges  there  were  four  inframarginal  scutes.  The  bridge  region  of 
fig.  53  has  been  completed  from  this  specimen. 

No.  5907  of  the  American  Museum  was  collected  in  1903  by  the  writer  at  Grizzly  Buttes, 
Wyoming.  It  may  be  regarded  as  a  second  paratype.  It  furnishes  the  shell,  fragments  of  the 
skull,  the  pelvis,  and  some  limb  bones.  The  shell  appears  not  to  have  been  distorted  by 
pressure.  The  plastron  has  exactly  the  length  of  that  of  the  type.  The  width  of  the  carapace 
is  290  mm.;  the  height  above  the  bottom  of  the  plastron,  150  mm.  On  the  right  bridge  there 
are  only  3  inframarginal  scutes,  and  the  pectoral  scute  joins  the  sixth  marginal.  On  the  carapace 
the  nuchal  scute  is  not  divided  longitudinally.  On  each  side,  as  in  the  other  specimens,  is  a 
small  marginal  followed  by  a  much  larger  one,  that  on  the  right  side  being  larger.  The  super- 
numerary costals  are  not  found  at  the  sides  of  the  first  vertebral. 

The  pelvis  is  represented  by  fig.  54.  The  shaft  of  the  ilium,  where  narrowest,  has  a  diam- 
eter of  10  mm.  The  expanded  head  is  34  mm.  high  and  33  mm.  wide,  while  in  Chisternon 
undatum  the  head  is  considerably  higher  than  wide.  The  pubis  is  thin,  4.5  mm.,  slightly 
convex  above,  concave  below.     The  pelvis  resembles  closely  that  of  the  type  of  B.  arenosa. 

Fig.  55  is  that  of  the  distal  end  of  the  humerus,  seen  from  above.  The  radius  is  a  terete 
bone  57  mm.  long.  Fig.  56  represents  one  of  the  digits.  The  right  femur  is  78  mm.  long  and  is  a 
stout  bone  with  a  minimum  diameter  of  8  mm.  The  plane  passing  thru  the  strongly  comprest 
head  falls  outside  the  tibial  border  of  the  distal  end  far  less  than  in  a  specimen  of  Trachemys 
elegans.  The  tibia  had  a  length  somewhat  exceeding  63  mm.,  and  the  least  diameter  of  the 
shaft  is  7  mm.    The  distal  end  of  the  fibula  has  a  width  of  13  mm. 

The  greater  portion  of  the  lower  jaw  is  present  and  it  is  of  the  same  heavy  construction  as 
that  of  the  type.  Fragments  of  the  roof  of  the  skull  show  that  the  bones  in  the  midline,  behind 
the  orbits,  were  7  mm.  thick. 

Baena  clara  sp.  nov. 
Plate  16,  figs.  I,  i;   text-figs.  57,  58. 

This  species  is  based  on  a  nearly  complete  shell  which  was  collected  by  the  American 
Museum  expedition  of  1893.  It  was  obtained  in  the  Bridget  beds  of  Wyoming  and  bears  the 
number  1675.  The  exact  level  and  locality  are  not  known.  Only  unimportant  portions  of  the 
front  of  the  carapace  are  wanting. 

The  extreme  length  of  the  carapace  (plate  16,  fig.  i)  is  362  mm.;  its  width  across  the  middle, 
where  it  is  widest,  is  300  mm.  The  shell  is  but  little  distorted  by  pressure.  It  is  elegantly  oval 
in  form,  with  the  edges  of  the  hinder  border  of  the  carapace  furnisht  with  shallow  scallops, 
and  with  a  deep  excavation  in  the  rear,  as  if  for  a  large  tail.  The  shell  is  flat  transversely  in  the 
region  occupied  by  the  vertebral  scutes.  There  is  no  carina,  except  along  the  fifth  vertebral 
scute.  Immediately  in  front  of  this,  for  a  short  distance,  there  is  a  narrow  median  ridge,  like 
that  seen  in  B.  arenosa.  Over  and  behind  the  posterior  legs  the  shell  is  flared  outward  and 
slightly  upward.  In  front  and  behind  the  bone  is  rather  thin;  but  anteriorly  it  soon  thickens, 
so  that  over  the  fore  legs  it  has  a  thickness  of  about  15  mm.  At  the  sides  the  margins  of  the 
shell  are  massive. 

The  carapace  is  smooth,  with  only  some  faint  indications  of  the  sculpturing  seen  in  B. 
arenosa. 

The  plastron  (plate  16,  fig.  2;  text-fig.  58)  has  a  length  of  333  mm.  in  the  midline.  It  was 
flat  as  far  out  as  the  bridges.  From  the  inner  ends  of  these  the  plastron  rises  upward  and 
outward  to  the  margins  of  the  carapace,  so  that  the  latter  stands  some  50  mm.  above  the  level 
of  the  plastron.     The  highest  part  of  the  shell  stood  above  the  plastron  about  150  mm. 

The  anterior  lobe  of  the  plastron  is  tongue-shaped,  rounded  in  front,  and  feebly  notcht. 
In  the  figures  it  appears  foreshortened,  having  been  prest  upward  during  fossilization.     Its 


BAENID^. 


75 


width  at  its  base  is  125  mm.;  its  length  in  the  middle  line  is  90  mm.  At  a  point  half-way 
between  the  tip  and  the  base  the  width  is  88  mm.  The  width  of  the  bridge  is  145  mm.  The 
hinder  lobe  of  the  plastron  is  broadly  tongue-shaped,  with  the  tip  truncated  and  broadly 
notcht.    At  its  base  this  lobe  is  125  mm.  wide;  and  in  the  midline  it  is  100  mm.  long. 

The  sutures  between  the  various  bones  of  the  shell  are  usually  very  obscure,  but  most  of 
them  are  determinable.  The  limits  of  the  neurals  (fig.  57)  are  somewhat  conjectural.  Those 
between  the  costals  and  the  peripherals  run  probably  close  to  the  sulcus  between  the  costal  and 
peripheral  bones.    The  most  anterior  peripherals,  however,  rise  above  this  sulcus. 

The  sutures  of  the  plastron  are  hard  to  trace.  Only  the  general  course  of  those  limiting  the 
entoplastron  and  the  epiplastra  is  discernible.  The  sutures  between  the  bones  of  the  plastron 
and  the  peripherals  lie  about  44  mm.,  mesiad  of  the  shell  margin.  At  a  point  about  40  mm. 
behind  the  axillary  notch  is  observed  the  suture  between  the  hyoplastron  and  the  mesoplastron. 
Its  course  is  inward  and  somewhat  backward  to  a  point  in  the  midline  about  66  mm.  behind  the 
line  joining  the  axillary  notches.  Another  distinct  suture  may  be  observed  about  38  mm.  in 
front  of  the  inguinal  notch  on  the  left  side.  It  can  be  traced  toward  the  midline,  where  it 
becomes  obscure.  This  suture  is  that  between  the  mesoplastron  and  the  hypoplastron.  Thus 
the  inner  ends  of  the  mesoplastron  are  about  24  mm.  wide. 


57- 


Figs.  57  and  58. — Baena  clara.     Type.      Xi- 
57.  Carapace.  58.  Plastron. 

At  a  point  in  the  midline  about  45  mm.  behind  a  line  joining  the  inguinal  notches  the 
sutures  between  the  hypoplastra  and  the  xiphiplastra  are  seen  running  nearly  directly  outward. 

The  impressions  defining  the  epidermal  scutes  are  usually  very  distinct.  The  sides  of  the 
vertebral  scutes  are  bracket-shaped.  The  lateral  boundaries  of  the  first  vertebral  run  nearly 
parallel  and  the  scute  is  nearly  as  wide  in  front  as  it  is  behind.  It  has  a  length  of  56  mm.,  a 
posterior  breadth  of  63  mm.,  and  an  anterior  breadth  of  about  58  mm.  The  lateral  sulcus 
on  the  left  side  is  deflected  somewhat  toward  the  right  side  as  it  passes  forward.  It  is  possible 
that  an  accessory  lateral  scute  is  cut  off  from  the  front  of  the  usual  first  lateral  scute  and  lies 
to  the  left  of  the  first  vertebral.    It  is  provisionally  represented  in  the  diagram  above. 


76  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

The  second  vertebral  scute  is  90  mm.  long  in  the  midline,  and  is  72  mm.  wide  across  its 
middle.  Similarly,  the  third  scute  is  87  mm.  long  and  72  mm.  wide;  the  fourth,  75  mm.  long, 
deeply  concave  behind,  and  75  mm.  wide.  The  fifth  scute  is  35  mm.  long  and  100  mm.  wide. 
Its  posterior  edge  comes  to  the  border  of  the  shell,  there  being  no  supracaudal. 

The  anterior  marginals  are  somewhat  damaged.  In  front  there  is  a  nuchal  scute  30  mm. 
from  side  to  side  and  16  mm.  fore  and  aft.  On  the  right  side  there  are  2  small  marginals, 
each  about  15  mm.  long.  On  the  left  side  there  is  I,  perhaps  2,  corresponding  marginals.  Then 
follows,  on  each  side,  a  marginal  about  44  mm.  long,  succeeded  by  several  others  of  about 
the  same  or  greater  length.  Further  behind  they  shorten  gradually,  and  the  last  one  is  very 
small.  The  first  long  marginal  has  a  height  of  20  mm.  at  its  middle;  the  majority  of  them 
have  a  height  of  about  38  mm.    Further  behind  the  height  is  less. 

The  sulcus  running  along  the  midline  of  the  plastron  pursues  a  very  irregular  course,  and 
the  same  is  true  of  some  of  the  others.  That  behind  the  gulars  runs  from  the  midline 
outward  and  backward  for  half  its  length,  thence  forward  and  outward.  That  defining  the 
intergulars  does  not,  at  the  midline,  quite  reach  the  one  behind  the  gulars.  The  pectorals  are 
about  87  mm.  wide  at  the  midline;  the  abdominals  about  35  mm. 

The  sulcus  between  the  femorals  and  the  anals  is  extremely  irregular.  The  right 
femoral  at  the  midline  is  62  mm.  wide,  the  left,  78  mm.  wide.  There  are  four  inframar- 
ginal  scutes.  The  first,  or  axillary,  is  58  mm.  long  and  40  mm.  wide;  the  second  has  the  form 
of  a  trapezium,  with  outer  and  hinder  borders  each  about  40  mm.;  the  third  is  four-sided, 
50  mm.  long,  60  mm.  wide.     The  inguinal  scute  is  pentagonal,  about  46  mm.  long  and  broad. 

A  second  specimen  belonging  apparently  to  this  species,  No.  5957  of  the  American  Museum, 
was  collected  in  the  Bridger  beds  in  1903.  It  has  the  first  vertebral  scute  symmetrical,  43  mm. 
wide  in  front,  65  mm.  wide  posteriorly.  There  is  on  each  side  of  it  a  triangular  super- 
numerary costal  scute. 

From  B.  arenosa  the  present  species  differs  in  displaying  with  considerable  distinctness 
the  sutures  between  the  various  bones.  In  no  specimens  oi  B.  arenosa  that  have  hitherto  been 
collected  have  the  sutures  of  the  carapace  been  observed.  It  is  unlikely  that  this  disappearance 
of  the  sutures  is  due  to  greater  age  of  the  specimens  of  B.  arenosa.  Furthermore,  the  cara- 
pace of  B.  arenosa  has  a  quite  elaborate  sculpturing  along  the  middle  of  the  back.  Of  this 
B.  clara  shows  only  the  merest  suggestions.  The  rear  of  B.  clara  is  scallopt,  but  the  cuts 
are  much  shallower  than  in  the  other  species.  The  vertebral  scutes  of  B.  clara  are  narrower 
than  those  of  B.  arenosa.  However,  the  most  striking  differences  between  B.  clara  and  the  two 
species  above  mentioned  are  found  in  the  shape  of  the  shell.  The  outline  of  B.  clara  is  oval. 
The  widest  part  is  across  the  middle  of  the  length  and  from  this  the  border  curves  gracefully 
toward  the  front  and  rear.  In  B.  arenosa  the  outline  is  somewhat  quadrate.  The  sides  are 
approximately  parallel  as  far  back  as  the  rear  of  the  plastron;  then  the  border  turns  abruptly 
toward  the  midline. 

Baena  riparia  sp.  nov. 
Plates  17,  i8;  plate  19,  figs.  1-3;  teit-figs.  59-66. 
Baena  arenosa,  CoPE,  Vert.  Tert.  Form.  West,  1884,  p.  148,  plate  xvii,  figs.  I,  2  (not  of  Leidy). 

Baena  riparia  has  as  its  type  a  fine  shell  and  skeleton,  a  prize  of  the  American  Museum 
expedition  of  1903  into  the  Bridger  deposits  of  southwestern  Wyoming.  It  was  found  at  the 
Grizzly  Buttes,  about  15  miles  southeast  of  Fort  Bridger.  The  beds  belong  to  those  designated 
as  B.   The  specimen  is  in  the  American  Museum  of  Natural  History  and  has  the  number  5977- 

The  carapace  (plate  17;  text-fig.  59)  of  this  specimen  is  slightly  crusht  on  the  left  side 
and  the  hindermost  peripherals  are  mostly  gone;  otherwise  the  shell  is  complete.  The  cara- 
pace is  especially  valuable  because  the  bones  are  not  co-ossified,  and  practically  all  the 
elements  may  be  determined.  It  has  an  axial  length  of  about  315  mm.,  a  slight  dislocation  of 
the  bones  of  the  rear  making  the  estimate  inexact.  The  width  is  260  mm.  From  the  middle 
of  the  length  the  width  decreases  gradually  to  the  somewhat  projecting  front.  The  rear  has  a 
wide  but  shallow  sinus  over  the  tail.  In  fig.  59  the  outline  of  the  rear  behind  the  eighth  periph- 
eral to  near  the  pygal  is  somewhat  conjectural,  but  must  be  close  to  the  real  condition. 
Along  the  middle  of  the  back  there  runs  a  distinct  channel  which  extends  out  beyond  the 
neural  bones.    Along  the  middle  of  this  there  is  seen  a  narrow  ridge,  on  each  side  of  which 


BAENID^. 


n 


is  a  groove.    From  a  point  a  little  behind  the  center  of  each  vertebral  scute  a  few  folds  radiate 

to  the  ends  and  angles  of  the  scutal  areas.     Outside  of  these  areas  the  surface  of  the  shell  is 

somewhat  uneven. 

The  anterior  neurals  are  widest  in  front,  very  narrow  behind.    The  three  or  four  posterior 

are  wider.    The  sutures  are  somewhat  irregular.    Only  7  neurals  can  be  determined.    The 

seventh  is  larger  than  the  others  and  corresponds  to  the  seventh 
and  eighth  costal  plates;  but  no  suture  can  be  seen  crossing  it. 

The  nuchal  bone  is  slightly  broader  than  long,  46  mm.  by  35 
mm.  The  pygal,  somewhat  damaged,  is  broader  than  long. 
The  peripherals  do  not  differ  greatly  in  height,  this  being  about 
27  mm.  There  were  apparently  12  of  these  bones  on  each  side. 
The  sulci  are  distinctly  imprest,  but  narrow.  The  nuchal 
scute  is  distinctly  divided  into  a  right  and  a  left.  At  each  side  of 
it  is  a  minute  triangular  first  marginal.    The  second  marginal  is 

33  mm.  long  on  the  free  border;  the  third,  39  mm.;  the  eighth,  38  mm.    The  dimensions  of 

the  vertebral  scutes  are  shown  in  the  table. 


Vertebral. 

Length. 

Width. 

44 

48 

7* 

S' 

73 

57 

68 

61 

5o± 

9o±     , 

Figs.  59  and  60. — Baena  riparia.     Type.     Xj. 

59.  Carapace,  showing  bones  and  scute  areas. 

60.  Plastron,    abj  abdominal  scute;    isn,  anal  scute;    ent^  entroplastroa;    epi,  epiplastron;   /fm,  femoral  scute;    g, 

gular  scute;    hum^  humeral  scute;    hyo,  hyoplastron;    hypo,   hypoplastron;     rn/m,    inframarginal    scutes; 
mei,  mesoplastron;  ptc,  pectoral  scute;  xiph,  liphiplastron. 

There  are  on  each  side  5  costal  scutes,  a  small  supernumerary  one  being  situated  on  each 
side  of  the  first  vertebral.  Whether  there  are  13  or  14  marginals  is  uncertain.  There  is  no 
supracaudal  scute  occupying  the  midline  over  the  tail. 

The  plastron  (plate  18;  text-fig.  60)  is  262  mm.  long  on  the  midline.  Its  width  is  close  to 
200  mm.  As  in  the  other  species  of  the  genus,  it  sends  upward  strong  axillary  and  inguinal 
buttresses.    The  former  rise  to  within  25  mm.  of  the  first  dorsal  vertebra.    They  are  joined 


78 


FOSSIL   TURTLES   OF   NORTH   AMERICA. 


by  the  ribs  of  the  vertebra  mentioned.  These  buttresses  extend  inward  from  the  sides  of  the 
shell,  forming  partitions  whose  inner  borders  are  distant  from  each  other  85  mm.  The  upper 
ends  of  the  inguinal  buttresses  rise  high  against  the  contiguous  borders  of  the  fifth  and  sixth 
costal  plates.  Between  the  axillary  and  the  inguinal  buttresses  of  each  side  there  is  a  deep 
sternal  chamber. 

The  anterior  lobe  is  70  mm.  long,  90  mm.  wide  at  the  base,  and  64  mm.  at  the  gulo-humeral 
sulci.  It  contracts  gradually  to  these  sulci,  then  sweeps  round  to  the  midline.  The  free 
border  is  obtuse  and  the  greater  part  of  the  lobe  is  10  mm.  thick.  The  entoplastron  is  long  and 
narrow,  its  length  being  45  mm.,  its  width  26  mm.  The  mesoplastra  fail  by  about  16  mm.  of 
reaching  the  midline.  Laterally  they  expand  to  a  width  of  64  mm.  The  bridges  are  1 16  mm. 
wide — 62  per  cent,  of  the  length  of  that  part  of  the  plastron  behind  the  axillary  notches. 

The  hinder  lobe  is  78  mm.  long,  1 14  mm.  wide  at  the  base,  and  80  mm.  at  the  femoro-anal 
sulci.  The  hinder  border  is  slightly  notcht.  The  free  borders  are  subacute.  At  the  inguinal 
notch  the  thickness  of  the  bone  is  18  mm.,  but  backward  it  thins  to  about  4  mm. 

The  intergulars  and  the  gulars  both  overlap  the  entoplastron.  On  each  bridge  there  are 
3  inframarginals,  an  axillary,  another  at  the  end  of  the  pectoro-abdominal  sulcus,  and  an 
inguinal.    The  pectoral  scute  comes  into  contact  with  the  sixth  marginal. 


Figs.  61-66. — Ba'ena  riparia.     Type. 


61.  Scapula. 

62.  Coracoid. 

63.  Humerus,  dorsal  view. 

64.  Humerus,  radial  border. 


65.  Femur,  dorsal  view 

66.  Right  hind  leg. 
66a.  Femur. 


The  skull  (plate  19,  figs,  i,  2)  of  this  specimen  is  considerably 
damaged.  Most  of  the  temporal  roof  is  missing,  as  are  the  squa- 
mosals and  the  premaxillae.  The  length  from  the  latter  bones  to 
the  occipital  condyle  was  close  to  57  mm.;  the  breadth  across  the 
quadrates  is  56  mm.  The  orbit  has  a  perpendicular  diameter  of  17 
mm.,  a  horizontal  diameter  of  15  mm.,  being  somewhat  larger  than  the  orbit  of  5.  sima,  which 
had  a  larger  skull.  The  interorbital  space  is  18.5  mm.  wide.  The  nasal  opening  is  17  mm. 
wide.  The  narrowest  part  of  the  pterygoids  is  13  mm.  wide.  On  the  inner  border  of  the  tritu- 
rating surface  of  each  maxilla  there  is  a  sharp  ridge,  as  in  B.  sima. 

The  lower  jaw  (plate  19,  fig.  3)  of  this  species  differs  greatly  from  that  of  5.  sima,  being  of 
much  lighter  construction  and  having  a  shorter  symphysis.  The  distance  from  the  tip  of  the  jaw 
to  the  middle  of  a  Hne  joining  the  front  of  one  articulatory  surface  for  the  quadrate  with  that 
of  the  other  is  40  mm.,  the  same  as  in  the  type  of  5.  sima.  The  distance  from  the  outside  of  one 
of  the  articulatory  surfaces  to  the  other  is  50  mm.,  much  less  than  in  B.  sima.  The  height 
of  the  middle  of  a  ramus  is  10  mm.,  the  thickness  7  mm.,  the  width  of  the  gutter-like  triturating 
surface  4  mrti.  The  length  of  the  lower  side  of  the  symphysis  is  15  mm.  Of  the  sutures  of  the 
upper  surface  of  the  skull  the  median,  running  between  the  nasals,  prefrontals,  frontals,  and 
parietals,  and  the  transverse  which  separates  the  parietals  from  the  frontals,  are  determinable. 


BAENID^.  79 

The  course  of  the  parieto-frontal  suture  is  different  from  that  of  Chisternon  hebraicum,  since 
mesially  it  is  placed  further  forward  and  runs  outward  and  somewhat  backward  to  the  orbit. 
The  upper  surface  of  the  skull  appears  to  have  been  covered  with  horny  scutes. 

All  of  the  cervical  vertebrae  are  present,  except  the  first.  The  whole  series  had  a  length  of 
close  to  100  mm.,  not  quite  one-third  the  length  of  the  carapace.  All  have  transverse  processes. 
All  have  a  sharp  crest  on  the  lower  side  of  the  centrum.  These  crests  are  so  deep  that  they 
would  have  interfered  greatly  with  any  considerable  flexure  of  the  neck  in  a  perpendicular 
plane.  The  second  centrum  is  flat  anteriorly,  very  concave  posteriorly.  The  third  is  moder- 
ately convex  in  front,  deeply  concave  behind.  The  fourth  has  the  anterior  end  concave  in  the 
center,  but  the  concavity  is  surrounded  by  a  broad  convex  wall.  The  hinder  end  is  shallowly 
concave.  The  fifth  is  rather  deeply  concave  in  front,  flat  behind.  From  the  outside  of  one  of 
the  postzygapophyses  to  that  of  the  other  of  the  vertebra  is  13  mm.  The  centrum  of  the  sixth 
cervical  is  concave  in  front.  The  form  of  the  hinder  end  can  not  be  observed.  The  front  of 
the  seventh  is  concave,  the  hinder  end  flat.  The  eighth  is  concave  in  front;  the  hinder  end  is 
quite  convex,  but  small.  The  first  dorsal  has  a  large  concavity  to  receive  the  convex  surface 
of  the  eighth  cervical.  This  concavity  looks  directly  forward,  as  in  the  Pleurodira,  not  down- 
ward as  in  the  Cryptodira.  This  is  another  indication  that  the  head  and  neck  were  not 
retracted  within  the  shell.  In  the  hindermost  of  the  cervicals  the  zygapophyses  stand  high 
above  the  centra.  Furthermore,  the  ends  of  the  centra,  especially  when  they  are  flat  or 
convex,  are  considerably  higher  than  wide.  Both  these  conditions  would  be  unfavorable  to 
the  flexure  of  the  neck  in  a  perpendicular  plane.  The  postzygapophyses  of  the  last  cervical 
and  the  prezygapophyses  of  the  first  dorsal  are  short,  not  long  and  curved  like  those  of  the 
Cryptodira.  On  the  other  hand,  the  lateral  motion  of  the  neck  could  hardly  have  been  so  free 
as  in  the  Pleurodira;  and  there  was  no  projecting  roof  of  the  carapace  under  which  the  head 
could  be  concealed.  We  must  conclude  that  these  turtles  could  protect  their  heads  hardly  more 
than  the  sea-turtles. 

The  ascending  portion  of  the  scapula  (fig.  61)  is  long  and  slender;  as  is  also  the  precoracoid 
process.  The  coracoids  (fig.  62)  are  somewhat  damaged;  but  it  is  evident  that  the  median  end 
was  not  greatly  expanded,  not  so  much  as  in  some  Emydidae.  The  humerus  (figs.  63,  64)  is 
67  mm.  long.  The  shaft  is  little  bent.  The  distance  from  the  outside  of  the  radial  process  to  the 
outside  of  the  ulnar  is  27  mm.  The  breadth  of  the  distal  end  is  21  mm.  The  ectepicondylar 
foramen  is  situated  9  mm.  above  the  condyle.  The  humerus  is  slightly  longer  in  propor- 
tion to  the  length  of  the  carapace  than  in  Graptemys,  but  not  so  long  as  in  Chelydra.  The 
ulnar  process  does  not  extend  so  far  above  the  head  as  in  Chelydra.  The  remainder  of  the 
fore  limb  is  missing. 

The  pelvis  is  badly  crusht,  but  there  appear  to  be  no  striking  differences  between  it  and  that 
of  Chisternon  hebraicum  (figs.  85,  86).  The  ossified  prepubic  process  is  long,  and  it  resembles 
that  of  the  species  just  mentioned.  The  femur  (figs.  65,  66)  is  68  mm.  long  and  moderately  bent. 
In  proportion  to  the  length  of  the  carapace  the  femur  is  shorter  than  that  of  Graptemys  and 
still  shorter  than  that  of  Chelydra.  The  tibia  and  the  fibula  (fig.  66)  are  each  53  mm.  long. 
The  tarsal  bones  and  some  of  the  metatarsals  are  preserved.  The  second  metatarsal  is  21.5 
mm.  long.    This  appears  to  indicate  a  rather  long  foot. 

The  tail  was  long.  Eleven  of  the  vertebrae  are  preserved,  having  a  length  of  143  mm.; 
and  there  were  evidently  several  more.  So  far  as  determinable,  they  were  convexo-concave.  All 
probably  bore  chevron  bones.  Some  of  the  anterior  caudals  have,  in  the  position  of  the  neural 
spine,  a  rounded  boss,  as  if  for  the  support  of  a  distinct  bone,  such  as  occurs  on  some  of  the 
caudals  o(  Chelydra. 

The  specimen  figured  and  described  by  Cope  (Vert.  Tert.  Form.  West.,  p.  148,  pi.  xvii, 
figs.  I,  2)  as  Baena  arenosa  is  now  in  the  American  Museum  of  Natural  History  and  has  the 
catalog  number  11 12.  Cope's  figures  are  one-fourth  the  size  of  nature  and  are  inverted.  His 
measurements  are  in  some  cases  erroneous.  The  carapace  is  320  mm.  long,  instead  of  450  mm. 
The  carapace  is  somewhat  crusht  and  its  transverse  diameter  was  nearer  260  mm.  than  240  mm. 
The  length  of  the  plastron  is  290  mm.  The  anterior  lobe  is  82  mm.  long;  the  posterior  lobe 
87  mm.  The  width  of  the  base  of  the  anterior  lobe  is  102  mm.;  that  of  the  base  of  the  posterior 
lobe,   116  mm.    The  width  of  the  anterior  at  the  gulo-humeral  sulci  is  71  mm.;  that  of  the 


8o 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


posterior  at  the  femoro-anal  sulci,  87  mm.  As  stated  by  Cope,  there  are  three  inframarginal 
scutes  on  each  bridge.  The  present  writer  regards  the  specimens  as  belonging  to  B.  rtparia. 
The  sutures  are  obliterated. 

Baena  emilise  sp.  nov. 
Plate  20,  figs.  I,  1;   text-figs.  67,  68. 

The  type  of  this  species  is  a  nearly  complete  shell,  No.  1925,  of  the  American  Museum  of 
Natural  History  and  was  collected  in  1894,  by  Mr.  O.  A.  Peterson,  in  the  middle  Uinta  of  Utah. 
Through  pressure  the  left  side  has  been  crusht  in  and  small  portions  there  are  missing;  the 
edges  of  some  of  the  posterior  right  peripherals  are  also  broken  off.  On  one  side  or  the  other 
all  parts  are  present.  The  elements  of  the  shell  are  not  co-ossified,  and  we  are  therefore  able 
to  determine  the  limits  of  nearly  all  the  bones  entering  into  its  composition. 

The  length  of  the  carapace,  measured  in  a  straight  line,  is  368  mm.  (plate  20,  fig.  i;  text- 
fig.  67).  Its  greatest  width,  taken  at  the  middle  of  the  length,  is  294  mm. — almost  exactly 
the  size  of  the  specimen  described  as  B.  clara  and  not  much  smaller  than  the  specimen  of  B. 
arenosa,  No.  1 1 15  of  the  American  Museum.  It  may  therefore  be  conveniently  compared 
with  them. 


67. 


.-A 


q 

f 

\ 


Figs.  67  and  68. — Baena  emiUte.     Type.     Xj.     Shows  bones  and  scute  areas. 
67.  Carapace.  68.  Plastron. 

The  form  is  much  like  that  of  5.  arenosa,  being  rather  wide  behind,  245  mm.  at  the  hinder 
end  of  the  plastron.  The  posterior  border  is  furnisht  with  5  or  6  scallops,  the  cuts  between 
which  are  of  a  depth  intermediate  between  those  oiB.  arenosa  and  B.  clara.  The  upper  midline 
is  slightly  channeled,  except  on  the  last  vertebral,  where  there  is  a  prominent  carina. 

The  plastron  (plate  20,  fig.  2;  text-fig.  68)  resembles  in  general  that  of  the  other  species, 
but  the  anterior  and  the  posterior  lobes  are  comparatively  narrow.  The  total  length  is  320  mm. 
The  anterior  lobe  has  a  length  of  80  mm.,  a  width  of  1 10  mm.  The  tip  is  evenly  rounded,  the 
lateral  border  first  convex,  then  further  back  concave;  so  that  its  width  at  the  middle  of  its 
length  is  only  8 1  mm.  The  posterior  lobe  has  a  length  of  83  mm.  and  a  width  of  122  mm.  at  the 
base.  Its  posterior  border  is  nearly  straight.  The  width  of  the  bridge  is  160  mm.  The  plastron 
comes  within  about  40  mm.  of  the  end  of  the  carapace. 

This  species  agrees  with  B.  clara  in  having  only  4  costal  scutes,  instead  of  5.  The  lateral 
margins  of  the  first  vertebral  are  parallel  until  they  meet  the  marginals.    Then  the  edge  of  the 


Vertebral. 

Length. 

Width. 

55 

68 

go 

63 

92 

75 

70 

78 

70 

98 

BAENID^.  81 

vertebral  runs  forward  and  inward  to  the  midline.  The  table  below  gives  the  dimensions  of 
the  vertebral  scutes.  These  are  narrower  than  they  are  in  B.  arenosa  of  the  same  size,  and 
the  third  is  longer  than  in  any  of  the  described  species.    There  are  5  small  marginal  scutes 

lying  in  front  of  the  first  vertebral.  Two  of  these,  quadrilateral 
in  form,  about  26  mm.  long  and  20  mm.  wide,  occupy  respectively 
the  right  and  left  thirds  of  the  front  border  of  that  vertebral.  A 
pentagonal  scute  25  mm.  from  side  to  side  occupies  the  middle 
third.  It  measures  15  mm.  fore  and  aft;  and  its  narrowed  front 
scarcely  reaches  the  margin  of  the  shell,  since  two  other  small 
scutes  come  in  front  of  it,  one  on  each  side.  No  sulcus  is  seen 
along  the  midline. 

The  lateral  marginals  of  B.  emilice  are  higher  than  they  are  in 
either  B.  arenosa  or  B.  clara.  The  upper  border  of  the  one  below  the  anterior  angle  of  the  third 
costal  scute  stands  about  50  mm.  above  the  lower  edge  of  the  shell.  In  the  specimen  of  B. 
arenosa,  No.  1 1 15,  larger  than  the  shell  being  described,  the  corresponding  marginal  hardly 
reaches  40  mm.  The  upper  borders  of  the  marginals  of  B.  emilice  appear  to  follow  closely 
the  sutures  between  the  peripheral  bones  and  the  costal  plates. 

There  appear  to  be  13  marginals  on  each  side,  including  the  minute  anterior  one. 

The  epidermal  sulci  of  the  carapace  are  deeply  imprest;  those  of  the  plastron  are  rather 
obscure.  The  intergulars  reach  about  two-thirds  the  distance  to  the  humero-gular  sulcus. 
There  is  a  row  of  5  inframarginals  on  each  side.  As  to  the  other  plastral  scutes,  it  is  not 
observed  that  they  are  especially  different  from  those  of  S.  arenosa. 

It  is  possible  to  trace  the  sutures  between  all  the  bones  of  the  shell,  except  those  surrounding 
a  few  of  the  anterior  neurals  and  some  of  the  posterior  peripherals;  but  even  these  may  be 
located  approximately. 

It  will  be  observed  that  the  nuchal  does  not  have  the  great  antero-posterior  extent  that  it 
does  in  the  recent  Pleurodira.  The  neurals  are  in  general  elongated  hexagonal,  with  the  broad 
end  forward.  The  first  and  second  measure  together  83  mm.,  and  the  front  one  is  probably 
a  little  the  shorter.  Of  their  width  one  can  not  be  certain.  The  third  is  55  mm.  long,  and 
apparently  30  mm.  wide;  the  fourth,  43  mm.  long,  27  mm.  wide;  the  fifth,  43  mm.  long,  31  mm. 
wide;  the  sixth,  35  mm.  long,  32  mm.  wide;  the  seventh,  30  mm.  long,  and  the  same  in  width; 
the  eighth,  30  mm.  long,  and  34  mm.  wide.  Behind  the  last  neural  comes  the  pygal,  30  mm. 
long  and  60  mm.  wide.  No  suprapygal  is  found  between  the  last  neural  and  the  pygal.  The 
eighth  costal  plate  occupies  the  whole  lateral  border  of  the  eighth  neural  and,  in  addition, 
the  postero-lateral  portion  of  the  seventh  neural. 

The  nuchal  bone  has  a  fore-and-aft  extent  of  37  mm.  Its  width  from  side  to  side  is  about 
50  mm.  in  front  and  about  85  mm.  behind. 

There  are  almost  certainly  12  peripherals  on  each  side.  The  most  anterior  sutures  are 
easily  distinguisht;  but,  for  various  reasons,  not  the  posterior  ones.  Over  the  bridges  the 
sutures  between  the  peripherals  are  continuous  with  the  sutures  between  the  costal  bones; 
posteriorly,  there  is  not  this  correspondence.  The  sutures  are  not  traceable,  but  there  is 
undoubtedly  one  between  each  two  epidermal  sulci. 

On  the  plastron  all  the  sutures  are  easily  distinguisht.  The  total  length  of  the  plastron  is 
320  mm.  The  epiplastra  meet  in  the  midline  by  a  suture  13  mm.  long;  the  length  of  each  bone 
is  42  mm.  The  entoplastron  resembles  that  of  B.  arenosa,  as  figured  by  Leidy  (Cont.  Ext. 
Fauna  W.  Terr.,  pi.  xv,  figs.  4,  5).  Its  length  is  40  mm.;  its  breadth  34  mm.  The  suture 
between  the  hyoplastra  is  96  mm.  long.  The  mesoplastra  meet  in  the  midline  for  a  space 
of  33  mm.  At  their  outer  ends  they  are  75  mm.  wide.  The  suture  between  the  hypoplastra 
is  87  mm.  long.  The  xiphiplastral  suture  is  50  mm.  long,  and  each,  measured  at  its  anterior 
end,  is  50  mm.  wide.  The  anterior  and  posterior  buttresses  of  the  plastron  are  like  those  of 
B.   arenosa. 

Theintergularsmeasureon  the  midline  18  mm.;  the  gulars,  9  mm.;  the  humerals,  51  mm.; 
the  pectorals,  84  mm.;  the  abdominals,  42  mm.;  the  femorals,  64  mm.;  the  anals,  54  mm. 
On  the  bridge  are  5  inframarginals. 

In  the  middle  line  above  there  are  some  longitudinal  ridges  and  grooves  and  some  irregular 
elevations,  which  are  rudiments  or  vestiges  of  an  ornamentation  similar  to  that  of  B.  arenosa. 


82  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

This  species  differs  from  B.  arenosa  in  the  form  of  the  anterior  vertebral  scute  and  in 
having  no  accessory  lateral  scute.  In  these  respects  it  agrees  with  B.  clara.  From  the  latter  it 
differs  in  having  the  shell  broader  behind,  a  wider  and  more  deeply  scallopt  postero-lateral 
border,  higher  lateral  marginal  scutes,  a  different  arrangement  of  the  most  anterior  marginal 
scutes,  and  narrower  plastral  lobes.  The  bridge  of  the  plastron  is  also  wider.  It  measures 
1 60  mm.,  while  that  of  the  type  o(  B.  clara  is  only  150  mm.  The  bridge  of/?,  arenosa.  No.  1115, 
a  larger  shell,  also  measures  only  150  mm.  On  the  under  side  of  the  postero-lateral  border  of 
the  shell,  at  the  fifth  scallop,  the  distance  from  the  line  where  the  soft  skin  of  the  animal  began 
to  the  outer  edge  of  the  shell  is  40  mm.;  in  B.  clara  this  space  is  only  33  mm. 

There  is  in  the  American  Museum's  collection  a  second  specimen  of  this  species  from  the 
same  level.  It  is  somewhat  smaller,  with  a  total  length  of  323  mm.,  and  is  less  perfect  than  the 
one  which  has  furnisht  the  above  description.  Nevertheless,  the  principal  characters  distin- 
guishing the  species  from  the  others  are  exhibited.  Altho  smaller,  the  sutures  have  almost 
wholly  disappeared,  so  that  it  furnishes  no  aid  in  tracing  these. 

In  the  collection  of  Princeton  University  there  is  a  somewhat  damaged  shell  which  is 
referred  to  this  species.  The  catalog  number  is  1 1263.  It  was  collected  by  Mr.  J.  B.  Hatcher, 
in  1895,  in  the  Uinta  Eocene,  at  Kennedy's  Hole,  Utah.  The  beds  contained  remains  of 
Dolichorhinus  cornutus. 

Genus  EUBAENA  nov. 

Skull  resembling  that  of  Ba'ena,  but  with  the  temporal  region  less  extensively  rooft  over, 
the  squamosals  not  coming  into  contact  with  the  parietals.  Jugals  excluded  from  the  rims  of 
the  orbits.  Triturating  surfaces  of  the  maxillae  transversely  broad  and  concave.  Choanae 
opening  between  the  orbits,  and  at  nearly  one-third  the  distance  from  the  snout  to  the  occipital 
condyle.    Shell  unknown. 

Type  :  Euba'ena  cephalica  Hay. 

Eubaena  cephalica  Hay. 

Plate  19,  fig.  4;    plate  2t,  figs.  I,  2. 

Ba'ena  cephalica,  Hay,  Amer.  Jour.  Sci.  (4),  xvni,  1904,  p.  263,  plate  xii,  figs.  1-3. 

The  name  Euba'ena  cephalica  is  given  to  a  fine  skull  which  is  in  Yale  University  Museum. 
This  skull,  which  lacks  only  the  lower  jaw,  was  collected  in  the  Laramie  deposits  of  Converse 
County,  Wyoming,  by  Professor  J.  B.  Hatcher,  then  employed  by  Professor  O.  C.  Marsh.  The 
specimen  bears  Professor  Marsh's  receipt  number  21 10. 

In  general  form  the  skull  is  broad  behind,  rather  flat  above,  and  with  pointed  snout.  The 
length  from  the  snout  to  the  occipital  condyle  is  67  mm.;  to  the  end  of  the  supraoccipital 
spine,  74  mm.  The  greatest  breadth,  just  in  front  of  the  tympanic  chamber,  is  65  mm.  From 
these  chambers  the  width  diminishes  to  the  snout.  The  flat  upper  surface  of  the  skull  descends 
each  way  to  the  perpendicular  sides.  The  sides  of  the  face  about  the  orbits  look  upward  and 
outward,  as  well  as  forward.  The  tympanic  opening  is  nearly  circular,  19  mm.  in  its  perpen- 
dicular, 15  mm.  in  its  horizontal  axis.  The  orbit  is  circular  and  small,  its  diameter  being  14mm. 
The  interorbital  space  is  25  mm.  wide.  The  nasal  opening,  as  seen  from  in  front,  is  somewhat 
heart-shaped,  and  is  directed  above  and  forward.  From  the  orbit  to  the  tympanic  opening  is 
24  mm. ;  from  the  nares  to  the  orbit  is  10  mm. 

The  temporal  region  is  rooft  over,  but  not  so  extensively  as  in  species  oi Ba'ena  from  the 
Bridger  beds.  On  each  side  of  the  supraoccipital  this  roof  is  excavated  as  far  as  a  line  joining 
the  anterior  borders  of  the  tympanic  chambers.  From  the  orbit  to  the  bottom  of  the  excava- 
tion is  22  mm.  The  hinder  end  of  the  postfrontal  is  interposed  between  the  parietal  and  the 
squamosal. 

In  general,  the  sutures  of  the  skull  are  very  distinct,  but  no  trace  has  been  found  of  those 
between  the  frontals  and  the  parietals.  There  are  distinct  nasals,  and  these  and  the  prefrontals 
resemble  closely  the  same  bones  in  the  Bridger  species  of  Baenidae.  The  prefrontal  of  each 
side  joins  the  postfrontal,  so  that  the  area  of  the  frontal  is  excluded  from  the  border  of  the  orbit. 
The  sagittal  suture  extends  from  the  prefrontals  to  the  supraoccipital  spine,  a  distance  of 


BAENID^.  83 

42  mm.  The  postfrontal  is  large,  having  a  length  of  32  mm.,  being  in  contact  by  its  lower 
border  with  the  maxilla,  the  jugal,  and  the  quadratojugal;  and  by  its  posterior  border  with 
the  squamosal. 

The  jugal  is  small,  being  only  8  mm.  in  length  and  15  mm.  in  heigth.  The  squamosal  forms 
the  hinder  border  of  the  tympanic  opening.  Superiorly  it  has  a  thin  crest,  a  relic  of  the  former 
backward  extension  of  the  temporal  roof.  The  tympanic  chamber  extends  backward  into  this 
bone.  The  lower  border  of  the  zygomatic  bar  is  considerably  excavated.  Seen  from  the  side  the 
maxilla  is  convex  on  its  lower  border.  From  this  border  the  bone  rises  11  mm.  to  the  orbit. 
The  premaxillje  are  distinct  from  the  maxillae  and  from  each  other.  At  the  symphysis  they  are 
only  3  mm.  high,  but  at  the  union  with  the  maxillae,  10  mm.  high.  As  in  the  Bridger  species 
of  Ba'ena  there  are  distinct  lacrimal  bones.  The  lower  border  of  each  comes  into  contact 
with  the  vomer.    The  jugals  are  excluded  from  the  rims  of  the  orbits  (Plate  19,  fig.  4). 

As  seen  from  below,  the  maxilla  has  a  broad  masticatory  surface,  its  width  being  14  mm. 
from  its  inner  border  to  the  cutting-edge.  The  inner  border  of  this  surface  is  furnisht  by  the 
palatine  bone.  The  latter  forms  the  whole  of  the  outer  border  of  the  choana.  The  masticatory 
surface  does  not  extend  forward  on  the  premaxilla.  In  front  of  the  choanae  there  is  a  deep 
groove,  which  in  front  expands  on  the  lower  surface  of  the  premaxillae.  There  are  postpalatine 
foramina  (Plate  21,  fig.  2). 

The  pterygoids  come  into  short  contact  with  the  maxillae.  They  have  distinct  ectoptery- 
goid  processes.  Where  the  hinder  part  of  the  palate  is  constricted  it  is  18  mm.  wide.  The 
pterygoids  extend  backward  to  the  hinder  border  of  the  pedicel  of  the  quadrates,  thus  sepa- 
rating the  latter  widely  from  the  basioccipital  and  basisphenoid.  There  is  a  considerable 
groove  between  the  quadrate  on  each  side  and  the  median  bones  of  the  skull.  The  pterygoids 
join  in  the  midline  for  a  considerable  distance  in  front  of  the  basisphenoid.  There  is  on  each 
side  of  the  latter  bone,  about  the  middle  of  its  length,  a  venous  foramen. 

The  pedicels  of  the  quadrates  are  short.  The  surface  for  articulation  with  the  mandible 
is  deeply  concave  from  side  to  side,  nearly  plane  from  front  to  back. 

A  pair  of  epidermal  scutes  appears  to  have  occupied  the  space  between  the  anterior 
halves  of  the  orbits.  Behind  each  of  these  and  bounding  the  hinder  half  of  the  orbit  was  a 
smaller  scute.  A  very  large  scute,  or  more  probably  a  pair  of  them,  occupied  the  area  of  the 
frontal  bones  and  overlapt  behind  this  on  the  parietals.  The  hinder  half  of  this  scute,  or 
these  scutes,  if  two,  was  separated  by  two  median  scutes.  The  more  anterior  of  these  last  was 
circular;  the  more  posterior  was  broadened  backward  and  lay  on  the  whole  or  part  of  the 
supraoccipital  processes  of  the  parietals. 

Eubaena  latifrons  sp.  nov. 
Figs.  69,  70. 

The  specimen  on  which  the  present  species  is  based  was  found  by  Mr.  Barnum  Brown,  of 
the  American  Museum  of  Natural  History,  in  Laramie  deposits,  on  Seven  Mile  Creek,  Wyom- 
ing, about  40  miles  northwest  of  Edgemont,  South  Dakota.  It  has  the  catalog  number  6139. 
The  specimen  consists  of  the  skull,  without  the  lower  jaw.  This  skull  is  crusht  downward 
somewhat,  and  the  right  maxilla  is  forced  inward  partly  over  the  triturating  surface  of  that 
side.  The  left  maxilla  is  missing.  A  part  of  the  temporal  roof  is  broken  away  and  most  of 
the  supraoccipital  spine  is  gone. 

It  is  not  impossible  that  the  shell  of  this  species  has  already  been  described  as  one  of  the 
Laramie  species  of  Ba'ena;  but  this  can  not  be  determined  until  the  skull  and  the  shell  have 
been  found  together.  The  skull  resembles  that  of  £.  cephalica;  but  a  number  of  differences 
exist,  which  will  be  mentioned  as  the  description  proceeds. 

How  far  the  premaxillx  extended  beyond  the  front  of  the  nasal  bones  can  not  be  deter- 
mined exactly;  but  the  distance  appears  to  have  been  less  than  in  E.  cephalica.  It  may  be 
assumed  to  have  been  about  5  mm.  The  length  of  the  skull,  from  the  front  of  the  nasals  to  the 
occipital  condyle,  is  72  mm.  The  width  from  one  quadratojugal  to  the  other  is  73  mm. 
Evidently  the  orbits  looked  upward  less  than  in  E.  cephalica,  for  the  width  of  the  interorbital 
space  is  32  mm.;  in  E.  cephalica,  only  25  mm.  The  horizontal  diameter  of  the  orbit  is  17  mm., 
being  thus  more  than  in  the  species  with  which  it  is  compared.    The  tympanic  chamber,  too, 


84 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


is  larger  than  that  of  the  other  species,  the  horizontal  diameter  being  24  mm.  The  perpen- 
dicular diameter  is  now  only  16  mm.,  but  this  is  due,  no  doubt,  to  crushing.  From  the  orbit  to 
the  tympanic  cavity  is  22  mm. 

The  roofing  of  the  temporal  region  resembles  that  of  E.  cephalica.  Few  of  the  sutures  of 
the  upper  side  of  the  skull  can  be  traced  with  certainty;  but  it  is  evident  that  the  parietal 
union  with  the  squamosal  had  been  severed  by  the  excavation  in  the  hinder  border  of  the  roof. 
There  are  reasons  for  believing  that  the  parietals  were  each  15  mm.  wide  posteriorly.  If  the 
prefronto-nasal  suture  is  where  it  seems  to  be,  the  nasals  were  unusually  large,  running  along 
the  midline  8  mm.  The  parieto-frontal  and  the  fronto-prefrontal  sutures  can  not  be  deter- 
mined with  certainty.  The  nasal  opening  has  now  a  width  of  23  mm.  One  premaxilla  is 
present  and  has  the  height  and  the  width  each  9  mm.  The  maxilla,  below  the  orbit,  is  1 1  mm. 
wide,  being  thus  narrower  than  that  of  £.  cephalica. 

The  upper  surface  of  the  skull  is  rough  with  narrow  ridges,  separated  by  sharp  furrows. 
This  interferes  with  the  tracing  of  the  sutures;  for  the  latter  do  not  appear  to  be  really  absent. 
Occasional  narrow  grooves  indicate  that  the  skull  was  covered  with  horny  plates;  but  these 
can  not  be  mapt. 


Figs.  69  AND  70. — Euba'ena  latifrons.     Skull  of  type.     Xf. 
69.  Skull  seen  from  above.  70.  Skull  seen  from  below,    pmx,  premaxilla;  ro,  vomer. 

The  base  of  the  skull  and  the  roof  of  the  mouth  resemble  in  general  the  same  regions  of 
£.  cephalica.  At  the  pterygoid  constriction  the  width  is  only  16  mm.  The  postpalatine 
foramina  are  placed  24  mm.  apart;  whereas,  in  E.  cephalica  they  are  only  18  mm.  apart.  The 
maxillary  triturating  surfaces  appear  not  to  have  been  so  wide  as  those  of  E.  cephalica.  As  in 
the  latter  species,  they  are  bounded  on  the  inner  margin  by  a  rough  ridge. 

Genus  CHISTERNON   Leidy. 

Related  closely  to  Baena,  but  having  2  bones,  an  anterior  and  a  posterior,  occupying  the 
region  of  the  nuchal  of  Baena.  Normally  2  scutes  occupying  the  area  corresponding  to  the  first 
vertebral  oi Baena.     No  supramarginals.    Maxilla  with  a  nearly  plane  triturating  surface. 

Type,  Baena  undata  Leidy. 

The  genus  was  based  by  Dr.  Leidy  on  the  presence  of  the  mesoplastra,  but  these  were  after- 
wards found  to  be  present  in  Baena  arenosa  also.  The  existence  of  the  two  bones  in  the  region 
of  the  nuchal,  with  the  absence  of  supramarginals,  will  characterize  the  genus. 

Two  specimens  of  C.  undatum  and  one  belonging  to  Cope's  Baena  hebraica  in  the  American 
Museum  of  Natural  History  show  unmistakably  the  two  bones  mentioned  as  occurring  in  the 
region  of  the  anterior  neural. 

Remarks  on  the  significance  of  the  preneural  and  the  supernumerary  scutes  will  be  found 
on  page  ^y. 


BAENID^. 


85 


Chisternon  undatum   Leidy. 
Plate  22;   text-figs.  71-75. 

Baena  undata,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1871,  p.  228;  U.  S.  Geol.  Surv.  Montana,  etc.,  1871 
(1872),  p.  369. — Cope,  6th  Ann.  Report  U.  S.  Geol.  Surv.  Terrs.,  1872  (1873),  p.  622;  Vert.  Tert. 
Form.  West,  1884,  p.  147,  plate  xix,  Hgs.  3-5. — OsnoRN,  Scott,  and  Spier,  Contrib.  Mus.  Geol.  and 
Arch.  Princeton  Univ.,  No.  i,  1878,  p.  96. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  438. 

Chisternon  undatum,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1872,  p.  162;  Contrib.  Ext.  Fauna  West.  Terrs. 
1873.  PP-  169,  341,  plate  xiv,  figs,  i,  2. 

The  type  of  Leidy's  Chisternon  undatum  is  in  the  collection  of  the  Academy  of  Natural 
Sciences  at  Philadelphia.  The  specimen  is  said  to  have  been  collected  in  a  range  of  buttes  a  few 
miles  from  Fort  Bridger.  This  range  is  probably  Grizzly  Buttes  and  the  level  is  B.  The  shell 
belonged  to  a  turtle  whose  carapace  had  a  length  of  about  485  mm.  The  front  and  the  rear  of 
the  shell  are  missing,  so  that  Leidy  could  not  know  the  structure  of  the  bones  and  scutes  of  the 
front  of  the  carapace.  As  stated  by  that  author,  the  shell  is  rather  high  and  archt,  its  upper 
surface  standing  above  the  bottom  of  the  plastron  about  7.5  inches,  equal  to  190  mm.  The 
sutures  may  be  traced  by  means  of  the  band  of  striations  that  crost  them, and  Leidy  wasenabled 
to  map  correctly  the  bones  of  the  plastron.  The  mesoplastra  come  to  a  point  at  the  midline. 
The  costo-marginal  sulci  over  the  bridges  run  about  50  mm.  above  the  borders  of  the  shell. 


Figs.  71  and  J2.  — Chisternon  undatum.     Carapace  and  plastron. 


71.  Plastron  of  No.  3932  A.  M.  N.  H.    X  J.    Anterior  lobe  missing. 

72.  Carapace  of  No.  5959  A.  M.  N.  H.    X  \.    Areas  of  some  bones  not  mapt. 

Many  characters  given  by  Cope  as  distinguishing  this  species  from  C.  hebrauum  are  not 
conclusive.  There  is  no  appreciable  difference  in  the  sizes  of  the  anterior  lobes;  nor  do  the 
intergular  and  gular  scutes  of  C.  undatum  always  start  from  a  common  point.  So  far  as  the 
writer  has  observed,  the  marginal  scutes  of  C.  hehraicum  rise  considerably  higher  above  the 
margins  of  the  shell  over  the  bridges  than  they  do  in  C.  undatum.  As  will  be  shown  below, 
there  are  important  differences  in  the  skulls. 

In  the  American  Museum  there  are  4  large  shells  which  are  regarded  as  belongmg  to  this 
species.  In  none  of  these  are  the  boundaries  of  all  the  bones  to  be  made  out,  altho  in  some  ot 
them  many  sutures  may  be  traced. 

No.  3932  (plate  22;  text-fig.  71)  was  collected  in  1893  in  the  Bridger  beds  of  Wyoming,  but 
the  exact  locality  and  level  are  unknown.    The  length  along  the  midline  is  433  mm.;    the 


86 


FOSSIL   TURTLES    OF   NORTH   AMERICA. 


greatest  width,  387  mm.  The  outlines  of  many  of  the  neural  bones  are  determinable.  On  the 
front  of  the  carapace,  however,  the  indications  are  obscure.  The  vertebral  scutes  are  a  little 
longer  than  wide.  The  scutes  on  the  front  of  the  carapace  are  unsymmetrical.  On  the  left 
side  there  is  a  supernumerary  costal,  but  not  on  the  right  side.  The  anterior  vertebral  is  not 
transversely  divided  as  it  is  in  the  other  specimens.  Over  the  bridges  the  marginal  scutes  are 
not  more  than  45  mm.  high.  The  anterior  lobe  of  the  plastron  is  missing.  On  the  left  bridge 
there  are  only  three  inframarginal  scutes. 

No.  5974  was  collected  in  1903  near  the  mouth  of  Cottonwood  Creek,  in  the  level  called  B^. 
It  has  a  length  of  490  mm.  along  the  midline,  and  a  maximum  width  of  425  mm.  The  rear  of 
the  carapace  is  scallopt.  Most  of  the  sutures  are  indistinct,  but  the  small  nuchal  and  the 
large  preneural  are  plainly  separated.  The  former  is  38  mm.  long  and  46  mm.  wide;  the  latter, 
45  mm.  long  and  72  mm.  wide.  The  first  vertebral  scute  is  transversely  divided,  so  that  there 
are  present  really  6  vertebrals.  On  each  side  of  the  two  anterior  ones  is  a  supernumerary  costal, 
and  an  extra  scute  has  been  cut  off  from  the  first  vertebral  and  the  right  supernumerary  costal. 
The  marginals  over  the  bridges  appear  not  to  run  more  than  50  mm.  above  the  borders  of  the 
shell.  The  plastron  is  440  mm.  long.  The  entoplastron  has  a  length  of  80  mm.  and  a  width 
of  about  45  mm.  The  mesoplastral  sutures  are  not  wholly  distinct,  but  these  bones  appear 
to  have  come  to  a  point  at  the  midline.  The  anterior  lobe  is  120  mm.  long;  150  mm.  wide  at 
the  base;  93  mm.  wide  at  the  gulo-humeral  sulci.  The  bridge  is  205  mm.  wide.  The  hinder 
lobe  has  a  length  of  125  mm.;  a  width  of  155  mm.  at  the  base,  122  mm.  at  the  femoro-anal 
sulci.  On  each  bridge  are  4  inframarginal  scutes.  The  gulars  meet  each  other  for  a  dis- 
tance of  13  mm.  at  the  midline. 


73.  ^^  --^  74. 

Figs.  73-75. — Chisternon  undatum.     Skull  of  No.  5962  A.  M.  N.  H.      Xj. 
73.  Skull  seen  from  above.  74.  Skull  seen  from  below.  75.  Right  half  and  tip  of  lower  jaw. 

No.  5959  (fig.  72)  was  obtained  at  Grizzly  Buttes,  Wyoming,  in  1903.  The  axial  length  of 
the  carapace  is  455  mm.;  its  width,  400  mm.  As  in  No.  3932,  there  is  a  broad  depression  along 
the  midline  of  the  carapace.  There  is  a  distinct  nuchal  bone,  followed  by  a  larger  preneural. 
There  are  6  vertebral  scutes,  whose  dimensions  are  given  in  the  accompanying  table. 

There  is  a  small  supernumerary  costal  scute  on  each  side  of 
the  first  vertebral  scute  and  another  on  each  side  of  the  second 
(fig.  72).  The  border  of  the  shell  over  the  right  bridge  is  crusht, 
but  the  costo-marginal  sulci  appear  to  have  run  not  more  than 
60  mm.  above  the  border  of  the  shell.  The  entoplastron  is  80 
mm.  long  and  about  48  mm.  wide.  On  the  right  bridge  are  five 
inframarginals.    The  left  bridge  is  missing. 

No.  5962  was  collected  at  Grizzly  Buttes,  in  1903.  It  was 
lying  close  to  No.  5961,  a  specimen  of  C.  hebratcum.  The  cara- 
pace is  much  crusht  laterally  and  diagonally.  The  specimen  is 
valuable  because  it  furnishes  the  skull.  The  carapace  was  at  least  460  mm.  long.  So  far  as 
can  be  determined,  the  costo-marginal  sulci  pursued  their  courses  above  the  bridges  at  a  moder- 
ate height.  There  are  6  vertebral  scutes  and  a  pair  of  supernumerary  costals  in  front.  There 
are  traces  of  the  suture  between  the  nuchal  and  the  preneural. 

Most  of  the  dimensions  of  the  skull  (figs.  73,  74)  are  presented  on  page  89.    It  differs  from 
that  of  C  hebraicum  especially  in  the  broader  triturating  surfaces  of  the  maxillae  and  the  broader 


Vertebral. 

Length. 

Width. 

3S 

36 

44 

92 

95 

95 

105 

97 

105 

96 

6 

69 

105 

BAENID^. 


87 


pedicels  of  the  quadrates.  There  appears  to  have  been  only  a  rudimentary  ridge  on  the 
triturating  surface.  The  sutures  between  most  of  the  bones  may  be  traced,  but  those  separating 
the  frontals  from  the  parietals  have  not  been  observed.  Nasals  were  quite  certainly  present,  but 
they  are  broken  away.  The  lower  jaw  is  present  (fig.  75).  The  triturating  surface  is  trans- 
versely concave  and  9  mm.  wide.  The  tip  of  the  jaw  is  damaged  so  that  the  length  of  the 
symphysis  can  not  be  exactly  determined;  but  it  was  not  far  from  15  mm. 


Chisternon  hebraicum  Cope. 
Plate  21,  figs.  3,  4;    plate  23,  fig.  1;    text-figs.  76-87. 

Baena  hebraica,  CoPE,  Palseont.  Bull.  No.  I,  1872,  p.  463;  Proc.  Amer.  Philos.  Soc,  xii,  187^,  p.  463; 
6th  Ann.  Report,  U.  S.  Gaol.  Surv.  Terrs.,  1872  (1873),  p.  62;  Vert.  Tert.  Form.  West,  1884,  p.  146, 
plate  xix,  figs.  1,  2. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  438. 

Baena  undata.  Hay,  Bull.  Amer.  Mas.  Nat.  Hist.,  xxi,  1905,  p.  138,  figs.  1-3. 

Professor  Cope's  type  of  the  present  species  consists  of  about  two-thirds  of  the  anterior 
portion  of  the  carapace  and  the  plastron.  It  was  obtained  by  him  in  the  Bridger  Badlands 
along  Cottonwood  Creek,  Wyoming,  and  hence  in  the  level  known  as  B.  This  type  is  now  in  the 
U.  S.  National  Museum  at  Washington.     It  appears  to  be  necessary  to  correct  some  of  Cope's 

measurements.  The  transverse  axial  width 
is  given  by  him  as  500  mm.,  but  it  is  only 
420  mm.  Accordingly,  Cope's  figures  are 
just  one-third  the  size  of  nature.  Cope's 
estimate  of  the  length  was  also  500  mm., 
but  the  writer  would  make  it  only  about  425 
mm.  In  either  case  the  shell  is  about  as 
broad  as  long.  The  length  of  the  anterior 
lobe  of  the  plastron,  to  a  line  joining  the 
bottoms  of  the  axillary  notches,  is  125  mm. 
Its  width  is  147  mm.  The  bridges  are  162 
mm.  wide.  The  hinder  lobe  has  a  basal 
width  of  160  mm. 

As  shown  by  Cope's  figures,  the  nuchal 
and  the  anterior  marginal  scutes  have  small 
extent  at  right  angles  with  the  free  border, 
and  the  firstvertebral  is  transverselydivided 
so  as  to  make  6  vertebrals  in  all.  The  margi- 
nals over  the  bridges  are  higher  than  long, 
and  the  corresponding  costal  scutes  become 
thereby  about  as  high  as  long.    There  is 
likewise  a  supernumerary  costal  scute  on 
each  side  of  the  first  vertebral. 
The  shoulder-girdle  is  present,  but  has  not  been  wholly  freed   from  the  matrix.    The 
scapula  is  at  least  90  mm.  long  from  the  glenoid  fossa  to  the  upper  end.    At  its  base  the  cora- 
coid  has  a  diameter  of  7  mm.;  at  a  distance  of  65  mm.  from  the  glenoid  fossa  the  diameter  is 
65  mm. 

No.  5961  of  the  American  Museum  is  referred  to  this  species.  It  was  collected  in  1903  by 
Mr.  L.  S.  Quackenbush,  a  member  of  the  museum's  party.  The  locality  is  Grizzly  Buttes, 
not  far  from  the  locality  where  Cope's  type  was  collected.  It  was  found  lying  in  close  prox- 
imity with  the  specimen  numbered  5962  and  referred  to  Leidy's  Chisternon  undaium.  Both 
specimens  furnisht  good  skulls  and  other  skeletal  parts.  Figure  76  represents  the  carapace 
of  No.  5961 ;  fig.  yy,  the  plastron.  The  shell,  especially  in  the  region  of  the  distal  ends  of  the 
costals,  is  thin  and  fragile  and  some  parts  were  lost.  The  right  half  of  the  nuchal  is  gone,  the 
rear  of  the  carapace  is  missing. 

The  axial  length  of  the  carapace  was  close  to  474  mm. ;  the  greatest  width  435  mm.  It  was 
moderately  convex.  The  surface  is  nearly  smooth.  Along  the  areas  of  the  vertebral  scutes 
are  some  traces  of  the  sculpture  so  conspicuous  in  the  case  of  species  oi  Baena.    Across  some  of 


Fig.  76. 


'Chisternon  hebraicum.     Portion  of  carapace. 
Xj.     No.  5961  A.  M.N.  H. 

c.  p.  I,  front  costal  plate;   c.  s,  i,  first  costal  scute;   n.  i,  n.  2, 
neural  bones;   preriy  preneural. 


88 


FOSSIL  TURTLES   OF    NORTH   AMERICA. 


Neurals. 

Vertebrals. 

No. 

Length. 

Width. 

Length. 

Width. 
70 

44 

4* 

40 

57 

38 

4^ 

lOZ 

6o 

39 

III 

"S 

57 

30 

"5 

'«5 

48 

38 

104 

'' 

the  intercostal  sutures  are  a  few  of  the  grooves  described  by  Cope.  Fortunately  the  sutures 
between  the  bones  are  yet  open,  so  that  the  whole  structure  can  be  observed.  The  most 
striking  feature  of  the  carapace  is  the  presence  of  two  bones  in  the  region  usually  occupied  by 
the  nuchal,  a  small  anterior  and  a  large  posterior.  The  anterior  bone  (fig.  76,  ««./>),  here  regarded 
as  the  true  nuchal, has  awidth  of  52  mm.  and  a  length,  fore  and  aft,  of  30  mm.  The  other  bone, 
the  preneural  (fig.  76,  pren),  is  75  mm.  wide  and  38  mm.  long.  The  first  neural  is  pyriform, 
the  others  hexagonal,  with  the  wider  end  forward. 

The  first  three  peripheral  bones  are  each  42  mm.  high. 
Those  over  the  bridges  have  a  height  of  about  65  mm. 
There  are  6,  instead  of  5,  vertebral  scutes,  the  areas  usually 
covered  by  the  first  being  transversely  divided.  The  dimensions 
of  the  neurals  and  vertebrals  are  shown  in  the  table. 

The  nuchal  scute  is  small  and  was  probably  not  divided 

along  the  midline.    It  is  24  mm.  wide  and  10  mm.  fore  and 

aft.    The  first  marginal  is  small  and  triangular.    The  second 

has  a  length  of  25  mm.  along  the  free  border  and  a  height  of  16 

mm.    The  third  is  not  so  high.    Those  marginals  over  the 

bridge  rise  above  the  borders  of  the  costal  bones  and  have 

a  height  of  approximately  70  mm. 

A  little  of  the  hinder  border  of  the  plastron  (fig.  yy)  is  broken  away,  but  the  total  length 

was  very  close  to  415  mm.    In  general  it  resembles  the  plastron  of  species  oiBaena.    The  length 

of  the  anterior  lobe  is  113  mm.;    its  width  at  the  base,  160  mm.;  at  the  outer  ends  of  the  gulo- 

humeral  sulci,  85  mm.    The  entoplastron  is  65  mm.  long  and  45  mm.  wide.    The  symphysis  of 

the  epiplastra  is  only  14  mm.  long.  From 
the  entoplastron  the  hyoepiplastral  sutures 
run  outward  and  backward.  The  bridge 
has  a  width  of  180  mm.  The  mesoplastra 
join  at  the  midline  for  a  distance  of  20  mm., 
the  left  one  being  somewhat  the  wider. 
They  expand  outward  to  awidth  of  105  mm. 
The  length  of  the  hinder  lobe  was 
originally  about  105  mm.  Its  basal  width  is 
175  mm.;  at  the  hypoxiphiplastral  suture, 
145  mm.;  at  the  femoro-anal  sulci,  120 
mm.  The  thickness  of  the  center  of  the 
anterior  lobe  is  11  mm.  Between  the 
axillary  buttresses,  on  the  upper  surface, 
runs  a  broad  ridge  which  thickens  the  bone 
to  15  mm.  A  similar  ridge  crosses  from 
one  inguinal  buttress  to  the  other.  From 
the  latter  buttresses  a  ridge  runs  backward 
near  each  free  border  of  the  hinder  lobe,  and 
thru  these  the  thickness  is  17  mm.  The 
central  part  of  the  hinder  lobe  is  concave. 
The  skull  (plate  21,  figs.  3,  4;  plate  23,  fig.  i;  text-figs.  78-81)  of  this  specimen  is  nearly 
complete,  lacking  only  a  part  of  the  left  maxilla,  and  the  premaxillae.  At  the  time  the  writer 
publisht  his  figures  of  this  skull,  he  had  not  yet  discovered  the  differences  between  this 
specimen  and  that  numbered  5962,  described  here  as  Chisternon  undatum.  In  order  to  allow 
comparisons  the  measurements  of  the  two  skulls  are  given  in  the  table  on  p.  89. 

There  is  a  difference  of  only  5  mm.  in  the  lengths  of  the  skulls.  There  is  a  difference  of  this 
same  amount  in  the  widths  of  the  maxillae  below  the  orbits,  a  difference  of  8  mm.  in  the  widths 
of  the  skulls  at  the  quadrates,  a  difference  of  6.5  mm.  in  the  distances  from  the  orbit  to  the 
tympanic  cavity. 

The  skull  is  short,  broad  behind,  wedge-shaped  in  front.  The  temporal  region  is  broadly 
rooft  over  and  the  squamosal  comes  into  contact  with  the  parietal. 


Fig.  77. — Chisternon  hehratcum.   Plastron.     Xj.   No. 
5961  A.  M.  N.  H.     Shows  bones  and  scute  areas. 


BAENID^. 


89 


Nasals  are  present.  The  frontals  are  triangular,  with  one  apex  directed  to  the  corre- 
sponding orbit,  without  reaching  it.  The  exoccipitals  meet  in  the  midline  neither  above  nor 
below  the  occipital  foramen.  The  occipital  condyle  belongs  wholly  to  the  basioccipital.  On 
the  lower  side  of  the  skull  the  pterygoids  exclude  the  quadrates  from  contact  with  the  basioc- 
cipital and  the  basisphenoid.    The  latter  bone  does  not  quite  reach  the  vomer.    On  each  side 


Length  from  front  of  maxilla  to  occip.  condyle . . . 

Width  across  the  quadrates 

Diameter  of  tympanic  cavity 

Breadth  of  temporal  roof  from  orbit 

Diameter  of  orbit ■ 

Interorbital  space 

Breadth  of  maxilla  below  orbit 

Width  of  pterygoids 

Width  of  hinder  end  of  maxilla  from  outside  of 

cutting-edge  to  suture  with  palatine 

Orbit  to  border  of  tympanic  cavity 

Width  of  pedicel  of  quadrates  on  level  with  palate  16 


Chisternen 

Chiiternon 

hebraicuTttf 

undatum. 

No.  5961. 

No.  5962. 

67 

7» 

69 

77 

16.5 

21 

24 

29 

20 

23.5 

20 

^3 

8 

'3 

17-5 

>7-S 

II 

■5 

18.5 

^5 

of  the  basioccipital  is  a  foramen,  doubtless  for  a  vein,  wrongly  regarded  formerly  by  the 
author  as  for  the  internal  carotid  artery. 

The  choanx  are  placed  far  forward.  There  is  no  masticatory  ridge  on  the  maxilla.  Just 
within  the  rim  of  the  orbit  there  is  a  distinct  suture  which  cuts  off  the  lacrimal  from  the 
prefrontal. 

The  lower  jaw  (fig.  8i)  presents  a  rather  broad  grinding  surface. 

The  femora  of  this  specimen  are  present.  The  total  length  is  107  mm.  The  head  is 
comprest.     The  plane  passing  through  this  head  would  come  into  contact  with   the  tibial 


78. 


Figs.  78  and  79. — Chisternon  hehraicum.     Skull.     Xf .     No.  5961  A.  M.  N.  H. 

78.  Seen  from  above,    jr,  frontal;   mx^  maxilla;   na,  nasal;   pa^  parietal;   pro,  prootic;   iq,  squamosal. 

79.  Seen  from  below,    y'u,  jugal ;   mx-,  maxilla ;   /)d/,  palatine;   /)/,  pterygoid;   yu,  quadrate;   yw.  ar/,  articulation 

of  lower  jaw;    sq,  squamosal;    vom,  vomer. 

border  of  the  distal  end  of  the  bone.  In  Trachemys  elegans  this  plane  makes  an  angle  of 
perhaps  40°  with  the  axis  of  the  bone  on  the  tibial  side.  The  diameter  of  the  shaft  of  the  femur 
of  the  species  here  described  is  II  mm.    The  width  of  the  distal  end  is  31  mm. 

No.  5904  of  the  American  Museum  was  also  found  at  Grizzly  Buttes.  It  is  believed  to 
belong  to  the  present  species.  It  furnishes  a  large  shell  nearly  complete,  a  portion  of  the  skull 
and  lower  jaw,  the  neck,  the  shoulder-girdle,  and  the  complete  pelvis.  The  carapace  has  an 
axial  length  of  505  mm.,  and  a  maximum  width  of  470  mm.    The  carapace  is  moderately  convex 


9° 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


above  and  the  bridges  rise  considerably  above  the  bottom  of  the  plastron.  The  outline  of  the 
carapace  is  somewhat  pointed  in  front  and  furnisht  behind  with  rather  shallow  scallops. 
In  the  midline  behind  is  an  excavation  about  8o  mm.  wide.  As  in  the  other  carapace  the  bones 
are  rather  thin.  The  specimen  has  the  characteristics  pointed  out  by  Cope  as  distinguishing 
his  Ba'ena  hebratca,  the  presence  of  coarse  grooves  across  the  intercostal  sutures  and  the  high 
marginal  scutes  over  the  bridges.  The  bones  are  thoroly  co-ossified  and  no  certain  traces 
can  be  seen  of  the  suture  between  the  nuchal  and  the  preneural.  The  dermal  sulci  are  mostly 
distinct,  but  even  these  are  obscure  in  the  front  of  the  carapace.  The  vertebrals  are  as  in  No. 
5961.  The  marginal  below  the  front  of  the  first  costal  scute,  probably  the  fourth,  has  a  height 
of  about  35  mm.;  two  over  the  bridge  have  a  height  of  85  mm. 

The  plastron  presents  no  novel  features,  its  sutures  and  sulci  being  obscure. 

The  hinder  portion  of  the  skull  is  present,  as  well  as  the  lower  jaw.  Its  width  behind  is 
90  mm.     The  temporal  roof  extended  backward  somewhat  further  than  in  No.  5961,  but  this 


con 


pmx 


Figs.  80  and  81. — Chisternon  hebraicum.    No. 
5961A.M.N.  H.  Fig.8o,  xf.  Fig.Si.X.^ 

80.  Skull  from  right  side.  Cond,  occipital  condyle;  /r, 
frontal;  _/w,  jugal ;  lay  lacrimal;  mXf  maxilla; 
nd,  nasal ;  pa^  parietal ;  pmx,  premaxilla ;  qj, 
quadra-tojugal;  qu,  quadrate;  sq,  squamosal. 


Fig.   82.  —  Chisternon    hebraicum. 
X'i.     No.  5904  A.  M.  N.  H. 

End  views  of  third,  fourth,  sixth,  and 
eighth  cervical  vertebrae.  On  the  right 
side  the  anterior  ends;  on  the  left,  the 
hinder  ends. 


may  be  due  to  greater  age.  Over  the  brain-case  the  bone  is  9  mm.  thick.  The  lower  jaw  is 
nearly  complete.  From  the  tip  to  the  middle  of  a  line  joining  the  hinder  ends  of  the  rami  the 
distance  is  about  60  mm.  The  symphysis  measured  about  20  mm.  The  triturating  surfaces 
are  concave  in  both  directions;  their  width,  9  mm.  The  coronoid  process  stood  23  mm.  above 
the  lower  border  of  the  bone. 

The  neck  had  a  length  of  165  mm.,  about  one-half  of  the  length  of  the  dorsal  part  of  the 
column  (figs.  82,  83).  The  zygapophyses  are  high  and  not  far  removed  from  the  midline. 
There  is  a  sharp  crest  on  the  lower  midline  of  each  centrum.  The  second  and  third  are  con- 
vexo-concave; the  fourth,  biconcave;  the  fifth  to  the  eighth,  concavo-convex.  The  neural 
arches  appear  to  be  co-ossified  with  the  centra.    Fig.  84  represents  the  scapula. 

The  pelvis  is  shown  in  figs.  85  and  86.  The  ilia,  the  ischia,  the  pubes,  and  the  epipubic 
process  are  all  solidly  co-ossified.  The  expanded  upper  end  of  the  ilium  has  a  height  of  52  mm. 
and  a  width  of  42  mm.     The  posterior  articular  end  of  the  centrum  of  the    second    sacral 


BAENID-a:. 


91 


(fig.  87)  has  its  upper  half  very  little  concave,  while  the  lower  half  is  slightly  convex  and  uneven. 
The  anterior  articular  surface  of  the  first  caudal  is  decidedly  concave,  but  not  so  much  so  as  is 
the  hinder  end. 

On  the  upper  surface  of  each  xiphiplastron  is  a  depression  about  30  mm.  long  and  half  as 
wide.  The  inner  borders  of  the  two  are  55  mm.  apart.  The  tuberosities  of  the  ischia  appear 
not  to  have  fitted  into  these  depressions,  for  they  are  less  than  55  mm.  apart.    From  each  of  the 


Figs.  83-87. — Chisternon  hehraicutn 
5904  A.  M.  N.  H. 

83.  side  view  of  all  the  cervical  vertebrsc. 

ends  toward  the  left.      Xn- 

84.  Scapula.      Xi- 

81;.  Pelvis,  from  right  side.     Xi- 

86.  Pelvis,  from  below.     Xi. 

87.  Sacral  vertebrae  and  ribs.     Xj. 


tuberosities  there  projects  backward  a  long  pointed  process  that  must  have  extended  somewhat 
behind  the  hinder  border  of  the  plastron.  The  lateral  processes  of  the  pubes  rested  on  the 
hypoplastra  at  points  about  25  mm.  inside  the  free  borders  of  the  hinder  lobe. 

Genus  BOREMYS  Lambe. 

Boremys,  Lambe,  Ottawa  Naturalist,  xix,  1906,  p.  232. 

Like  Baena,  but  having  on  each  side  supramarginal  scutes,  which  alternate  with  the 
costal  scutes.    Nuchal  bone  short  and  wide.    A  preneural  present. 
Type :    Boremys  pulchra  Lambe. 


g2  FOSSIL  TURTLES   OF   NORTH   AMKRICA. 

Boremys  pulchra  Lambe. 

Figs.  88,  89. 

Baena  hatcheri,  Lambe,  Geol.  Surv.  Canada,  Contrib.  to  Canad.  Palaeont.,  Ill  (410),  pt.  2,  1902,  p.  43, 

fig.  8. 
Bdena  pulchra,  Lambe,  Ottawa  Naturalist,  xix,  1906,  p.  187,  plate  iii,  fig.  4;   pi.  iv. 
Boremys  pulchra,  Lambe,  Ottawa  Naturalist,  xix,  1906,  p.  232. 

The  type  of  the  present  species  belongs  in  the  collection  of  the  Geological  Survey  of  Canada. 
It,  together  with  at  least  one  other  specimen,  was  collected  by  Mr.  Lawrence  M.  Lambe,  of  the 
Survey,  from  beds  belonging  to  the  Belly  River  series,  equivalent  to  the  Judith  River  beds.  The 
locality  is  the  mouth  of  Berry  Creek,  on  the  Red  Deer  River,  Alberta.  The  type  consists  of 
the  anterior  half  of  the  carapace  and  the  complete  plastron.  The  other  specimen  furnishes  the 
anterior  portion  of  the  carapace  only.  Through  the  kindness  of  the  discoverer  of  the  species  the 
writer  has  had  the  opportunity  of  examining  it. 


Fig.  88. — Boremys  pulchra.     Carapace  of  type.      Xj.     From  Lambe's  figure. 
pren,  preneural;  sm,  supramarginal  scutes. 

The  specimen  was  originally  referred  to  Baena  hatcheri  for  the  reasons  that  it  was  not  then 
generally  accepted  that  the  Judith  River  formation  was  distinct  from  the  Laramie,  that  the 
specimen  is  somewhat  crusht,  that  it  resembles  in  various  ways  B.  hatcheri;  and  for  the  reason 
finally  that  the  presence  of  the  supramarginals  was  then  overlookt.  The  broader  front  of  the 
carapace  was  noted  and  caused  some  hesitation.  The  presence  of  the  supramarginals  and 
the  small  preneural  makes  the  separation  of  the  species  as  the  type  of  a  new  genus  justifiable. 

The  type  specimen  was  a  rather  small  individual,  having  close  to  three-fifths  the  length  of 
the  type  of  Baena  riparia  and  a  little  more  than  one-half  that  of  B.  hatcheri.  The  carapace 
(fig.  88)  had  a  length  of  about  195  mm.  It  is  doubtful  whether  the  width  has  been  increast 
by  the  crushing  to  which  it  was  subjected. 

The  front  of  the  carapace  is  considerably  broader  and  more  rounded  than  that  of  B. 
hatcheri.  The  neurals,  so  far  as  preserved,  appear  to  differ  in  no  important  respect.  The 
first  appears  to  be  transversely  divided  into  two  parts.  The  anterior  portion  is  to  be  regarded 
as  a  preneural,  such  as  is  seen  in  Chisternon.  The  shortness  of  the  nuchal  bone  is  remarkable. 
Whereas,  in  B.  hatcheri  and  other  specimens  oi  Baena  which  reveal  the  sutures,  the  nuchal  has 
about  the  same  fore-and-aft  length  as  the  first  neural,  in  Boremys  pulchra  the  nuchal  is  not 
one-half  as  long  as  the  neural.    Its  width  is  about  4  times  its  length. 


BAENID^. 


93 


The  scutes  in  tront  of  the  first  vertebral  are  more  symmetrically  arranged  than  in  Ba'ena 
hatcheri;  but  in  Ba'ena  and  possibly  in  Boremys  these  scutes  are  subject  to  great  variation. 
The  vertebrals  are  slightly  longer  than  broad.  In  B.  hatcheri  they  are  much  broader  than  long. 
There  is  an  accessory,  or  supernumerary,  costal  scute  on  each  side  of  the  first  vertebral.  In 
species  oi  Ba'ena  one  or  both  of  these  may  be  absent.  The  presence  of  large  supramarginals 
(fig.  88,  sm)  is  surprising.  In  Macrochelys  there  are  three  or  four  of  these  on  each  side;  but 
these  are  comparable  in  size  and  position  with  the  marginals.  In  Boremys  pulchra,  on  the 
contrary,  the  supramarginals  are  as  long  fore  and  aft  as  are  the  costals  and  alternate  with  them. 

The  plastron  (fig.  89)  has  a  length  of  about  172  mm.  The  anterior  lobe  is  slightly  narrower 
than  that  of  B.  hatcheri.  The  entoplastron  is  long  and  narrow.  The  bridge  is  somewhat 
narrower  relatively  to  the  length  of  the  plastron  than  in  B.  hatcheri.  The  mesoplastra  join 
along  the  midline  for  a  space  of  about  14  mm.  The  hinder  lobe  seems  to  differ  little  from  that 
of  the  species  just  mentioned.  The  intergulars  are  small  and  do  not  reach  back  on  the  ento- 
plastron, thus  differing  from  those  of  5.  hatcheri. 


Fig.  89. — Boremys  pulchra.     Plastron  of  type.      X^.     From  Lambe's  figure. 
Genus  NEURANKYLUS  Lambe. 

A  genus  of  uncertain  position  and  known  only  from  a  portion  of  the  carapace  of  the  type 
species.  Eighth  neural  large,  followed  by  an  expanded  suprapygal.  In  the  type  a  ninth  pair 
of  costal  bones.    The  vertebral  scutes  nearly  twice  as  wide  as  long. 

Type:  Neurankylus  eximtushambe. 

This  genus  is  placed  provisionally  in  the  Ba'enidce.  When  the  last  neural  of  Neurankylus 
eximius  is  compared  with  that  of  Ba'ena  riparia  they  are  seen  to  be  very  similar.  The  pre- 
ceding neural  in  the  latter  species  is  elongated  and  appears  to  occupy  the  place  of  two  neurals; 
and  it  is  possible  that  the  sixth  and  seventh  neurals  of  Lambe's  figures  were  consolidated.  The 
presence  of  the  ninth  pair  of  costals  is  probably  an  individual  variation  and  of  no  classificatory 
value,  as  suggested  by  the  Yale  specimen  oi Echmatemys  wyomingensis{'Le^iAy),v!\\'ic\\  possesses 
ten  pairs  of  costals.  The  very  broad  vertebral  scutes  indicate  that  the  genus  is  distinct 
from  Ba'ena.  Mr.  Lambe  placed  the  genus  provisionally  among  the  Chelydridx,  but  as  no 
genera  of  this  family  are  known  from  deposits  older  than  the  Tertiary  and  as  the  type  has  some 


94 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


resemblances  to  the  Ba'enida,  which  flourisht  at  that  time,  it  seems  better  to  refer  Neurankylus 
to  this  family  until  more  is  known  about  it. 

Neurankylus  eximius  Lambe. 

Neurankylus  eximius,  Lambe,  Contrib.  Canad.  Palaeont.,  lii  (4  to),  1902,  p.  42,  fig.  7. 

The  remains  on  which  this  species  was  based  were  collected  by  Mr.  Lawrence  M.  Lambe 
in  1901,  from  Judith  River  deposits,  Belly  River  series,  on  Red  Deer  River,  Alberta.  They 
consist  of  the  costals  of  the  third  pair;  the  right  fourth;  the  left  fifth,  sixth,  seventh,  eighth, 
and  the  supernumerary  ninth;  the  most  posterior  neural;  and  the  suprapygal.  No  peripheral 
bones  were  secured.  The  individual  appears  to  have  had  a  carapace  360  mm.  long.  The 
eighth  neural  is  elongated  and  wider  behind  than  in  front.     It  articulates  laterally  with  the 


Fig.  90. — Neurankylus  eximius.     Hinder  portion  of  carapace  of  type. 
From  Lambe's  figure.     Xj. 

c.  p.  3,  c.  p.  4,  etc.,  costal  plates;  n.  3,  n.  4,  etc.,  neural  plates;  spy,  suprapygal. 

costals  of  the  seventh,  eighth,  and  ninth  pairs.  The  posterior  neural  of  Baena  riparia  artic- 
ulates with  the  seventh  and  eighth  pairs  of  costals.  The  suprapygal  of  Neurankylus  eximius 
was  probably  followed  by  a  pygal. 

The  vertebral  scutes  are  relatively  broad,  the  third  being  nearly  twice  as  wide  as  long. 
The  sides  are  bracket-shaped.  The  costo-marginal  sulci  evidently  ran  along  on  the  peripheral 
bones.    The  costal  scutes  had  relatively  little  height. 

Mr.  Lambe  states  that  no  very  decided  sculpture  is  shown  on  the  surface  of  the  bones. 
Striations  occur  adjoining  and  at  right  angles  with  the  sutures;  elsewhere,  especially  near  the 
proximal  ends  of  the  costals,  there  is  some  roughness,  produced  by  small,  obscure,  and  irregular 
depressions.  On  two  of  the  costals  there  occur  some  comparatively  large,  concentrically 
curved  groove-like  markings. 

Genus  THESCELUS  nov. 

Carapace  with  an  enamel-like  surface,  which  is  sculptured  into  raised  dots  and  lines,  the 
latter  irregular  in  length  and  direction,  with  intervening  pits  and  valleys.  The  front  of  the 
carapace  shortened  and  excavated  in  the  midline;  the  rear  somewhat  pointed.  The  plastron 
like  that  of  Baena.     Bridges  broad,  extending  far  forward.     The  buttresses  feebly  developt. 

Type :    Thescelus  insiliens  Hay. 

The  bridges  of  the  members  of  this  genus  extend  far  forward,  so  that  the  opening  for  the 
head  and  fore  legs  is  narrowed.    The  movements  of  the  fore  legs  must  have  been  a  good  deal 


BAENIDiS. 


95 


restricted.  On  the  other  hand,  the  openings  for  the  hind  legs  were  large.  It  seems  probable 
that  these  turtles  were  accustomed  to  lying  in  the  water  in  wait  for  passing  victims  and 
leaping  on  them  and  seizing  them.    The  hinder  limbs  were  probably  large  and  strong. 

Quaere  alium,  tua  quem  moveant  miracula,  dixit 
Thescelus;   utque  manu  jaculum  fatale  parabat 
Mittere,  in  hoc  hsesit  signum  de  marmore  gestu. 

— Ovid,  Mel.,  V,  i8l. 
Thescelus  insiliens  sp.  nov. 
Plates  24,  25. 

The  basis  of  this  species  is  a  specimen  which  was  collected  for  the  American  Museum  of 
Natural  History  by  Mr.  Barnum  Brown,  in  1900,  in  the  Laramie  beds  of  Wyoming.  The 
locality  more  accurately  stated  is  on  Seven  Mile  Creek,  about  5  miles  north  of  the  Cheyenne 
River,  and  about  40  miles  west  of  the  town  of  Edgemont,  South  Dakota. 

The  specimen  is  a  very  complete  one,  presenting  both  the  carapace  and  the  plastron.  The 
carapace  is  in  some  parts,  especially  at  the  peripherals  over  the  bridges,  considerably  fractured. 
Very  few  parts  are,  however,  missing,  and  the  form  and  the  general  structure  can  be  deter- 
mined.   Unfortunately,  both  the  bone  and  the  matrix  filling  the  interior  are  very  friable. 

Traces  of  the  sutures  between  the  costals  are  present  and  have  been  indicated  in  the  figures. 
It  has  been  found  impossible  to  determine  the  boundaries  of  the  neurals.  Faint  traces  of  the 
sutures  have  lead  to  the  provisional  delimitation  of  the  nuchal  bone.  The  first  peripherals  are 
probably  correctly  represented.  It  is  believed  also  that  the  sutures  between  the  various  bones 
of  the  plastron  are  correctly  determined,  where  indicated  definitely.  The  form  and  extent  of 
the  epiplastra  and  entoplastron  are  conjectural,  as  no  traces  of  the  sutures  can  be  made  out. 

The  form  of  this  turtle  is  rather  remarkable.  Seen  from  above,  the  shell  resembles  that  of 
Caretta  caretta.  It  is  broad,  not  greatly  elevated,  with  a  median  frontal  excavation  for  the 
neck,  and  narrowed  behind.  The  plastron  resembles  greatly  that  of  the  species  of  Baena. 
It  extends,  however,  far  beyond  the  front  of  the  carapace,  while  it  fails  equally  as  much  to 
reach  the  hinder  border  of  the  carapace.    The  bones  are  thin. 

The  length  of  the  carapace  (plate  24)  in  the  midline  is  397  mm.  The  first  peripherals 
extend  21  mm.  in  front  of  the  bottom  of  the  anterior  excavation;  thus  the  total  length  is  418  mm. 
The  greatest  breadth,  across  the  middle,  is  also  397  mm.  The  height  above  the  plastron  is 
140  mm.,  but  in  life  it  has  evidently  been  somewhat  greater. 

From  the  ends  of  the  axis  of  greatest  width  the  border  of  the  carapace  curves  forward  to 
the  anterior  excavation.  Passing  backward  from  the  axis  referred  to,  the  border  is  at  first 
very  slightly  concave  to  just  behind  the  inguinal  notches;  then  rather  strongly  convex  for  some 
distance;  then  again  rather  strongly  concave;  at  length  convex  to  the  midline  behind.  The 
last  concavity  in  the  border  would  be  over  the  hind  legs,  when  extended  backward.  Beyond 
the  sinuosities  mentioned,  there  are  no  notches,  scallops,  nor  indentations  in  the  free  borders  of 
the  carapace.  The  edge  of  the  shell  just  behind  the  inguinal  notches  appears  to  have  been 
somewhat  flared  upward;  but  this  appearance  may  be  due  to  some  distortion. 

In  the  hinder  region  of  the  carapace  the  peripherals  are  about  7  mm.  thick  and  with  acute 
free  borders.  As  the  border  of  the  carapace  is  followed  forward,  it  becomes  more  obtuse.  The 
nuchal  and  the  first  peripherals  are  about  9  mm.  thick.  There  are  nowhere  any  carinse  or 
bosses  on  either  the  carapace  or  the  plastron. 

The  whole  surface  of  the  carapace  is  covered  with  a  hard,  enamel-like  layer,  like  that  of 
Compsemys,  Glyptops,  and  Trtonyx.  The  ornamentation  consists  of  raised  dots  and  lines. 
The  latter  are  sometimes  straight,  sometimes  bent,  or  brancht,  or  anastomosing.  The  general 
effect  is  that  of  shagreened  leather.  On  each  side  of  the  sutures  between  the  costals  a  band  of 
the  surface  is  striated  at  right  angles  with  the  suture.  It  is  from  this  striation,  when  present, 
that  the  position  of  the  sutures  can  be  made  out.  Near  the  rear  of  the  carapace  there  are  such 
indications  of  sutures  as  to  justify  the  outlining  of  a  suprapygal  similar  to  that  of  Glyptops 
plicatulus. 

The  anterior  portion  of  the  carapace  is  unusually  short,  the  abbreviation  being  at  the 
expense  of  the  first  costals,  the  anterior  peripherals,  and  the  nuchal.  The  form  and  position 
of  the  latter  are  indicated  provisionally,  but  there  seems  to  be  sufficient  evidence  to  show  that 


q6  fossil   turtles    of    north    AMERICA. 

its  anteio-posterior  extent  was  only  about  30  mm.  Were  the  anterior  excavation  not  present, 
the  fore-and-aft  extent  of  the  nuchal  would  be  about  normal. 

The  first  peripheral  has  a  fore-and-aft  extent  of  about  43  mm.  Its  length,  parallel  with  the 
border,  can  not  be  accurately  determined;  it  was  about  65  mm.  From  this  specimen  it  can  not 
be  learned  where  the  sutures  between  the  costal  and  the  peripheral  bones  were  situated,  except 
in  the  case  of  the  first  peripherals.  However,  since  in  both  Glyptops  and  Ba'ena  these  sutures, 
over  the  bridges,  follow  the  sulci  between  the  costal  and  marginal  scutes,  it  is  probable  that 
they  do  so  in  Thescelus.  In  Glyptops  plicatulus,  behind  the  bridges,  the  sutures  rise  a 
considerable  distance  above  the  epiderrtial  sulci;  in  Ba'ena  emilice,  a  very  little  above.  In 
Thescelus  insiliens  the  structure  of  the  surface  of  the  bone  appears  to  indicate  that  behind  the 
bridges  the  sutures  are  placed  somewhat  above  the  scutal  sulci,  and  they  are  accordingly  so 
represented  provisionally. 

The  number  and  the  extent  of  the  peripherals  along  the  border  can  not  be  made  out  with 
certainty. 

The  epidermal  scutes  and  their  limits  are  for  the  most  part  determinable.  The  sulci  are 
narrow  and  shallow,  but  usually  distinct.  The  first  vertebral  is  60  mm.  long  in  the  midline, 
concave  in  front,  behind,  and  on  each  side.  The  width  behind  is  75  mm.,  but  in  front  it  is 
expanded  to  98  mm.  The  next  three  vertebrals  are  from  90  mm.  to  95  mm.  wide.  The  exact 
limit  between  the  fourth  and  the  fifth  can  not  be  determined.  The  fifth  vertebral  is  i  lomm.  wide. 

There  seems  to  have  been  no  nuchal  scute.  The  first  marginal  on  each  side  is  very  narrow, 
8  mm.  to  10  mm.,  and  extends  along  the  free  border  of  the  carapace  30  mm.  The  succeeding 
marginals  increase  in  height  and  length  to  the  fourth,  which  is  55  mm.  high  and  occupies 
85  mm.  of  the  free  border.  The  succeeding  marginals  retain  this  width  to  beyond  the  inguinal 
notch;   the  posterior  are  much  narrower.     There  were  probably  paired  supracaudal  scutes. 

The  plastron  (plate  25)  has  a  median  length  of  420  mm.  The  anterior  lobe  has  a  length  of 
117  mm.  The  base  is  170  mm.  wide,  but  the  lobe  narrows  forward  so  rapidly  that  at  the 
crossings  of  the  gular  sulci  the  width  is  only  91  mm.  The  posterior  lobe  is  no  mm.  long, 
168  mm.  wide  at  the  base,  and  130  mm.  wide  at  the  ends  of  the  femoro-anal  sulci.  The 
posterior  end  is  broad,  and  occupied  by  a  wide  emargination  10  mm.  deep. 

The  bridge  is  194  mm.  wide,  fore  and  aft.  From  its  inner  end  to  the  border  of  the  carapace 
is  about  120  mm. 

The  sutures  bounding  the  epiplastron  and  the  entoplastron  are  not  demonstrable;  hence 
they  are  represented  provisionally.     The  thickness  of  the  epiplastra  is  about  9  mm. 

There  are  very  broad  mesoplastra  extending  across  the  plastron.  The  width  of  the  outer 
end  of  each  bone  is  about  100  mm.,  being  apparently  a  little  greater  on  one  side  than  on  the 
other.  Where  the  bones  meet  at  the  midline  they  are  54  mm.  wide.  These  mesoplastra  differ 
from  those  oiGlyptops  in  being  proportionally  larger  and  in  having  their  median  ends  narrower 
than  the  outer.    They  are  much  like  those  oi Ba'ena  emilta. 

The  extent  of  the  hyoplastra  along  the  midline  equals  about  105  mm.;  that  of  the  hypo- 
plastra  100  mm.  The  anterior  borders  of  the  xiphiplastra  run  straight  across  the  plastron, 
except  near  the  border  of  the  plastron,  where  they  send  forward  on  each  side  an  angular 
process  into  the  hypoplastron.  Just  behind  this  process  the  xiphiplastron  is  10  mm.  thick; 
near  the  hinder  end,  6  mm. 

The  intergulars  and  gulars  of  this  species  are  much  like  those  of  Ba'ena  emilia.  The 
former,  taken  together,  extend  30  mm.  from  side  to  side;  16  mm.  fore  and  aft.  The  gulars  are 
very  large,  the  sulci  bounding  them  behind  meeting  the  midline  54  mm.  behind  the  front  of 
the  plastron,  and  diverging  with  an  angle  of  about  140°.  If  the  entoplastron  has  been  even 
approximately  defined,  the  humero-pectoral  sulcus  falls  far  behind  it.  The  fore-and-aft 
extent  of  the  humerals  along  the  midline  is  87  mm.  The  sulci  between  the  pectorals  and  the 
abdominals  are  deflected  backward  near  the  midline  on  each  side.  The  pectorals  occupy  only 
55  mm.  of  the  midline.  The  femorals  are  60  mm.  fore  and  aft;  the  anals  72  mm.  The  femoro- 
anal  sulci  are  directed  far  forward  as  they  approach  the  midline,  exactly  as  in  Ba'ena. 

On  the  bridge  there  are  4  large  inframarginals  whose  boundaries  have  been  satisfactorily 
determined. 

The  buttresses  of  the  plastron  are  intermediate,  in  extent  of  development,  between  those  ot 
Glyptops  and  Ba'ena. 


BAENID^. 


97 


Thescelus  rapiens  sp.  nov. 

Figs.  91,  92. 

This  species  is  represented  by  a  single  shell,  which  was  collected  from  Laramie  deposits, 
at  Ojo  Alamo,  San  Juan  County,  New  Mexico,  in  1904,  by  Mr.  Barnum  Brown,  of  the 
American  Museum  of  Natural  History.  The  catalog  number  of  the  specimen  is  6066. 
The  shell  has  been  damaged  considerably  by  weathering,  and  lacks  a  portion  of  the  carapace 
in  the  nuchal  region,  some  portions  of  the  right  costals,  most  of  the  peripherals,  the  front  of  the 
plastron,  and  the  rear  of  the  xiphiplastrals. 

The  length  of  the  carapace  must  have  been  close  to  400  mm.;  the  width  about  375  mm. 
Apparently  the  shell  was  considerably  deprest.  The  front  of  the  carapace  over  the  neck  was 
excavated,  but  not  so  deeply  as  in  T.  instUens.  The  area  occupied  by  the  vertebral  scutes 
presents  a  broad,  shallow  longitudinal  channel;  but  in  this,  over  the  neural  bones,  there  is  a 
low  ridge.    The  free  borders  of  the  anterior  peripherals  are  rather  obtuse. 

The  sutures  of  the  shell  are  obliterated,  but  a  few  of  them  may  be  traced  by  the  fine  stria- 
tions  which  cross  them.     So  far  as  they  can  be  made  out,  they  are  shown  in  the  diagrammatic 


92. 


Figs.  91  and  92. — Thescelus  rapiens.     Carapace  and  plastron.     Type.      xj. 
91.  Carapace.  92.  Plastron. 

figures.  The  scutal  areas  are  distinctly  markt  on  the  shell.  They  present  various  irregularities. 
The  vertebrals  (fig.  91)  are  broader  than  long;  their  dimensions  are  shown  in  the  table 
on  page  98. 

On  the  left  side  there  is  a  supernumerary  costal  scute.  This  has  been  cut  off  mostly  from 
the  first  costal  proper,  but  to  some  extent  from  the  second  marginal.  The  fourth  marginal, 
shown  on  the  left  side,  has  a  height  of  57  mm.,  rising  somewhat  on  the  costals. 

The  plastron  (fig.  92)  is  large.  From  a  low  ridge  which  joins  the  free  border  of  the  front 
lobe  with  that  of  the  hinder  lobe  the  bridges  ascend  at  an  angle  with  the  remainder  of  the 
plastron.  The  axillary  notch  is  far  forward,  falling  about  55  mm.  behind  the  front  of  the 
carapace.  The  opening  for  the  head  and  legs  is  thus  considerably  restricted.  The  front  lobe 
extended  evidently  much  beyond  the  front  of  the  carapace.    Its  length  can  not  be  determined. 

7 


98' 


FOSSIL   TURTLES    OK    NORTH    AMERICA. 


Vertebral. 

Length . 

Width. 

I 

5o± 

8i± 

2 

75 

92 

3 

81 

92 

4 

61 

92 

5 

• 

86 

The  width  of  the  base  is  150  mm.    The  bridge  is  167  mm.  wide    The  length  of  the  hinder  lobe 

was  approximately  100  mm.;    the  width  at  the  base  is  165  mm.     It  narrows  rather  rapidly 

backward,  so  that  at  the  femoro-anal  sulcus  the  width  is  104  mm. 

There  are  present  large  mesoplastra,  the  boundaries  of  which  can  be  pretty  satisfactorily 

determined.    These  are  about  35  mm.  wide  at  the  midline,  but  they  expand  to  about  85  mm. 

at  the  peripherals. 

The  median  longitudinal  sulcus  runs  a  very  irregular  course,  and  across  the  femorals  it 

can  not  be  distinguisht  with  certainty.     The  humerals  occupy  70  mm.  of  the  midline;  the 

_^ pectorals,  about  90  mm.;  the  abdominals,  about  35  mm.;    the 

femorals,  about  52  mm.  The  femoro-anal  sulcus  runs  far  forward 
from  its  starting  point  on  the  border  of  the  plastron.  Probably  on 
account  of  weathering,  the  sculpture  of  the  carapace  is  nearly 
obliterated,  appearing  only  in  a  few  spots.  On  the  plastron  it  is 
more  distinct.  It  appears  to  have  resembled  that  of  T .  insihens 
and  consists  of  narrow  and  low  ridges  and  tubercles.  Some  traces 
are  observed  of  the  ridges  due  to  the  growth  of  the  scutes. 

This  species  differs  from  T.  insiltens  in  having  the  nuchal 

less  deeply  excavated,  in  having  a  median  depression  along  the  back,  and  in  having  the  hinder 

lobe  of  the  plastron  more  rapidly  reduced  in  width  backward.    In  T.  insilietis  the  bridges  are 

considerably  wider  than  the  base  of  the  hinder  lobe. 

Genus  CHARITEMYS  nov. 

A  genus  of  Baenidae.  So  far  as  known  like  Thescelus,  but  with  the  axillary  buttresses 
ascending  to  near  the  neural  borders  of  the  first  costals.  Inguinal  buttresses  probably  ascend- 
ing on  inner  surfaces  of  the  fifth  and  sixth  costals,  but  not  to  so  great  a  height  as  did  the  axillary 
buttresses. 

Type:   Charitemys  captans  Hay. 

Charitemys  captans  sp.  nov. 
Telt-figs.  93-95- 

The  type  of  the  present  species  is  No.  6098  of  the  American  Museum  of  Natural  His- 
tory. It  forms  a  part  of  the  Cope  collection  of  fossil  reptiles  and  was  collected  in  1876,  by 
Messrs.  Sternberg  and  Isaac,  in  the  Judith  River  deposits  of  Montana.  There  are  present 
considerable  parts  of  both  the  carapace  and  the  plastron,  but  unfortunately  important  parts 
are  missing. 

In  size  this  species  appears  to  have  been  somewhat  smaller  than  the  type  of  Thescelus 
insiltens,  judging  from  the  plastral  bones,  but  of  the  same  size,  if  we  judge  from  the  widths  of 
6  costal  bones. 

Of  neurals  there  are  portions  of  only  two.  One  of  these,  probably  the  eighth,  has  a  width 
of  44  mm.  Its  length  can  not  be  determined,  what  is  regarded  as  the  posterior  end  being 
broken  away.  On  the  supposed  anterior  end  is  a  rounded  carina.  The  broader  end  is  crost 
by  a  sulcus,  probably  that  between  the  fourth  and  the  fifth  vertebral  scutes.  On  the  under  side 
are  three  impressions  for  three  neural  spines.  The  other  neural  is  only  30  mm.  wide.  It 
probably  belonged  near  the  beginning  of  the  series. 

Of  the  costals  there  are  present  the  proximal  end  of  the  first  of  the  left  side,  the  right 
second,  third,  and  sixth,  and  the  left  fourth,  fifth,  sixth,  and  seventh.  Fig.  93  represents  the 
second  and  third  right  costals;  fig.  94,  the  fourth  to  the  seventh  of  the  left  side.  Of  the  latter 
three,  more  or  less  of  the  distal  ends  are  missing.  The  supposed  first  presents  difficulties. 
On  the  upper  surface  are  found  portions  of  the  first  and  second  scute  areas  and  of  the  first 
costal  area.  The  area  of  the  first  vertebral  scute  on  this  costal  is  only  16  mm.  wide.  The 
whole  width  of  this  scute  could  hardly  have  exceeded  65  mm.  On  the  lower  side  is  a  large  tri- 
angular articular  scar  for  the  axillary  buttress  of  the  plastron.  This  approacht  within  21 
mm.  of  the  neural  border  of  the  costal.  Between  the  scar  and  the  neural  border  is  a  sharp 
ridge  from  which  appears  to  have  been  broken  the  rib-head  of  the  costal.  This  was  much 
slenderer  than  those  of  the  succeeding  costals.    The  slenderness  of  this  rib-head  was  hardly  to 


BAENID^. 


99 


have  been  expected.  There  is  present  a  portion  of  one  plastral  buttress,  the  length  of  which  is 
72  mm. ;   but  this  has  the  appearance  of  being  the  inguinal  buttress. 

The  second  costal  (fig.  93)  has  a  length  of  142  mm.,  a  width  of  54  mm.  at  the  costo-vertebral 
sulcus,  and  of  60  mm.  at  the  distal  end.  The  proximal  end  is  crost  by  the  sulcus  bounding 
laterally  the  second  vertebral.  This  had  a  width  of  about  no  mm.  Anteriorly  it  narrowed 
considerably.  Its  anterior  end  occupied  only  18  mm.  on  the  first  costal  plate.  The  distal  end 
of  the  costal  is  crost  by  the  costo-marginal  sulci,  a  condition  showing  that  the  fourth  and  fifth 
marginal  scutes  overlapt  on  the  costal  bone. 

The  third  costal  plate  (fig.  93)  is  slightly  narrower  than  the  second  at  the  proximal  end  and 
wider  than  the  latter  at  the  distal  end.  The  fifth  and  sixth  marginal  scutes  overlapt  slightly 
on  the  distal  end.  The  proximal  end  was  occupied  by  a  part  of  the  second  and  a  small  part  of 
the  third  vertebral  scutes.  The  fourth  left  costal  (fig.  94)  is  48  mm.  wide  at  the  costo-vertebral 
sulcus;  66  mm.  at  the  distal  end.  That  portion  of  the  third  vertebral  scute  on  the  proximal 
end  of  this  costal  is  48  mm.  wide.    The  costo-marginal  sulcus  skirts  along  the  distal  end  of  the 


Figs.  g^-g^.—Charitemys  captans.     Costal  bones  and  plastron  of  type.     Xj. 

93.  Second  and  third  right  costals,  the  second  on  the  right.  94.  Fourth  to  seventh  costals  of  left  side. 

95.  Plastron  considerably  restored. 

bone.  The  fourth  and  fifth  costals  are  each  45  mm.  wide.  Of  the  seventh  there  is  present  a 
fragment  46  mm.  long  and  31  mm.  wide  at  the  sulcus.  The  rib-heads  of  the  fifth  and  sixth 
costals  have  a  diameter  of  about  6  mm.  No  trace  of  the  articulation  for  the  inguinal  buttress 
appears  on  the  parts  preserved  of  the  fifth  and  sixth  costals.  It  is  evident,  therefore,  that  this 
buttress  did  not  ascend  to  as  high  a  point  as  did  the  axillary.  From  the  form  of  the  sutural 
border  of  the  supposed  inguinal  buttress  it  is  believed  that  the  latter  was  articulated  to  the 
fifth  and  sixth  at  their  junction. 

Of  the  plastron  (fig.  95)  there  are  present  a  fragment  of  the  left  epiplastron,  a  large  part 
of  the  right  hyoplastron,  the  left  hypoplastron,  and  a  portion  of  the  free  border  of  the  right 
xiphiplastron.    These  are  represented  in  the  diagrammatic  figure. 

That  this  turtle  possest  a  mesoplastron  is  evident;  otherwise,  the  bridges  would  have  been 
only  about  100  mm.  wide,  about  one-half  as  wide  as  the  costals  spanned  by  the  two  buttresses 
of  one  side.  No  part  of  the  mesoplastrals  appears  to  be  included  among  the  bones  present. 
Their  antero-posterior  width  is  only  conjectural. 


lOO  FOSSIL   TURTLES   OF    NORTH    AMERICA. 

The  piece  of  epiplastron  present  is  9  mm.  thick.  The  gulo-humeral  sulcus  crosses  the 
hinder  end  as  in  Glyptops  and  Ba'ena. 

The  length  of  the  hyoplastron,  from  the  epiplastral  suture  to  the  mesoplastron,  is  120  mm. 
The  width  of  the  anterior  lobe  was  about  142  mm.  The  distance  from  the  axillary  notch  to 
the  mesoplastron  measured  very  close  to  50  mm.  The  thickness  of  the  bone  at  the  entoplastral 
suture  is  6  mm.  The  free  border  in  front  of  the  axillary  notch  is  subacute.  Most  of  the  border 
which  rose  to  meet  the  peripherals  is  broken  away.  A  portion  of  the  sulcus  between  the 
abdominal  scute  and  the  anterior  inframarginal  is  present. 

The  length  of  the  hypoplastral  at  the  midline  is  90  mm.;  the  width  at  the  base  of  the 
hinder  lobe,  80  mm.;  the  width  from  the  midline  to  the  union  with  the  bridge  peripherals, 
130  mm.  A  portion  of  the  outer  end  of  the  bone  is  missing,  but  a  section  of  the  sulcus  is  seen 
starting  forward  from  the  inguinal  notch  and  section  of  another  sulcus  between  the  hinder 
inframarginal  and  the  contiguous  marginals.  The  hinder  inframarginal  has  a  width  of  about 
45  mm.    Its  anterior  end  appears  to  have  extended  on  the  mesoplastron. 

The  fragment  of  xiphiplastral  is  53  mm.  long.  It  shows  the  free  border.  This  is  subacute, 
and  from  it  the  bone  thickens  soon  to  10  mm.  No  portion  of  the  upper  surface  was  covered 
with  scutes.  On  the  lower  surface  the  femoro-anal  sulcus  crost  the  bone  about  30  mm.  behind 
the  suture  with  the  hypoplastron.  The  form  of  the  hinder  border  of  the  lobe  can  not  be 
determined. 

Of  the  skull  there  is  present  the  pedicel  of  the  left  quadrate.  The  condyle  for  the  lower 
jaw  is  concave,  1 1  mm.  from  side  to  side,  and  less  than  5  mm.  antero-posteriorly.  At  the  inner 
side  of  this  condyle  there  ascends  toward  the  lower  end  of  the  parietal  plate  a  sharp  ridge.  The 
rough  surface  for  the  pterygoid  lacks  8  mm.  of  reaching  the  condyle,  a  fact  that  shows  that 
this  genus  did  not  belong  to  the  Pleurodira. 

The  upper  surface  of  the  carapace  was  more  or  less  uneven,  especially  along  the  midline. 
All  the  articular  borders  of  the  bones  are  striated  perpendicularly  to  the  sutures.  Besides  this, 
there  is  a  delicate  pitting  of  the  surface  which  gives  the  effect  of  leather.  The  lower  halves 
of  the  costals  are  markt  by  coarse  ridges,  which  have  been  produced  during  the  growth  of  the 
costal  scutes. 

The  plastral  bones  have  all  the  sutures  conspicuously  markt  by  striae,  which  run  at  right 
angles  with  the  sutures.    The  whole  surface  is  occupied  by  a  fine  network  of  delicate  lines. 

Genus  POLYTHORAX  Cope. 

An  insufficiently  known  genus  of  uncertain  position.  Plastron  suturally  united  with  the 
carapace;  furnisht  with  the  usual  scutes,  besides  intergulars  and  interhumerals.  Lower  jaw 
with  narrow  ramus;  the  triturating  surface  bounded  outwardly  by  a  sharp  margin;  the 
symphysis  short. 

Type:    Polythorax  missurtensis  Cope. 

This  genus  is  arranged  provisionally  among  the  Baenidae;  but  it  is  probable  that  it  and 
Archceochelys  Lydekker  belong  to  a  distinct  family. 

Polythorax  missuriensis  Cope. 

Polythorax  missuriensis,  CoPE,  Proc.  Acad.  Nat.  Sci.  Phiia.  1876,  p.  258;  Bull.  U.  S.  Geo),  and  Geog. 
Surv.  Terrs.,  Ill,  1877,  p.  573. — Hay,  Bibliog.  and  Cat.  Yoss.  Ven.  N.  A.,  1902,  p.  438. — Hatcher, 
Bull.  U.  S.  Geol.  Surv.  257,  1905,  p.  77. 

It  is  not  at  present  known  what  has  become  of  the  type  of  this  species.  It  was  found  in  the 
Judith  River  deposits  of  Montana,  in  1876.  The  plastron  appears  to  have  been  pretty  complete, 
but  we  are  not  told  how  much  of  the  carapace  was  secured.  No  part  of  the  species  has  ever 
been  figured. 

The  plastron  had  a  total  length  of  183  mm.;  hence  the  individual  was  not  a  large  one, 
perhaps  attaining  about  the  size  of  our  Trachemys  elegans.  The  anterior  lobe  had  a  length  of 
49  mm.  The  bridge  was  76  mm.  wide  and  as  long.  The  anterior  lobe  is  stated  to  have  been 
narrower  at  the  base  than  the  bridge.  We  must  conclude  therefore  that  this  lobe  was  not  one- 
third  as  wide  as  the  carapace.     Its  anterior  extremity  was  rounded.    The  width  of  the  base  of 


BAENID^..  lOI 

the  hinder  lobe  is  not  given,  but  its  posterior  extremity  was  35  mm.  wide,  truncated,  and 
with  rounded  angles.  It  was  shorter  than  the  anterior  lobe.  Its  thickness  in  the  inguinal 
region  was  10  mm. 

The  surface  of  the  plastron  was  obsoietely,  but  coarsely,  rugose;  roughest  in  front,  where 
the  sculpture  consisted  of  short,  raised  lines  irregularly  disposed. 

The  intergulars  were  distinct.  These  were  followed  by  a  pair  of  interhumerals,  which  were 
longer  than  wide  and  crowded  the  humerals  away  from  each  other,  and  they  seem  to  have 
extended  themselves  backward  between  the  pectorals  likewise.  The  pectoro-humeral  sulcus 
appears  to  have  been  advanced  well  forward.  Cope  states  that  it  was  impossible  to  determine 
whether  or  not  "intermarginal "  scutes  were  present,  and  that  if  they  existed  their  position  was 
quite  external.    It  is  probable  that  by  "intermarginals"  was  meant  inframarginals. 

The  carapace  is  stated  to  have  possest  an  openly  dentate  posterior  border.  The  surface 
was  irregularly  swollen,  especially  along  the  margins  of  the  vertebral  scutes.  The  latter  were 
wide;  the  marginals  are  said  to  be  narrow,  by  which  is  probably  meant  that  they  rose  but  a 
short  distance  from  the  free  margins. 

The  description  of  this  species  given  by  Cope  indicates  that  it  was  related  to  Ba'ena  rather 
than  to  Adocus.  The  thoro  co-ossification  of  the  bones,  so  that  the  presence  of  mesoplastrals 
could  not  be  proved  or  disproved,  the  uneven  surfaces  of  the  shell,  the  notcht  border  of  the 
carapace,  all  point  toward  Ba'ena.  At  the  same  time,  the  presence  of  the  interhumerals 
marks  it  off  as  different  from  all  North  American  turtles  hitherto  described.  Archceochelys 
(Lydekker,  Cat.  Foss.  Rept.,  pt.  in,  1889,  p.  219),  from  the  Wealden  of  England,  has  the 
humerals  separated  by  what  has  been  regarded  as  an  intergular,  but  which  is  quite  as  likel\' 
an  interhumeral.  Behind  this  come  in  succession  an  interpectoral,  an  interabdominai. 
and  an  interfemoral.  The  latter  extends  itself  backward  between  the  anals  also.  That  is,  the 
scutes  which  usually  join  in  pairs  along  the  median  line  are  here  separated  the  length  of  the 
plastron  by  a  series  supposed  to  be  azygous.  These  median  scutes  in  both  Polythorax  and 
Archceochelys  are  probably  homologous  with  the  median  series  o( Dermochelys. 

Mr.  Lydekker  places  his  genus  provisionally  in  the  Amphichelydia. 

Genus  NAOMICHELYS  nov. 

A  genus  known  only  from  the  entoplastron.  Outer  surface  ornamented  with  elevations 
resembling  small  shot.  A  long  narrow  scute  (intergular  or  interhumeral)  occupies  most  of  the 
length  of  the  bone.    Gulars  ?  and  humerals  ?  present. 

Type:    N aomtchelys  speciosci  Hay. 

The  relationships  of  this  genus  are  not  certain.  It  may  belong  among  the  Pleurosternidx 
rather  than  among  the  Baenidx.    It  is  here  put  in  the  vicinity  o{ Polythorax. 

Naomichelys  speciosa  sp.  nov. 

Plate  40,  figs.  2,  5. 

The  only  portion  of  this  species  at  present  known  is  an  entoplastron  which  was  collected 
in  1904,  by  Mr.  Barnum  Brown,  of  the  American  Museum  of  Natural  History.  It  was  secured 
in  the  Upper  Jurassic,  Morrison  beds,  25  miles  east  of  Pryor,  Montana.  The  catalog  number 
is  6136.  The  bone  is  complete,  except  that  the  extreme  anterior  end  is  broken  away.  The  bone 
is  85  mm.  long,  and  was  originally  about  10  mm.  longer.  The  width  is  78  mm.  The  thickness 
is  quite  uniformly  close  to  7  mm.  Where  the  bone  joined  the  epiplastra  the  upper  surface 
extends  out  a  little  farther  than  the  lower.  The  hyoplastrals  overlapt  extensively  the  ento- 
plastron, as  may  be  seen  from  plate  42,  fig.  3.  Fig.  2  of  the  same  plate  shows  the  scutes  and 
the  ornamentation  of  the  inferior  surface.  Five  scutes  are  represented  in  the  bone.  There 
is  a  long  median  scute  which  narrows  forward,  as  well  as  backward.  It  seems  probable  that 
anteriorly  it  did  not  extend  beyond  the  bone.  This  scute  may  be  the  intergular  which  was 
crowded  backward  by  the  gulars  as  in  Chelodina  novceguince  (Boulenger,  Cat.  Chelonians. 
pi.  vi),  or  it  is  possibly  an  interhumeral  or  an  interpectoral.  Attention  is  called  to  Cope's 
Polythorax  and  Lydekker's  Archceochelys. 

On  each  side  of  the  scute  just  described  is  another  which  may  be  either  an  mtergular  or  a 
gular.     Behind  this  is  a  large  scute  which  is  assumed  to  be  the  humeral. 


I02  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

The  surface  of  the  bone  is  covered  with  rounded  elevations  which  resemble  small  bird  shot. 
There  are  about  eight  in  a  line  lo  mm.  long.  The  basis  of  each  elevation  is  often  of  less 
diameter  than  the  body  of  it.  Many  of  them  are  broken  off  near  the  surface  of  the  bone, 
leaving  circular  scars.  Along  the  edges  of  the  bone  which  joined  the  hyoplastra  there  is  a 
narrow  border  nearly  free  from  the  pustules. 

This  turtle  differed  from  Polythorax  missuriensis  in  the  character  of  the  ornamentation, 
this  consisting  in  the  latter  species  of  short  raised  lines.  In  that  species,  too,  the  pectoro- 
humeral  sulcus  appears  to  have  been  pushed  well  forward.  In  the  species  here  described 
there  is  no  trace  of  the  presence  of  this  scute. 

Superfamily  PLEURODIRA  Cope. 

Thecophorous  turtles  having  a  carapace  composed  of  costals  and  peripheral  bones  and 
usually  a  series  of  neurals  and  a  plastron  in  which  the  epiplastra  are  in  contact  with  the  hyo- 
plastra. Mesoplastra  present  or  absent.  Intergular  scutes  developt,  the  inframarginals 
wanting.  Temporal  roof  of  the  skull  varying  from  nearly  complete  to  nearly  obsolete.  Ptery- 
goids not  extending  backward  between  the  quadrates  and  the  basisphenoid;  broad,  with  the 
outer  border  uprolled.  Neck  bending  sideways;  not  capable  of  being  withdrawn  between  the 
scapulae.  Ilia  suturally  joined  to  the  eighth  costals;  the  pubes  and  the  ischia,  to  the  xiphi- 
plastra. 

The  living  Pleurodira  are  divided  by  Boulenger  into  2  families,  the  Pelomedusidae  and  the 
Chelydidae.  About  30  species  are  known.  None  of  these  have  had  the  anterior  limbs  trans- 
formed into  flippers,  like  those  of  the  Cheloniidx.  The  geographical  distribution  of  the  living 
species  is  illustrated  by  fig.  15,  on  page  34.  The  earliest  turtles  certainly  known  to  belong  to 
this  superfamily  occur  in  the  Upper  Cretaceous  of  North  America.  Cope  referred  these  to  the 
Pelomedusidae;  but  the  present  writer,  following  Baur,  accepts  for  them  the  family  Bothremy- 
didae.  So  far  as  is  known,  no  species  of  the  superfamily  lived  in  North  America  after  the  end 
of  the  Upper  Cretaceous. 

FamUy  BOTHREMYDID.ffi;  Baur. 

Extinct  pleurodire  turtles  having  the  skull  probably  extensively  rooft  over  in  the  temporal 
region.  Vomer  present.  Triturating  surfaces  of  the  jaws,  upper  and  lower,  broad  and  deeply 
excavated.    Shell  as  in  the  Pelomedusidae,  with  small  mesoplastra. 

Baur  was  the  author  who  proposed  this  family,  making  it  include  Bothremy  s  and  Taphro- 
sphys.  Cope  had  arranged  these  genera  under  the  Podocnemididae.  To  the  present  writer 
it  appears  that  the  presence  of  a  vomer,  but  still  more  the  extraordinary  excavations  found 
in  the  jaws,  upper  and  lower,  are  sufficient  to  set  off  Bothremys  as  a  member  of  a  distinct  family. 
With  it  must  go  for  the  present  Taphrosphys. 

Key  to  the  Genera. 
A.  Known  from  skull  only: 

Each  side  of  jaws,  upper  and  lower,  with  a  deep  pit Bothremys 

A  A.   Known  from  shell  only: 

1.  Nuchal  bone  not  shortened;  free  borders  of  peripherals  acute Taphrosphys 

2.  Nuchal  short  and  broad;    free  borders  of  peripheral  obtuse Amhlypeza 

3.  Only  the  xiphiplastron  known;  the  ischiadic  scar  extending  to  the  midline Natadochelys 

Genus  BOTHREMYS  Leidy. 

Vomer  well  developt,  not  separating  the  palatines.  Choanae  behind  the  centers  of  the 
orbits.  The  nasal  passages  underfloored  by  the  surrounding  bones.  Crushing  surfaces  of  jaws 
broad  and  occupying  portions  of  the  maxilla  and  of  the  palatines;  the  excavation  contracting 
to  a  pit  in  each.     Lower  jaw  with  the  dentaries  co-ossified.     Shell  unknown. 

Type:    Bothremys  cookt  Leidy. 

It  has  been  suspected  that  the  skull  represented  by  the  type  of  Bothrem\s  is  that  of  some 
species  of  Taphrosphys,  all  the  species  of  which  are  known  only  from  shells.  This  is  entirely 
possible,  but  nothing  is  to  be  gained  at  present  by  reducing  Taphrosphys  to  a  synonym  of 
Bothremys. 


BOTHREMYDID^. 

Bothremys  cooki   Leidy. 
Plate  23,  figs.  I,  3;    text-figs.  96,  97. 


103 


Bothremys  cookt,  Leidy,  Smitlison.  Contrib.  Knovvl.,  xiv,  art.  vi,  1865,  pp.  no,  120,  plate  xviii,  figs. 
4-8.— Cope,  Cook'.s  Geol.  New  Jersey,  1868  (1869),  p.  735;  Amer.  Naturalist,  iii,  1869,  p.  89; 
Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1870,  p.  157;  Vert.  Cret.  Form.  West,  1875,  p.  263.— Maack, 
Palaeontograph.,  .xviii,  1869,  p.  280.— Baur,  Ann.  and  Mag.  Nat.  Hist.  (6),  iv,  1889,  p.  38.— Hay, 
Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  438. 

The  skull  which  has  furnisht  all  that  we  know  of  this  species  is  a  most  extraordinary  one. 
It  was  found  in  the  lower  bed  of  greensand,  belonging  to  the  upper  Cretaceous,  near  Barnes- 
boro,  Gloucester  County,  New  Jersey,  and  is  now  in  the  geological  collection  of  Rutger's 
College,  New  Brunswick,  New  Jersey,  where  the  writer  has  been  permitted  to  examine  it.  It 
was  fully  described  and  figured  by  Leidy  in  his  original  description.  His  figures  are  stated 
to  be  of  the  size  of  nature,  but  they  are  really  somewhat  reduced.  Plate  23,  figs.  2,  3,  of  the 
present  work  is  reproduced  from  drawings  belonging  to  the  U.  S.  Geological  Survey.  These 
were  prepared  in  1888  for  Dr.  George  Baur,  who  was  then  preparing  to  monograph  the  fossil 
turtles.  The  one  showing  the  lower  surface  of  the  skull  differs  from  that  of  Dr.  Leidy  in 
indicating  the  positions  of  the  sutures.  It  will  be  observed  that  in  this  drawing  the  missing 
quadrate  regions  are  restored  in  outline. 

The  skull,  from  the  tip  of  the  snout  to  the  occipital  condyle,  had  originally  a  length  of 
clo,se  to  70  mm.    The  width  at  the  hinder  end  of  the  maxillae  is  70  mm.    From  the  latter  point 


Figs.  96  and  97. — Bothremys  cooki.     Skull  of  type.      Xjj. 
96.  .Seen  from  above.  97.  Seen  from  right  side. 

the  outline  of  the  skull  rounds  rapidly  to  near  the  end  of  the  snout.  Just  before  this  is  reacht 
the  curves  change  somewhat,  so  that  the  snout  is  slightly  prolonged.  The  skull  is  flat  above 
(text-figs.  96,  97)  there  being  a  slight  descent  from  the  orbits  forward.  The  interorbital 
space  is  17  mm.  wide.  The  eyes  lookt  strongly  upward.  Both  diameters  of  the  orbits 
measure  14  mm.  From  the  upper  borders  of  the  orbits  the  sides  of  the  face  sloped  downward 
and  outward  with  a  moderate  curvature.  The  outline  of  the  upper  jaw,  seen  from  the  side, 
is  very  convex.  The  nasals  are  absent.  Whether  or  not  the  temporal  region  was  widely 
rooft  over  is  uncertain,  but  it  is  probable  that  such  was  the  case. 

A  view  of  the  lower  surface  of  the  skull  shows  many  interesting  features.  The  premaxillae 
are  large,  extending  backward  a  distance  of  18  mm.  Behind  these  comes  the  well-developt 
vomer,  which  presents  feeble  palatine  plates,  to  aid  in  underflooring  the  nasal  passages. 
The  length  of  the  vomer  as  seen  from  below  is  15  mm.  It  lacks  much  of  reaching  the 
pterygoids.  The  palatines  meet  the  vomer  in  advance  of  the  choanae.  The  anterior  borders  of 
the  choanae  are  placed  24  mm.  behind  the  tip  of  the  snout.  These  choanx  lie  in  a  vaulted 
excavation,  which,  beginning  on  the  premaxillae  and  expanding  backward,  reaches  to  the  post- 
palatine  foramina,  being  shallow  in  front  of  the  choanae.  The  excavation  is  bounded  on  each 
side  by  a  prominent  tootht  ridge,  the  inner  boundary  of  the  triturating  surface  of  the  jaw. 
The  pterygoids  meet  along  the  midline  a  distance  of  only  7  mm.    As  in  the  Pleurodira  gener- 


I04  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

ally,  the  pterygoids  are  wide,  and  the  outer  border  is  uprolled  in  a  scroll-like  manner.  The 
basisphenoid,  most  of  which  is  present,  is  large,  the  width  being  13  mm. 

The  most  striking  feature  of  the  skull  is  presented  by  the  triturating  surfaces  of  the  upper 
jaws.  On  the  premaxillae  they  are  very  narrow.  Backward  each  expands  rapidly  and  occupies 
most  of  both  the  maxilla  and  the  palatine.  The  greatest  width  is  24  mm.  Each,  instead  of 
being  flat,  is  deeply  excavated.  At  the  suture  between  the  maxilla  and  the  palatine  the  exca- 
vation contracts  into  a  circular  pit  which  rises  in  the  maxilla  to  the  height  of  the  floor  of  the 
orbit.  The  walls  inclosing  this  pit  are  smooth.  The  remainder  of  the  triturating  surface  is 
perforated  by  openings  for  blood-vessels. 

The  lower  jaw  shows  little  else  than  the  co-ossified  dentaries.  These  are  of  very  solid 
construction.  The  jaw  as  a  whole  is  thin  and  pointed  in  front,  but  the  coronoid  processes  rise 
to  a  height  of  27  mm.  The  symphysis  has  a  length  of  20  mm.  The  triturating  surfaces  are  as 
remarkable  as  those  of  the  upper  jaw.  Each  may  be  described  as  containing  a  deep  pit, 
situated  at  the  hinder  end  of  the  dentary  and  opening  forward  and  upward,  trumpet-like,  on 
the  upper  surface  of  the  dentary.  The  trumpet-shaped  mouth  extends  forward  to  near  the  tip 
of  the  jaw.  It  is  bounded  outwardly  by  the  cutting-edge  of  the  jaw;  inwardly  by  a  ridge,  which 
rising  at  the  tip  of  the  jaw,  runs  backward  and  upward,  increasing  in  height  to  the  coronoid 
process,  along  the  inner  border  of  the  ramus. 

The  purpose  of  the  pit-like  excavations  in  the  jaws,  upper  and  lower,  is  problematical. 
In  speaking  of  the  pit  in  the  upper  jaw  Leidy  said  that  it  did  not  appear  like  an  alveolus  for  a 
tooth,  but  that  it  may  have  accommodated  a  corneous  tooth-like  process  springing  from  the 
corresponding  hollow  of  the  lower  jaw.  Baur  thought  that  the  pits  lookt  much  like  the  alveoli 
of  large  tusk-like  teeth. 

It  does  not  appear  probable  that  there  were  any  teeth  in  this  turtle.  It  seems  far  more 
probable  that  both  jaws  were  covered  with  plates  of  horn,  as  are  those  of  all  other  known 
turtles.  The  whole  construction  of  the  skull  of  Bothremys  indicates  that  it  was  accustomed  to 
crush  hard  objects  as  food.  Probably  these  objects  were  of  sucK  a  nature  that  economy  of 
force  demanded  that  they  should  be  brought  to  a  particular  spot  on  the  jaw  for  crushing.  To 
provide  for  the  rapid  reproduction  of  the  horn  beneath  these  areas  for  crushing,  these  pits 
became  developt  in  a  way  analogous  to  the  human  "nail-bed." 

Genus  TAPHROSPHYS  Cope. 
Prochonias  CoPE. 

A  genus  of  pleurodirid  turtles  known  only  from  the  shell.  Carapace  with  y  neurals,  the 
costals  of  the  seventh  and  eighth  pairs  meeting  their  fellows  at  the  midline;  a  large  suprapygal; 
and  1 1  pairs  of  peripherals,  the  posterior  thin  and  with  acute  free  borders.  No  nuchal  scute. 
Plastron  with  1 1  bones,  the  mesoplastrals  small  and  well  out  on  the  bridges.  A  single  intergular 
almost  wholly  confined  to  the  entoplastron.  Hinder  lobe  with  large  notch.  Large  pits  in  the 
first  and  the  fifth  costals  for  the  axillary  and  inguinal  buttresses.  Ilium  firmly  articulated  with 
the  carapace  at  the  junction  of  the  seventh  and  eighth  costals.  Ischium  and  pubis  articulated 
to  the  xiphiplastron. 

Type:    Platemys  sulcatus  Leidy. 

In  Cook's  Geology  of  New  Jersey,  1868  (1869),  page  735,  Cope  mentions  the  generic  name 
Taphrosphys  in  connection  with  3  specific  names,  as  follows:  T.  molops,  T.  princeps,  and 
T.  sulcatus.  The  first  two  had  not  yet  been  described,  the  last  was  Leidy's  Platemys  sulcatus. 
In  the  April  (1869)  number  of  the  American  Naturalist,  Cope  again  mentions  the  name 
Taphrosphys,  this  time  in  connection  with  molops  only,  while  to  the  new  genus,  Prochonias, 
were  referred  the  species  P.  sulcatus,  P.  strenuus,  and  P.  princeps.  Of  these  again  none  had 
yet  been  described  except  P.  sulcatus  (Leidy).  The  latter  therefore  is  the  type  both  of 
Taphrosphys  and  Prochonias.  Which  of  these  names  has  precedence  depends  on  which  was 
issued  first  to  the  public,  the  April  number  of  the  American  Naturalist  or  Cook's  Geology  of 
New  Jersey.  Investigations  not  wholly  satisfactory  seem  to  show  that  the  latter  was  first 
publisht,  probably  some  time  about  the  first  of  March,  1869.    This  conclusion  enables  us  to 


BOTHREMYDID^.  IO5 

retain  the  name  to  which  Cope  finally  referred  all  the  species  named  above  and  some  others. 
In  his  monograph  of  1869  and  1870,  he  described  all  his  species  and  made  Prochonias  a 
subgenus  of  7aphrosphys.    Here  T .  molops  was  regarded  as  the  type  of  Taphrosphys. 

All  the  species  known  to  belong  to  this  genus  are  represented  by  fragmentary  individuals, 
but  these  furnish  us  the  means  of  obtaining  a  pretty  clear  idea  pf  the  structure  of  the  carapace 
and  the  plastron.  Nothing  is  known  regarding  the  skull,  unless  it  be  that  the  skull  known  as 
Bothremys  cookt  belongs  to  a  species  generically  identical  with  Taphrosphys.  Of  the  limbs 
extremely  little  is  known.  Evidently  the  genus  belonged  to  the  Pleurodira  and  was  not  far 
removed  from  Podocnemis.  There  were  8  pairs  of  costal  bones,  the  last  two  pairs  meeting  on 
the  midline.  The  nuchal  bone  is  large  and  expanded  behind.  There  were  seven  neurals,  the 
first  large,  the  last  small.  There  were  1 1  pairs  of  peripherals,  a  suprapypal  and  a  pygal.  The 
peripherals  of  the  hinder  part  of  the  carapace  were  thin  and  acute.  Those  of  the  anterior 
portion  of  the  bridge,  the  fourth  and  fifth,  appear  to  have  had  the  free  border  thickened  and 
rounded  or  with  faces  at  right  angles;  while  those  succeeding  them  had  the  free  borders  acute 
and  the  faces,  upper  and  lower,  meeting  at  an  angle  less  than  right. 

On  the  inferior  side  of  the  first  costal  was  a  deep  pit  for  the  reception  of  the  axillary  buttress; 
on  the  fifth  was  another  pit  for  the  inguinal  buttress.  An  extensive  excavation,  partly  in 
the  seventh  costal  and  partly  in  the  eighth,  received  the  upper  end  of  the  ilium.  This  excava- 
tion occupied  more  than  a  half  of  the  length  of  these  costals. 

The  upper  surface  of  the  carapacial  bones  is  markt  by  irregular  grooves,  which  anastomose 
more  or  less  and  divide  it  into  areas  differing  in  size  and  form  in  the  different  species  and  on 
diflFerent  parts  of  the  same  individual.  The  sulci  are  shallow  and  sometimes  obscure.  Evi- 
dently, the  epidermis  was  thin.  There  was  no  nuchal  scute.  The  vertebrals  were  rather 
broad.    The  marginals  did  not  overlap  on  the  costal  bones. 

The  plastron  was  well  developt,  but  the  anterior  lobe  was  short  and  broad,  and  rounded. 
Strong  buttresses  rose  from  the  plastron  to  articulate  with  the  carapace.  On  the  xiphiplastrals 
were  well-developt  articulatory  surfaces  for  union  with  the  ischia  and  the  pubes.  The  posterior 
notch  was  large  and  rounded.  As  stated  by  Cope,  and  as  shown  by  the  borders  of  various 
hyoplastra  and  hypoplastra,  there  were  small  triangular  mesoplastra,  which  occupied  each  a 
position  on  its  bridge.  The  free  borders  of  the  anterior  lobe  were  mostly  obtuse;  those  of  the 
hinder  lobe  were  mostly  acute.  The  inferior  surface  is  sculptured  like  the  carapace;  but 
often  the  markings  are  obscure.  The  scutes  of  the  anterior  lobe  are  not  all  satisfactorily 
determined.  There  was  a  large  intergular  that  occupied  a  considerable  part  of  the  entoplastron. 
Apparently,  as  shown  in  the  figure  of  the  anterior  lobe  of  7".  mo/o /ix  (fig.  116),  this  was  bounded 
in  front  by  a  sulcus  across  the  entoplastron,  thus  permitting  the  gulars  to  meet  each  other  at  the 
midline.  It  is  possible  that  the  intergular  extends  to  the  front  of  the  lobe,  as  represented  in 
fig.  106,  and  that  the  gulars  do  not  join  each  other.  The  humerals  lie  on  the  outer  ends  of  the 
epiplastra,  overlapping  on  the  hyoplastra.  The  arrangement  of  the  other  plastral  scutes  may  be 
seen  from  the  figures.    Those  on  the  bridges  are  not  known. 

//'.  Species  with  shell  having  an  even  surface,  except  that  it  bears  a  network  of  vascular  grooves, 
a'.  Surface  of  shell  usually  with  a  close  network  of  rather  broad  grooves. 

1.  A  large  species  with  bones  of  moderate  thickness;    the  fourth  vertebral  scute 

nearly  a  half  wider  than  long sulcatus 

2.  A  species  of  moderate  size;    second    and   fourth  vertebral    scutes  little  wider 

than  long longinuchus 

3.  A  small  species  with  thin  bones;  second  vertebral  scute  twice  as  wide  as  long; 

the  fourth  probably  as  wide  as  the  second leshanus 

4.  A  large  species  with  thick  bones;   front  of  plastron  broad,  truncated,  or  concave 

on  each  side  of  the  thickened  epiplastral  symphysis strenuus 

5.  A  large  species  with  bones  of  moderate  thickness;    front  of  plastron  rounded; 

the  first  and  third  vertebral  scutes  about  one-half  wider  than  long molops 

(?.  Surface  with  thread-like  grooves  which  form  large  meshes. 

A  large  species  with   thick  bones;    entoplastron   broader  than   long,  its  postero- 
lateral sides  excavated i/ar« 

A"^.  Surface  of  shell  coarsely  sculptured  like  that  of  the  Trionychidae nodosus 


ta5 


FOSSII.    TURTLES    OF    NORTH    AMERICA. 

Taphrosphys   sulcatus  L.eidy. 
Teit-figs.  98-100. 


Pliitemys  sulcatus,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.,  viii,  1856,  p.  303;   Smithson.  Contrib.  Know!., 

XIV,  an.  VI,  1865,  pp.  log,  120,  plate  xix,  fig.  4. — Maack,  Palseontographica,  xviii,  1869,  p.  281. 
Taphrosphys  sulcatus,  CoPE,  Cook's  Geol.  New  Jersey,  t868  (1869),  p.  735;    Ext.  Batrach.,  Reptilia, 

Aves  N.  A.,  1870,  pp.  159,  164,  text-figs.,  45,  45  bis;   Vert.  Cret.  Form.  West,  1875,  p.  264. — Hay, 

Bibliog.  and  Cat.   Foss.  Vert.  N.  A.,   1902,  p.  439. 
Prochonias  sulcatus.  Cope,  Atner.  Naturalist,  iii,  1869,  pp.  89,  90;    Ext.  Batrach.,  etc.,  p.  165,  line  8, 

plate  xi,  fig.  2. 

As  has  occurred  too  often  in  the  history  of  paleontology,  the  present  species  was  based  on 
very  meager  materials.  These  consisted  of  3  peripheral  bones,  regarded  as  the  fifth,  sixth,  and 
seventh,  and  a  xiphiplastral.  Only  the  peripherals  were  figured.  These  were  large,  measuring 
altogether  8  inches  along  the  free  border.  They  came  from  the  Cretaceous  greensand  at  Tinton 
Falls,  Monmouth  County,  New  Jersey,  and  are  preserved  in  the  geological  collection  of  Rutgers 
College,  New  Brunswick,  New  Jersey.  Leidy's  description  of  these  bones  is  very  brief.  Each 
bone  has  two  faces,  an  upper  and  a  lower,  the  lower  broad  and  flat,  the  upper  inclining  toward 
it  at  an  angle  of  nearly  45°,  the  two  meeting  along  an  acute  margin.    The  fifth  is  54  mm.  long  on 


99. 


Figs.  98  and  99. — Taphrosphys  sulcatus.     No.  1468  A.  M.  N.  H. 
98.  Section  of  seventh  peripheral  of  type.     X^.  99.  Rear  of  carapace.     Xj. 

the  free  border;  the  sixth,  60  mm.;  the  seventh,  76  mm.  The  sixth  rises  from  the  free  border  to 
the  costal  border,  69  mm.;  the  seventh,  70  mm.  The  anterior  end  of  the  seventh  is  much  thick- 
ened and  has  afforded  an  articulation  with  the  inguinal  buttress.  In  front  of  this  articulation 
the  bone  is  somewhat  excavated  by  the  sternal  chamber.  The  hinder  end  of  this  peripheral  is 
thin,  not  exceeding  14  mm.  (fig.  98).  The  free  borders  of  all  these  peripherals  are  acute. 
The  superior  surface  is  ornamented  by  a  close  articulation  of  grooves.  Fig.  98  represents  a 
section  along  the  sulcus  between  the  marginal  scutes  that  overlapt  this  bone.  The  piece  of 
xiphiplastron  displayed  the  scar  for  union  with  the  pelvis. 

With  this  species  Cope  identified  a  specimen  which  he  obtained  from  the  upper  greensand 
bed  at  Barnesboro,  Gloucester  County,  New  Jersey.  This  specimen  furnisht  him  the  three 
hinder  pairs  of  costal  plates,  the  suprapygal,  the  pygal,  and  a  number  of  the  hinder  peripherals. 
There  are  present  also  portions  of  two  bridge  peripherals  and  some  fragments  of  other  costals. 
There  appears  to  be  no  reason  for  doubting  the  correctness  of  Cope's  identification.  This 
specimen  (figs.  99,  100)  is  now  in  the  American  Museum  and  has  the  catalog  number  1468. 
It  now  lacks  all  the  peripherals  that  Cope  figured,  except  one.  According  to  his  figure.  Cope 
lackt  the  eleventh  peripheral.  The  one  now  present  was  certainly  in  Cope's  hands,  having 
his  marks  on  it;   and  yet,  after  careful  examination,  that  bone  is  found  to  fit  in  the  place  of  the 


BOTHREMYDID^.  IO7 

light  eleventh  peripheral  and  nowhere  else.  With  it  is  connected  a  portion  of  the  pygal.  The 
proximal  half  of  the  left  sixth  costal  is  now  missing.  On  the  other  hand,  the  distal  end  of  the 
right  seventh  costal  has  been  found  and  included  in  the  figure. 

The  individual  was  a  large  one,  the  length  of  the  carapace  being  estimated  at  650  mm. 
Cope  states  that  his  figure  is  one-third  the  natural  size,  but  in  reality  it  is  in  width  only  a  little 
more  than  twenty-two  hundredths  of  the  original.  As  regards  the  length  of  his  figure,  it  is 
much  foreshortened. 

As  in  the  other  species,  the  costals  of  the  last  two  pairs  (fig.  99)  meet  at  the  midline.  The 
eighth  neural  was  not  developt  and  the  seventh  was  short.  The  sixth  costals  are  66  mm.  wide 
at  their  distal  ends;  the  seventh,  70  mm.,  the  eighth,  54  mm.  The  sixth  is  9  mm.  thick  where 
it  joined  the  neural;  5  mm.  at  the  distal  end. 

The  suprapygal,  described  by  Cope  under  the  name  of  pygal,  is  triangular,  pointed  above, 
83  mm.  long  and  99  mm.  wide  behind.  The  eleventh  peripheral  measures  72  mm.  along  the  free 
border  and  is  65  mm.  high.  The  free  edge  is  acute.  It  is  slightly  thicker  at  the  hinder  end  than 
in  front,  being  10  mm.  posteriorly. 

Fragments  of  two  bridge  peripherals  are  present.  One,  probably  belonging  near  the 
hinder  end  of  the  bridge,  has  the  two  faces  meeting  with  an  angle  of  about  50  degrees  between 


Fig.  100. — Taphrosphys  sulcatus.     Under  side  of  rear  of  carapace.      X^.     No.  1468  A.  M.  N.  H. 

AA,  excavated  area  for  ilium;  x,  sacral  rib. 

them  at,one  end,  probably  the  anterior.  At  the  other  end  the  faces  meet  at  an  angle  of  about 
30  mm.,  the  free  border  being  acute.  The  other  fragment  has  the  two  faces  meeting  at  an  angle 
of  about  90°.    This  bone  probably  belonged  near  the  front  end  of  the  bridge. 

As  Cope  states,  the  sculpture  of  the  upper  surface  of  the  carapace  is  coarsely  reticulate, 
tending  to  enclose  areas  longitudinal  with  the  costals  toward  their  middle  and  distal  portions, 
while  that  of  the  peripherals  is  closer.  The  sulci  are  shallow  and  narrow.  The  fourth  vertebral 
scute  was  about  no  mm.  long  and  154  mm.  wide;  the  fifth  was  no  mm.  long,  162  mm.  wide, 
only  50  mm.  anteriorly.  Its  lateral  extremities  are  sharply  angled.  The  costo-marginal  sulci, 
so  far  as  they  are  represented,  are  confined  to  the  peripherals. 

On  the  inferior  surface  of  the  carapace  (fig.  100)  we  find,  excavated  partly  in  the  seventh, 
partly  in  the  eighth  costals,  a  large  pit,  78  mm.  long  and  28  mm.  wide,  for  the  reception  of  the 
upper  end  of  the  ilium.  The  pit  is  bounded  anteriorly  by  a  sharp  ridge  proceeding  from  the 
rib-head  of  the  seventh  costal.  This  ridge  is  highest  at  the  upper  end,  lowest  in  the  middle. 
Behind,  the  pit  is  bounded  by  a  low  rough  ridge  running  along  the  middle  of  the  eighth  costal. 
Both  the  costals  are  much  thickened  at  the  lower  end  of  the  pit.  The  upper  end  of  the  pit  is 
inclosed  in  front  by  a  low  ridge  derived  from  the  base  of  the  rib-head  of  each  costal;  behind, 
by  a  distinct  squarish  bone,  which  is  to  be  regarded  as  the  tenth  dorsal  rib,  corresponding  to  the 


io8 


KOSSII.    TURTi.ES    OF    NORTH    AMERICA. 


enlarged  extremity  of  the  tenth  dorsal  rib  of  the  Cryptodira.  On  its  hinder  angle  is  a  broken 
process,  apparently  the  base  of  the  rib-head.  The  distal  end  of  this  bone  abutted  squarely 
against  the  ilium.  IJehind  this  squarish  bone  is  an  irregular  and  rough  excavation  in  the 
eighth  costal,  which  seems  to  have  received  another  bone,  probably  the  first  sacral  rib.  Behind 
the  rough  surface  just  mentioned  is  another,  lying  partly  on  the  anterior  border  of  the  suprapy- 
gal;   and  this  may  have  supported  the  second  sacral  rib,  not  yet  lost  in  these  early  Pleurodira. 

On  the  contiguous  ends  of  the  seventh  and  the  eighth  costals,  in  the  midline,  are  j  rough 
articular  surfaces  which  were  in  contact  with  the  neural  arches  of  three  vertebrae.  Cope  speaks 
of  these  as  having  been  in  contact  with  "rudimental  and  inferiorly  placed  vertebral  pieces." 
It  seems  evident  that  the  rib-head  of  the  eighth  costal  was  connected  with  the  most  anterior; 
the  rib-head  of  the  tenth  rib  with  the  second;   while  the  first  sacral  rib-head  joined  the  third. 

The  portion  of  the  xiphiplastron  present  shows  this  part  of  the  shell  to  have  been  thinner 
than  in  T.  molops.  The  thickness  at  the  hypoxiphiplastral  suture  is  7  mm.  The  edge  of  the 
bone  at  the  bottom  of  the  posterior  notch  is  present.  This  edge  is  acute,  while  from  it  the  bone 
thickens  to  only  9  mm.  The  scar  for  the  pubis  is  somewhat  elongated,  46  mm.  long  and  9  mm. 
wide;  therefore,  much  narrower  than  in  T.  molops.  On  the  inferior  surface  is  seen  a  distinct 
reticulate  sculpture  of  moderate  closeness. 

No.  1469  of  the  American  Museum,  a  part  of  the  Cope  collection,  is  labeled  by  Cope  as 
having  been  found  at  Barnesboro,  New  Jersey,  in  1869;  but  it  has  not  been  identified  as  any 
one  of  those  mentioned  in  his  monograph  so  often  quoted  here.  The  left  second  costal  bone  is 
39  mm.  wide  at  the  middle  of  the  length  and  8  mm.  thick.  The  third  costal  is  49  mm.  wide  at  the 
middle  of  its  length.  Besides  these  costals,  there  are  present  portions  of  the  three  posterior  of 
the  right  side.  These  agree  with  those  of  No.  1468  described  above.  Attacht  to  the  sixth 
costal  is  the  sixth  neural.  It  is  hexagonal,  35  mm.  long,  36  mm.  wide,  and  8  mm.  thick.  The 
epidermal  scute  areas  also  are  like  those  of  number  1468.  The  lateral  apex  of  the  second 
vertebral  is  67  mm.  from  the  neural  border  of  the  costal.  Most  of  the  right  hypoplastron  is 
preserved.  The  length  at  the  midline  is  about  105  mm.;  the  width  at  the  abdomino-femoral 
sulcus  130  mm.;  along  the  hyohypoplastral  suture,  100  mm.  The  bone  is  8  mm.  thick  at  the 
anterior  inner  angle;  6  mm.  at  the  hypoxiphiplastral  suture. 

This  species  differs  from  T .  longtnuchiis  in  having  the  suprapygal  wider  than  long  and  in 
having  the  fourth  vertebral  scute  relatively  much  wider. 

Taphrosphys  longinuchus  Cope. 

Test-figs.  lOl,  102. 

Taphrosphys  (Proihonins)  Inngimichus,  CoPE,  Ext.  I'atrach.,  Reptilia,  Aves  N.  A.,  1870,  p.  159. 
Taphrosphys  longinuchus.  Cope,  op.  cit.,  p.  162;  Vert.  Cret.  Form.  West,  1875,  p.  263. — Hay,  Bibliog. 
and  Cat.  Foss.  Vert.  N.  A.,  iqo2,  p.  +58. 

Cope  stated  in  his  description  of  this  turtle  that  it  had  been  obtained  from  the  excavations 
of  David  Haines,  New  Jersey.  The  label  accompanying  the  specimen,  now  number  1 1^5  of  the 
American  Museum  of  Natural  History,  informs  us  that  the  locality  was  Medford,  which  is  in 

Burlington  County.  The  level  is  stated  by  Cope  in  his  Vertebrata 
of  the  Cretaceous  Formations,  page  263,  as  being  "Greensand 
No.  5,"  which  would  be  the  upper  bed  of  Cretaceous  greensand. 
The  type  specimen  furnishes  a  large  portion  of  the  carapace 
and  of  the  plastron,  but  it  was  much  fractured.  Fig.  101  repre- 
sents the  restored  carapace;  fig.  102  the  restored  plastron.  A  con- 
siderable number  of  other  fragments  remain,  but  can  not  be  fitted 
to  their  places. 

The  species  was  one  of  moderate  size  and  one  whose  shell 
was  of  rather  light  construction.  The  length  of  the  carapace  (fig. 
101)  was  close  to  415  mm.;  the  width  about  390  mm.  The 
form  was  deprest  and  convex  in  all  directions.  Only  the  eighth  peripheral  shows  any  tendency 
toward  upward  flaring.  Only  3  neurals  have  been  preserved — the  fourth,  fifth,  and  seventh. 
The  forms  of  most  of  the  others  are  indicated  by  the  proximal  ends  of  the  contiguous  costals. 
The  dimensions,  so  far  as  determinable,  are  given  in  the  accompanying  table. 


Neural. 

Length. 

Width. 

48 

34 

35 

35 

16 

3» 

22 

26 

22 

7 

21 

20 

BOTHREMYDID^. 


109 


The  borders  of  the  fourth  and  fifth  neurals  are  8  mm.  thick.  On  the  under  side  of  each 
is  attacht  the  neural  arch  of  the  corresponding  vertebra.  The  eighth  neural  was  not  developt 
and  the  costals  of  the  seventh  and  eighth  pairs  met  at  the  midline.  The  ninth  and  tenth  dorsal 
vertebrae  and  the  first  sacral  appear  to  have  had  their  arches  articulated  with  the  inferior 
surface  of  the  seventh  and  eighth  costals  at  their  junction.  The  accompanying  table  gives  the 
dimensions  of  the  three  posterior  neurals. 

The  nuchal  bone  is  urn-shaped,  90  mm.  long,  43  mm.  wide  in  front,  86  mm.  across  the 
widest  part,  and  10  mm.  thick.    Its  free  border  is  acute.    The  first  peripheral  measures  58  mm. 

along  its  free  border;  the  second,  53  mm.  The  first  appears  to 
have  been  about  60  mm.  high,  measured  at  the  suture  with  the 
second.  The  free  border  of  these  two  peripherals  is  subacute. 
The  greatest  thickness  of  the  second,  at  the  distal  end,  is  12  mm. 
On  the  right  side  most  of  the  peripherals  are  wanting  from  the 
second  to  the  eighth  (exclusive  of  both);  all  are  missing  behind  the 
second  on  the  left  side,  except  one,  probably  the  sixth.  The  upper 
and  lower  faces  of  this  sixth  meet  at  the  acute  free  border  at  an 
angle  of  about  45°.  This  border  is  45  mm.  long  and  from  this  the  bone  rises  56  mm.  to  the 
costals.  In  the  restoration  (fig.  loi),  this  bone  has  been  omitted  from  its  supposed  place. 
The  lower  face  of  the  bone,  that  proceeding  to  the  plastron,  is  mostly  missing. 


Neural. 

Length . 

Height.    1 
67 

8 

66 

9 

57 

58 

10 

5° 

49 

Fig.  \o\.^Taphrosphys  longinuchus.     Carapace  of  the  type.      Xj.     The  stippled  areas 

represent  the  known  bones. 

All  of  the  peripherals  have  acute  free  borders.  Of  the  eighth,  that  portion  to  which  the 
inguinal  buttress  was  attacht  is  broken  away.  From  the  free  border  each  of  these  bones 
thickens  on  the  under  side  to  half  its  height,  then  becomes  gradually  thinner. 

The  suprapygal  is  triangular,  62  mm.  long  and  60  mm.  wide  posteriorly.  Evidently  it 
articulated  on  each  side  with  the  eleventh  peripheral  and  medially  with  the  pygal. 


no 


FOSSIL    TURTLES    OK    NORTH    AMERICA. 


VertebraL 

Length. 

Width. 

, 

75 

8o 

2 

75 

77 

3 

75 

9° 

4 

75 

86 

s 

no 

The  fore-and-aft  width  of  the  first  costal  is  64  mm.  at  the  proximal  end;  its  greatest  width 
was  about  90  mm.  Its  length  is  estimated  at  120  mm.  On  the  lower  side,  at  the  distal  end,  is  a 
deep  triangular  excavation,  40  mm.  long,  for  the  axillary  buttress.  From  it  a  broad  ridge 
ascends  to  the  rib-head  of  the  costal.  In  front  of  the  ridge,  along  its  proximal  third  or  more, 
is  another  ridge,  sharper  and  more  prominent,  representing  the  first  rib. 

The  fifth  costal  is  6  mm.  thick  at  its  distal  end.    On  the  under  surface  of  the  distal  end  is  an 

excavation  for  the  inguinal  buttress,  a  groove  ascending  about  60  mm.  above  the  peripheral 

border  and  6  mm.  wide.    It  is  deepest  at  the  upper  end,  becoming  very  shallow  at  the  lower  end. 

The  seventh  and  the  eighth  costals  are  modified  for  close  articulation  with  the  ilium.    On 

the  seventh  the  thickening  produced  by  the  rib  proper  lies  near  the  hinder  border  of  the  bone. 

The  hinder  part  of  the  thickening  is  excavated  somewhat,  espe- 
cially near  the  proximal  end  of  the  costal,  to  form  a  broad  groove 
for  the  ilium.  The  proximal  end  of  the  groove  is  closed  partly 
by  the  ridge  proceeding  from  the  rib-head  of  the  eighth  costal  and 
partly  by  a  subcubic  bone,  which  appears  to  be  the  tenth  rib. 
This  lies  in  a  depression  of  the  eighth  costal.  The  iliac  groove 
is  18  mm.  wide  at  its  upper  end;  and  here  its  bounding  walls  are 
most  prominent.  Behind  the  ridge  limiting  the  groove  posteri- 
-  -  Qj.jy  jj  afiother  groove,  shallower  and  roughly  excavated,  which 
appears  to  have  lodged  a  bone,  probably  the  first  sacral  rib. 

The  surface  of  the  carapace  is  even,  but  it  is  sculptured  everywhere  by  a  network  of 
shallow  grooves.    On  the  costals  the  network  is  the  coarsest,  the  grooves  lying  from  2  mm.  to 

5  mm.  apart  and  mostly  directed  parallel 
with  the  length  of  the  costal.  On  the 
neurals  and  peripherals  the  network  is 
much  closer. 

The  sulci  of  the  carapace  are  broad 
and  shallow.  There  is  no  nuchal  scute, 
the  first  marginals  joining  at  the  midline  a 
distance  of  44  mm.  The  length  of  the  sul- 
cus between  the  first  and  the  second  margi- 
nals is  44  mm.;  that  between  the  second 
and  the  third,  23  mm.  The  sulcus  between 
the  eighth  and  ninth  marginals,  on  the 
eighth  peripheral,  is  37  mm.  long;  the  next 
one,  31  mm.;   the  next,  27  mm. 

The  vertebral  scutes  of  this  species  are 
much  narrower  than  those  of  T.  leslianus, 
as  shown  by  the  table  above. 

The  sulcus  between  the  fifth  vertebral 
and  the  hindermost  marginals  falls  behind 
the  suprapygal. 

The  exact  length  of  the  plastron  (fig. 
102)  can  not  be  determined,  the  connection 
between  the  epiplastron  and  the  hyoplas- 
trals  not  being  present.  The  length  was, 
however,  not  far  from  340  mm.  The  notch 
in  the  rear  of  the  plastron  was  about  30 
mm.  deep,  so  that  the   length    along  the 


KiG.  102. — Taphrosphys  longmuchus.  Plastron  of 
type.  Xj.  Known  portions  represented  by 
stippled  areas. 


midline  was  about  310  mm.  The  epiplastrals  are  relatively  small,  especially  when  compared 
with  those  of  Hydromedusa.  The  hinder  end  of  each  is  broken  off,  but  each  was  probably 
about  70  mm.  long.  The  width  was  about  33  mm.,  while  the  greatest  thickness  of  the  outer 
end  is  7  mm.  The  free  border  is  acute  at  the  midline,  becoming  subacute  distally.  Cope 
describes,  under  the  name  of  mesosternal,  a  portion  of  the  entoplastron,  but  this  is  now  lost. 
He  did  not  give  the  dimensions.  He  states  that  the  extremities  are  acute-angled  and  that 
the  bone  was  even  more  transverse  than  it  is  in  T.  molops. 


bothremyuida;.  fi^i' 

At  the  midline  the  hyoplastra  are  77  mm.  long.  The  usual  thickness  of  the  bones  is  6  mm. 
Laterally,  each  rises  into  a  rather  broad,  but  thin,  axillary  buttress.  The  bridge  was  probably 
about  125  mm.  long. 

The  hypoplastrals  are  87  mm.  long  at  the  midlin  .  The  bridge  portions  of  the  bones  are 
mostly  missing.    There  is  no  trace  of  the  mesoplastrals,  tho  these  doubtless  were  present. 

The  xiphiplastrals  extend  82  mm.  along  the  midline.  The  notch  in  the  rear  is  90  mm. 
wide.  The  borders  of  the  hinder  lobe  are  thin  and  acute.  On  the  upper  surface  of  the  xiphi- 
plastrals are  the  articular  scars  for  the  pubes  and  the  ischia.  The  scars  for  the  latter  are 
mammiform,  17  mm.  long  and  u  mm.  wide,  and  are  sharply  ridged  and  cleft.  The  pubic 
scars  are  somewhat  elevated,  40  mm.  long,  9  mm.  wide,  and  rough. 

The  arrangement  of  the  scutes  of  the  anterior  lobe  can  not  be  wholly  determined.  On  the 
epiplastra  appear  a  pair  possibly  coalesct  at  the  midline,  the  gulars.  There  was  probably  an 
intergular  on  the  entoplastron.  The  sulci  that  separated  the  humerals  from  the  pectorals  is  not 
seen.  The  latter  scutes  crost  the  plastron  about  18  mm.  in  front  of  the  hyohypoplastral  suture. 
The  abdominals  are  40  mm.  wide  at  the  midline;   the  femorals,  90  mm.;   the  anals,  60  mm. 

Cope  described  limb  bones  which  he  regarded  as  two  humeri  and  a  small  part  of  the  prox- 
imal end  of  femur,  but  it  is  quite  certain  that  what  he  called  humeri  are  femora.  The  right 
femur  lacks  the  fibular  process  and  the  distal  end.  Of  the  left  femur  there  is  the  distal  end. 
These  bones  agree  closely  with  those  of  Hydromedusa,  except  that  the  tibial  process  extends 
down  farther  on  the  shaft.  Cope  estimates  from  these  bones  that  the  length  was  97  mm.  It 
was  probably  10  mm.  shorter.  What  seems  to  be  the  head  of  a  humerus  is  too  imperfect  for 
definite  conclusions. 


Fig.  103. — Taphrosphysleslianus.     Anterior  half  of  carapace  of  type.      Xj.     Known  bones 

shown  by  stippled  areas. 

Taphrosphys  leslianus  Cope. 

Text-figs.  105-106. 

Taphrosphysleslianus,  CoPE,  Ext.  Batrach.,  Reptilia,  AvesN.  A.,  1870,  pp.  159,  l66;   Vert.  Cret.  Korm. 

West,  1875,  p.  264.— Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  438. 
Prochonias  leslianus,  CoPE,  Ext.  Batrach.,  etc.,  p.  165,  line  14. 

The  present  species  is,  up  to  this  time,  known  from  only  a  single  specimen.  Cope's  type. 
No.  1467,  of  the  American  Museum  of  Natural  History.  This  specimen  has  not,  until  this 
time,  been  figured.  In  his  description  of  the  specimen  Cope  did  not  state  the  locality  or  the 
level  from  which  it  had  been  derived;  but  his  label  accompanying  the  specimen  informs  us  that 
it  was  found  at  Hornersville,  New  Jersey.  This  is  in  Monmouth  County.  In  his  Cretaceous 
Vertebrata,  page  264,  he  informs  us  that  it  belongs  to  "Greensand  No.  5;"  so  called  because 
he  regarded  the  uppermost  bed  of  Cretaceous  greensand  as  representing  the  Fox  Hills  group. 

The  type  specimen  consists  of  the  left  side  of  the  nuchal,  the  first  and  second  left  periph- 
erals, a  posterior  peripheral,  a  part  of  both  costals  of  the  first  pair,  the  whole  of  the  thud 


112 


FOSSII,   TURTLES    OK    NORTH    AMERICA. 


costal  of  the  left  side,  parts  of  the  second  and  the  fourth  left  costals,  the  distal  end  of  the  fifth 
right  costal,  the  entoplastron,  the  left  hypoplastron,  and  a  portion  of  the  right  xiphiplastron. 

The  species  was  one  of  relatively  small  size,  with  a  deprest  carapace  (fig.  103),  probably 
about  260  mm.  long.  The  carapace  is  thin,  the  first  costal  being  6  mm.  thick  at  the  center; 
the  fourth  at  its  sutural  border,  5  mm.  thick.  The  first  neural  has  a  length  of  35  mm.  and  a 
width  of  18  mm.;  the  second,  a  length  of  20  mm.  and  a  width  of  24  mm.  The  next  two  were 
somewhat  longer.  The  broader  end  of  each  was  in  front,  as  in  the  genus  generally.  The 
nuchal  bone  was  relatively  long  and  narrow,  the  length  being  close  to  67  mm.,  the  width  close  to 
60  mm.  The  width  in  front  was  only  28  mm.  This  bone  resembles  closely  that  of  Hydrome- 
dusa.     Its  anterior  border  was  thin  and  acute. 

The  first  costal  bone  is  62  mm.  wide  fore  and  aft,  and  75  mm.  long  and  6  mm.  thick  posteri- 
orly. On  its  inferior  surface  at  the  distal  end  is  an  excavation  for  the  axillary  buttress.  This 
rises  30  mm.  above  the  lower  end  of  the  bone  and  is  9  mm.  wide.  The  third  costal  is  21  mm. 
wide  and  105  mm.  long.  The  right  fifth  is  33  mm.  wide  distally.  On  its  inner  surface,  near 
the  distal  end,  is  an  excavation  for  the  inguinal  buttress,  33  mm.  long  and  7  mm.  wide.  The 
first  and  the  second,  and  probably  all  the  other  costals  articulated  with  the  peripheral  bones. 
The  rib-heads  were  moderately  developt. 


Figs.  104  and  105. — Taphrosphys  hsUanus.     Portions  of  type. 

104.  Entoplastron.     X§.  105.  Portions  of  reir  of  plastron.   X^. 

Known  bones  shown  by  stippling. 

The  first  peripheral  has  a  length  of  42  mm.  along  the  free  border,  and  rises  from  this  a 
distance  of  49  mm.  The  second  is  37  mm.  along  the  free  border  and  33  mm.  high.  The  free 
border  of  the  first  is  acute;  that  of  the  second,  subacute.  The  upper  surface  of  each  is  convex 
in  all  directions.  The  thickness  of  the  hinder  end  of  the  second  peripheral  is  8  mm.  A  posterior 
peripheral  is  35  mm.  long.  It  flares  upward  toward  the  free  border.  The  latter  is  acute. 
The  surface  of  the  carapace  is  smooth,  but  there  appears  ever3rwhere  a  rather  indistinct 
reticulation  of  grooves,  which  are  narrower  than  the  inclosed  spaces. 

The  sulci  are  shallow  but  not  diflicult  to  trace.     There  is  no  nuchal  scute.     The  first 
marginals  join  at  the  midline  a  distance  of  about  30  mm.    The  sulcus  between  the  first  and 

second  marginals  is  38  mm.  long;  that  between  the  second  and 
the  third,  22  mm.  Posteriorly  the  marginals  rose  rather  high  on 
the  peripherals.  The  intermarginal  sulci  are  nearer  the  anterior 
ends  of  the  peripherals.  The  vertebral  scutes  have  the  dimensions 
given  in  the  accompanying  table. 

The  entoplastron  (fig.  104)  is  diamond-shaped,  with  rounded 
angles.     The  length  is  30  mm.;   the  width,  31  mm.;    the  thick- 
ness, 3.5  mm.     No  other  part  of  the  anterior  lobe  is  present. 
A  considerable  portion  of  the  left  hypoplastron  is  preserved  (fig.  105).     The  hyoplastral 
border  makes  an  angle  of  about  60°  with  the  free  border  of  the  hinder  lobe  and  a  right  angle 
with  the  median  border,  so  far  as  the  latter  is  represented.    Cope  appeared  to  think  that  the 


Vertebral. 

Length . 

i 

Width. 

2 
3 

48 

64 

•'5 

bothremydida:. 


uj 


/■ 


mesoplastron  continued  to  the  midline.  This  is  not  probable.  The  mesoplastron  evidently 
extended  inward  only  to  the  change  in  the  direction  of  the  anterior  border  of  the  hypoplastron; 
that  is  about  one-third  the  distance  from  the  peripherals  to  the  midline. 

The  inguinal  buttress  is  prominent,  but  thin.  The  hinder  lobe  narrowed  rapidly,  so  that, 
while  about  150  mm.  wide  at  the  inguinal  notch,  it  was  only  about  120  mm.  at  the  hypo- 
xiphiplastral  suture.  The  thickness  of  the  bone  behind  the  inguinal  notch  is  4  mm.  Only  a 
fragment  of  the  right  xiphiplastral  is  preserved.  It  extends  from  the  midline  to  the  free  border 
along  the  anterior  end;  backward  to  behind  the  scar  for  the  pubis.  The  free  border  was  acute. 
The  ischiadic  scar  is  elevated,  28  mm.  long,  and  1 1  mm.  wide. 

The  surface  of  the  plastral  bones  shows  no  sculpture.  On  the  entoplastron  may  be  traced 
sulci  bounding  laterally  and  posteriorly  the  intergular  scute.  Its  anterior  boundary  can  not  be 
made  out.  On  the  xiphiplastron  is  seen  the  femoro-anal  sulcus,  18  mm.  behind  the  front  border 
at  the  midline;   26  mm.  toward  the  free  border. 

No.  1471  of  the  American  Museum  of  Natural  History  is  referred  provisionally  to  this 
species.  The  specimen  was  one  of  the  Cope  collection  and  accompanied  another  specimen 
that  was  labeled  as  coming  from  Barnesboro,  Gloucester  County,  New  Jersey.  Without 
doubt  it  came  from  the  Upper  Cretaceous.  It  consists  of  the  right  epiplastron  (fig.  106),  a  part 
of  the  left  epiplastron,  a  portion  of  the  left  hyoplastron,  a  part  of  the  left  hypoplastron,  and  a 
few  other  fragments.  The  individual  was  nearly  as  large  as  the  type  of  T.  molops,  and  there- 
fore considerably  larger  than  the  type  of  T .  hslianus.  The  plastral  bones  are  thin,  the  thick- 
ness of  the  hinder  end  of  the  epiplastron  being  8  mm.,  that  of  the  hyoplastral  border  near  the 
axilla,  9  mm.  They  are  thinner  than  most  of  the  corresponding  bones  of  the  type  of  T.  loti- 
ginuchus,  a  considerably  smaller  individual. 

The  epiplastron  measures,  in  a  straight  line  from  the  epiplastral  symphysis  to  the  hyo- 
epiplastral  suture,  86  mm.    The  length  of  the  symphysis  is  20  mm.;  the  greatest  width  of  the 

epiplastron  is  37  mm.    An  abrupt  ridge 
\        I  I     j^\  at  the  symphysis  increases  the  thick- 

ness to  10  mm.  The  free  border  is 
subacute  for  a  short  distance  on  each 
side  of  the  midline;  elsewhere,  obtuse. 
Most  of  the  free  border  of  the  hyo- 
plastron is  obtuse. 

The  entoplastron  had  a  width  of 
close  to  70  mm.;  it  was  probably  not 
over  60  mm.  long.  The  thickness  of 
the  hyoplastron  immediately  behind  the 
entoplastron  is  6  mm. 

The  fragment  of  hypoplastron  ex- 
tends along  the  midline  90  mm.  This 
suture  was  very  jagged.  At  a  ridge 
on  the  upper  surface  near  the  front  of  this  bone  the  thickness  amounts  to  12  mm.  Posteriorly 
it  be:omes  reduced  to  5  mm.  Of  the  hyohypoplastral  suture  there  is  present  no  mm. 
The  hinder  bone  was  somewhat  overlapt  by  the  hyoplastron. 

The  inferior  surface  of  these  bones  shows  little  sculpture.  Only  faint  traces  are  seen  of  the 
network  of  grooves  present  in  most  of  the  species  of  the  genus.  On  the  hypoplastron  are  seen 
some  faint  grooves  running  at  right  angles  with  the  median  longitudinal  suture. 

About  certain  of  the  anterior  sulci  there  is  some  doubt.  Those  which  appear  to  be  present 
are  represented  in  fig.  106.  There  is  some  doubt  about  the  first  sulcus  represented  on  each 
side  of  the  midline.  Probably  there  ought  to  be  a  sulcus  drawn  across  the  anterior  end  of  the 
entoplastron,  but  since  this  bone  is  missing  we  can  not  determine  this.  There  is  certainly  a 
gulo-humeral  sulcus  across  the  epiplastron,  and  a  humero-pectoral  across  the  front  ends  of  the 
hyoplastrals.  The  abdomino-femoral  sulcus  crost  the  hypoplastron  39  mm.  behind  the 
hyohypoplastral  suture.  Mainly  on  account  of  the  thinness  of  these  bones  they  are  referred 
to  T.  leslianus;  for  there  are  no  parts  common  to  this  specimen  and  the  type.  The  parts  of 
the  hypoplastra  present  hardly  coincide.    No.  1471  was  considerably  larger. 


Fig.  106. — Taphrosphys  leslianus.  Anterior  lobe  of 
plastron.  Xj. '  No.  1471  A.  M.  N.  H.  Known 
bones  shown  by  stippling. 


8 


114  FOSSIL   TURTLES    OF   NORTH    AMERICA. 

Taphrosphys   strenuus   Cope. 
Figs.  107-11 I, 

Taphrosphys  princeps.  Cope,  Cook's  Gcol.  New  Jersey,  1868  (1869),  p.  7^5  (name  only). 

Taphrosphys  strenuus.  Cope,  Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1870,  pp.  157,  166-B;  Vert.  Cret. 
Form.  West,  1875,  p.  264;  Kerr's  Report  Geol.  Surv.  N.  C,  1875,  Append.  B,  p.  ;?4;  Amer.  Nat- 
uralist, XII,  1878,  p.  128. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  439. 

Prochonias  strenuus.  Cope,  Amer.  Naturalist,  iii,  1869,  pp.  89,  90;    Ext.  Batrach.,  etc.,  pp.  159,  167. 

Prochonias  princeps,  CoPE,  Amer.  Naturalist,  in,  1869,  p.  89;   Ext.  Batrach.,  etc.,  pp.  160,  167,  line  44. 

Altho  the  present  species  had  been  previously  mentioned,  the  earliest  description  of  it  is 
found  in  Cope's  monograph  on  the  Extinct  Batrachia,  Reptilia,  and  Aves  of  North  America, 
page  166-B,  issued  in  April,  1870.  Here  Cope  states  that  he  had  in  his  possession  3  specimens. 
Only  one  of  these,  the  second  mentioned  by  him,  has  been  found  in  his  collection  in  the 
American  Museum  of  Natural  History.  This  has  the  number  1126.  It  appears  that  the  first 
specimen  mentioned  by  him  had  been  intended  as  the  type  of  the  species,  while  the  one  now 
numbered  11 26  had  been  intended  as  the  type  of  his  species  princeps.  Before  the  description 
of  the  latter  was  printed  it  appears  that  he  concluded  to  abandon  it.  Cope's  description  of 
T.  strenuus  bears  evidences  of  imperfect  revision.  The  second  specimen,  number  1 126,  is 
labeled  by  Cope  as  having  been  obtained  from  the  West  Jersey  Marl  Company's  pits  at  Barnes- 
boro,  Gloucester  County,  New  Jersey.  The  level  is  the  Upper  Cretaceous.  The  remains 
are  much  broken,  consisting  of  about  75  pieces;  and  so  many  parts  are  missing  that  it  is 
impossible  to  determine  the  exact  position  of  many  of  those  which  remain.  Of  the  neurals 
none  is  preserved.    A  few  fragments  of  the  costals  remain.      One,   probably   the   fragment 


Fig.  107. — Taphrosphys  strenuus.     Anterior  lobe  of  plastron.     X^.    No.  1 126  A.  M.  N.  H. 
Known  portions  shown  by  stippled  areas. 

whose  width  and  thickness  are  given  by  Cope,  is  91  mm.  long,  57  mm.  wide,  and  10  mm.  thick. 
The  rib  scarcely  shows  on  the  inferior  surface.  The  upper  surface  presents  a  network  ot 
shallow  grooves  at  one  end,  but  at  the  other  the  grooves  inosculate  but  little  and  run  nearly 
parallel  with  the  sutural  borders.  Cope  states  that  the  peripherals  are  rough  from  the  reticu- 
late sculpture.  A  fragment  of  what  is  believed  to  be  an  anterior  peripheral  shows  a  close 
network  of  grooves.     The  greatest  thickness  of  this  bone  is  21  mm.     Its  free  border  is  obtuse. 

Large  portions  of  the  plastron  are  preserved.  The  bones  are  thick  and  heavy.  Pieces 
which  belong  at  the  crossings  of  the  sutures  measure  in  thickness  about  18  mm.,  increasing  in 
places  to  20  mm.  As  in  other  species  of  the  genus,  the  transverse  sutural  faces  are  oblique  to 
the  upper  and  lower  surfaces  of  the  plastron,  so  that  the  hyoplastron  overlapt  somewhat  the 
hypoplastron;  and  the  latter,  the  xiphiplastron.  On  the  inferior  surface  the  network  ot 
grooves  is  coarse.     On  one  fragment  is  seen   a   narrow   and   shallow  sulcus. 

The  anterior  lobe  of  the  plastron  was  broad  and  short  (fig.  107).  The  right  epiplastron  is 
present  and  shows  the  whole  of  its  free  border,  but  some  of  the  entoplastral  border  is  broken 
away.  To  this  is  attacht  a  part  of  the  free  border  of  the  hyoplastron.  The  width  of  the  lobe 
at  the  hyoepiplastral  suture  was  close  to  300  mm.  The  front  of  the  lobe  was  concave  for  a 
considerable  distance  on  each  side  the  midline.  The  fragment  of  hyoplastron  is  18  mm.  thick, 
but  it  thins  to  the  subacute  free  border.  On  the  epiplastron  the  free  border  becomes  obtuse, 
the  thickened  part  of  the  bone  coming  nearer  the  edge  than  on  the  hypoplastron.  At  the 
epiplastral  symphysis  the  bone  rather  suddenly  thickens  to  22  mm. 


BOTHREMYDIDi*. 


"5 


The  entoplastron  must  have  been  unusually  large.  Its  anterior  end  approacht  within 
32  mm.  of  the  anterior  border.  The  anterior  angle  was  slightly  greater  than  100°.  The  sides 
bounding  this  angle  were  approximately  130  mm.  long.  The  width  must  have  been  about 
160  mm.  The  inferior  surface  of  the  epiplastron  displays  an  obscure  reticulation,  but  the 
hypoplastron  is  smooth. 

There  are  present  2  fragments  of  the  right  xiphiplastron.  One  of  these  is  the  hinder  angle 
and  bears  the  ischiadic  articulation;   the  other  shows  the  bottom  of  the  great  notch  at  the  rear 

109.  and   a   part   of  the   median    suture.     These 

fragments  join  and  are   represented   by   fig. 
108.    The  angular  extremity  had  a  very  obtuse 
no.  'ree  border.     A  short  distance  from  the  edge 

the  thickness  is  17  mm.  The  ischiadic  articu- 
~~I  latory  (fig.  108,  E)  surface  is  elevated  and 
about  40  mm.  long  and  24  mm.  wide.  It  is 
now  much  eroded.  In  front  of  this  articula- 
tion the  thickness  is  13  mm.  The  median 
longitudinal  suture  is  coarse  and  jagged.  Fig. 
109  represents  a  section  across  the  hinderouter 
angle  along  the  line  CD  of  fig.  112.  Fig.  no 
is  a  section  along  the  line  AB  of  fig.  108.  The 
posterior  notch  was  about  180  mm.  wide  and 
relatively  shallow.  It  appears  to  differ  much 
from  the  notch  in  other  species  of  the  genus. 
While  the  free  border  of  the  extremity  of 
the  xiphiplastron  is  very  obtuse,  more  anteri- 


p'lGS.    108-III. — Taphrosphys    stretiuus. 

No.  1126  A.  M.N.  H. 


xi 


108.  Right  xiphiplastron,  upper  surface.   <4B,  line  of  section 

represented    by   figure    no;    C£),  line   of   section 
represented  by  figure  109;  £,  ischiadic  articulation. 

109.  Section  along  line   CD   of  figure  108. 
no.  Section  along  line  AB  of  figure  108. 
III.  Section  at  hypoiiphiplastral  suture. 


orly  it  becomes  acute.    Fig.  in  is  a  section  at  the  hypoxiphiplastral  suture. 

Cope  described  a  bone  which  he  regarded  as  the  proximal  end  of  the  femur.  With  little 
or  no  doubt  the  bone  is  the  left  humerus.  It  presents  close  resemblances  to  the  corre- 
sponding bone  of  Chelydra,  the  radial  and  ulnar  processes,  however,  not  being  so  thin  as  in 
the  latter  genus.  Cope  also  described  as  a  coracoid  a  bone  which  certainly  belongs  to  the 
pelvis,  having,  as  Cope  states,  2  sutural  faces  and  I  cotyloid  face. 

Taphrosphys  molops  Cope. 
Figs.  112-120. 

Taphrosphys  molops,  CoPE,  Cook's  Geol.  New  Jersey,  1868  (1869),  p.  735  (name  only);  Anier.  Naturalist, 
III,  1869,  p.  89;  Proc.  Amer.  Philos.  Soc,  xi,  1870,  p.  274;  Ext.  Batrach.,  Reptilia,  Aves  N.  A., 
1870,  pp.  158,  159,  plate  vii,  fig.  16,  text-figs.  43,  44;  Vert.  Cret.  Form.  West,  1875,  p.  263.— Hay, 
Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  438. 

Taphrosphys  molops  var.  enodis.  Cope,  Fxt.  Batrach.,  etc.,  p.  162. 

Prochonias  enodis.  Cope,  Ext.  Batrach.,  etc.,  pp.  158,  160. 

Bothremys  {Taphrosphys)  molops,  Zittei.,  Handbuch   Palaeontologie,   1889,  p.  547. 

Of  this  species  Cope  had  a  number  of  specimens,  none  wholly  complete,  most  of  them, 
very  incomplete.  The  one  which  presented  large  portions  of  the  carapace  and  the  plastron 
had  been  obtained  from  the  upper  bed  of  Cretaceous  greensand,  at  Barnesboro,  Gloucester 
County,  New  Jersey.  This  specimen  is  now  in  the  American  Museum  of  Natural  History  and 
has  the'number  1472.  Portions  were  figured  by  Cope,  and  it  seems  proper  to  regard  it  as  the 
type  of  the  species.  It  is  probable  that  the  description  of  a  specimen  from  Hornerstown 
appeared  a  short  time  before  the  detailed  description  given  in  the  Extinct  Batrachia,  etc.;  but 
that  earlier  description  is  not  one  that  would  enable  us  to  determine  the  species,  no  part  was 
figured,  and  the  specimen  was  not  intended  by  Cope  to  stand  as  the  type. 

Of  the  carapace  (fig.  n2  )  Cope  figured  the  nuchal  and  the  right  and  left  first  peripherals. 
Portions  of  all  these  bones  are  now  missing.  The  anterior  outHne  of  the  carapace  was  rounded 
as  in  r.  longinuchus,  and  the  free  border  was  acute.  The  shell  appears  to  have  been  of  only 
moderate  convexity.  The  width  of  the  nuchal  anteriorly  was  50  mm.;  its  greatest  width,  close 
to  115  mm.;  its  length  was  probably  about  n5  mm.    Its  proportions  were  therefore  as  in  T. 


ii6 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


longiriuchus.  From  the  acute  edge  the  bone  thickens,  at  first  rapidly,then  gradually,  to  12  mm., 
at  the  middle  of  the  length.  The  first  peripheral  has  an  extent  of  82  mm.  along  the  free  border, 
and  80  mm.  from  this  to  the  hinder  border.  Its  thickness  is  about  that  of  the  nuchal.  The 
second  peripheral  measures  65  mm.  along  the  free  border.    The  edge  is  acute. 

None  of  the  hinder  peripherals  is  present,  but  there  are  parts  of  two  from  the  bridge 
region.    One  of  these  is  65  mm.  long  and  presents  2  faces,  which  meet  at  a  right  angle  along  an 


Fig.  112. — Taphrosphys  tiwlops.     Restoration  of  carapace  of  type.      Xj. 
Known  portions  represented  by  stippled  areas. 


No.  1472  A.  M.  N.  H. 


obtuse  lateral  carina.  Fig.  113  presents  sections  of  the  ends  of  this  bone,  a  showing  the  ante- 
rior end,  b,  the  posterior.  A  sulcus  crosses  both  faces  a  little  nearer  the  thicker  end.  The  width 
of  one  face,  probably  that  parallel  with  the  plastron,  is  43  mm.  The  other  peripheral  presents 
2  faces  meeting  at  an  acute  angle.  Fig.  1 14  shows  sections  of  the  ends  of  this  bone,  c  being  the 
anterior  end,  (/,  the  posterior.    The  length  of  the  bone  is  60  mm.     It  seems  quite  certain  that 


BOTHREMYDIDiE. 


117 


the  peripheral  with  the  obtuse  carina  is  the  more  anterior,  the  one  with   the  acute  carina 
belonging  near  the  inguinal  notch. 

Portions  of  the  right  and  left  first  costals  are  present.  These  fragments  show  that  these 
bones  had  an  antero-posterior  width  ot  about  no  mm.  The  thickness  at  the  neural  border  is 
between  9  mm.  and  10  mm.  On  the  inferior  side  of  the  bone  is  seen  the  base  of  the  rib-head; 
in  front  of  this  a  sharp  ridge  corresponding  to  the  first  rib.  Each  of  the  first  costals  articulated 
with  four  peripherals.  A  ridge  proceeding  from  the  rib-head  becomes,  toward  the  peripheral 
border,  high  and  broad.    In  this  is  excavated  a  large  pit,  20  mm.  wide  and  rising  about  50  mm. 


b 


113.  114.  115. 

Figs.  113-115. — Taphrosphys  molops.      Xj.     Xo.  1472  A.  M.  N.  H. 

113.  Sections  of  a  bridge  peripheral,    a,  anterior  end;  6,  posterior  end. 

114.  Sections  of  another  peripheral  of  bridge,    c,  anterior  end;    d,  posterior  end. 

115.  First  costal,  inner  surface.    Shows  axillary  pit. 

above  the  lower  border  of  the  costal  (fig.  115  ).    This  is  for  the  reception  of  the  axillary  buttress. 
Its  upper  end  is  much  the  deeper. 

There  are  fragments  of  the  second,  third,  fourth,  fifth,  and  sixth  costals.  These  are 
represented  in  the  restoration  (fig.  112).  From  the  proximal  end  of  costals  three  and  four  we 
get  an  idea  of  the  forms  of  neurals,  but  only  approximate  information  regarding  their  widths. 
The  third  costal  is  12  mm.  thick  at  the  neural  border  but  only  6  mm.  at  the  distal  end.  The 
fifth  and  the  sixth  costals  are  wider  than  those  preceding  them,  as  in  T.  longinuchus. 


Fig.   116. — Taphrosphys  molops.     Anterior  half  of  p]a,stron  of  type.      X}. 
Known  portion.s  stippled,     m.p,  mesoplastron. 

The  upper  surface  of  the  nuchal  and  the  anterior  peripherals  is  rather  strongly  sculptured 
with  a  network  of  grooves.  The  interspaces  vary  greatly  in  form  and  size,  few  being  less  than 
5  mm.  in  diameter.  Of  the  bridge  peripherals  one  face  is  distinctly  sculptured,  the  other 
obsoletely  so.  The  sculpture  on  the  costals  is  distinct,  but  usually  not  so  strongly  exprest  as  on 
the  nuchal.     The  deepest  furrows  are  mostly  nearly  parallel  with  the  long  axis  of  the  costal. 

The  sulci  are  shallow  but  distinct.  There  is  no  nuchal  scute.  The  sulcus  between  the 
first  marginals  is  58  mm.  long.  Each  measures  66  mm.  along  the  free  border.  The  second 
marginals  had  an  equal  extent  along  the  free  border.  The  width  at  the  anterior  end  is  60  mm.; 
at  the  distal  end,  40  mm. 


Il8  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

The  first  vertebral  scute  had  a  length  of  about  90  mm.,  a  width  of  about  140  mm.  in  front 
and  of  about  80  mm.  behind.  The  approximate  proportions  of  the  next  three  are  shown  in  the 
restoration. 

Cope  figured  (Ext.  Batr.,Rept.,  etc.,  p.  160,  fig.  43)  a  considerable  part  of  the  anterior  lobe 
of  the  plastron.  Another  portion  of  the  same  specimen  has  been  found,  the  border  of  the  left 
axillary  region,  and  this  is  included  in  fig.  1 16.  This  specimen  suflices  to  give  us  a  clear  idea 
of  the  form  of  the  anterior  half  of  the  plastron.  This  lobe  had  a  length  of  about  135  mm.  and 
a  width  of  about  260  mm.  It  was  rounded  in  front,  with  a  slight  median  concavity.  The  free 
edges  are  obtuse,  except  at  the  union  of  the  epiplastrals  with  the  hyoplastrals.  The  thick- 
ness is  everywhere  close  to  10  mm.  The  entoplastron  was  diamond-shaped,  65  mm.  long  and 
86  mm.  wide.  The  suture  of  the  hyoplastron  with  the  hypoplastron  was  oblique  to  the  surfaces 
of  the  bones,  so  that  the  hyoplastron  overlaps  the  hypoplastron  somewhat.  A  portion  of  the 
axillary  region  is  preserved.  The  base  of  the  buttress  did  not  extend  far  within  the  free  border 
of  the  anterior  lobe. 

It  is  unfortunate  that  the  epiplastron  is  not  complete  to  the  midline,  for  we  are  left  in  some 
doubt  regarding  the  more  anterior  scutes.  An  intergular  occupied  a  large  part  of  the  entoplas- 
tron. Cope  represented  this  as  overlapping  some  distance  on  the  epiplastrals,  but  it  seems  to 
the  writer  that  a  sulcus  crosses  the  entoplastron  close  to  its  anterior  border.  Probably  the 
gulars  met,  possibly  coalesct,  at  the  midline,  in  front  of  the  intergular.  The  humerals  occu- 
pied the  hinder  half  of  each  of  the  epiplastra.  In  some  specimens  of  this  genus  there  seems  to 
be  a  scute  cut  oflF  from  the  inner  end  of  each  gular.  Such  a  scute,  or  such  scutes,  would  be 
without  name.  Better  specimens  are  required  to  settle  this  matter.  The  arrangement  of  the 
scutes  in  this  region  appears  to  resemble  that  of  Chelodina.  The  pectorals  measure  87 
mm.  along  the  midline;  the  abdominals  occupy  the  posterior  26  mm.  of  the  hyoplastra. 

Cope  presents  a  figure  of  the  hinder  half  of  the  plastron  of  this  specimen.  It  is  difficult  to 
determine  just  how  much  of  that  part  of  the  plastron  was  in  his  hands.  At  present  there  is 
with  the  specimen  only  a  fragment  of  the  left  inguinal  region,  a  fragment  of  the  left  xiphiplas- 
tron,  and  the  hinder  angle  of  the  right  xiphiplastron.  The  latter  is  marked  in  Cope's  figure 
with  the  letters  Is.  The  fragment  of  the  inguinal  region  extends  forward  to  the  suture  with 
some  bone,  probably  the  mesoplastron.  On  the  upper  surface  about  40  mm.  behind  this 
suture  is  a  prominent  ridge,  the  base  of  the  inguinal  buttress.  This  ridge  is  much  more 
strongly  developt  than  in  T.  longinuchus. 

The  base  of  the  xiphiplastron  presents  a  coarse  suture  with  the  hypoplastron.  The  free 
border  of  the  bone  is  acute.  From  the  edge  the  bone  thickens  to  12  mm.  On  the  upper 
surface  of  this  bone  is  a  part  of  the  much  elevated  and  rough  articulating  surface  for  the  pubis. 
On  the  hinder  angle  of  the  xiphiplastron  is  the  circular  elevated  and  rough  surface  for  articu- 
lation with  the  ischium.    The  notch  in  the  rear  of  the  plastron  was  about  140  mm.  wide. 

On  the  anterior  half  of  the  plastron  there  is  little  evidence  of  sculpture.  It  is  more  conspic- 
uous on  fragments  of  the  hinder  half,  where  it  consists  of  a  network  of  grooves. 

Cope  mentions  a  specimen  of  this  species  from  Hornerstown,  New  Jersey,  which  displayed 
the  mesoplastral  bones.  These  presented  a  rounded  interior  outline  and  were  applied  to  an 
equal  extent  of  the  hyoplastrals  and  the  hypoplastrals.  They  reacht  one-third  the  distance 
toward  the  midline.  The  plastron  was  10.5  inches  between  the  inguinal  notches.  The  speci- 
men is  now  lost. 

Another  specimen.  No.  1343  of  the  American  Museum,  an  individual  a  little  larger  than 
the  type,  shows  a  portion  of  the  right  hyoplastron  from  front  to  rear.  The  length  is  170  mm. 
Just  behind  the  axillary  buttress  the  posterior  sutural  border  makes  a  turn  forward  at  nearly 
a  right  angle.  It  appears  evident  that  this  was  to  receive  the  mesoplastron.  No.  1474  of 
the  American  Museum,  a  part  of  the  Cope  collection  of  fossil  reptiles,  was  obtained  by  Cope, 
February  22,  1871,  and  therefore  not  mentioned  in  his  monograph  of  1869  and  1870.  It 
came  from  Birmingham,  Burlington  County,  New  Jersey.  It  furnishes,  besides  some  fragments 
of  costals,  a  large  part  of  both  hypoplastra  and  the  complete  left  xiphiplastron  (figs.  1 17,  1 18). 
The  individual  was  of  almost  exactly  the  same  size  as  the  type.  The  distance  along  the  median 
line,  from  the  hyohypoplastral  suture  to  the  bottom  of  the  notch  in  the  rear,  is  243  mm.  The 
left  hypoplastral  came  into  contact  with  the  right  xiphiplastron,  an  irregularity  not  uncommon 
in  the  early  turtles.    The  right  hypoplastron  is  115  mm.  long;  the  left  xiphiplastron,  105  mm.; 


BOTHRK.MYDIDiE. 


119 


both  measured  at  the  midhne.    Neither  hypoplastron  exhibits  either  the  inguinal  region  or  the 
border  for  the  mesoplastron. 

The  hyoplastron  overlapt  somewhat  the  hypoplastron,  and  the  latter  similarly  overlapt 
the  xiphiplastron.  At  the  antero-interior  angle  the  hypoplastra  are  16  mm.  thick;  at  the 
postero-interior  angle,  8  mm.  The  whole  free  border  of  the  hinder  lobe  is  acute.  The  hinder 
notch  is  135  mm.  wide,  and  42  mm.  deep.    On  the  upper  surface  of  the  xiphiplastron  (fig.  1 18) 


-Taphrosphys  molops. 

117.  Hinder  half  of  plastron  seen  from  below.     X}.    No.  1474  A.  M.  N.  H.     Known  hones  inclosed  hy  solid  lines. 

118.  Upper  surface  of  left  xiphiplastron.     Xl-     No.  1474  A.  M.  N.  H.     Shows  ischiadic  and  puhic  articulations. 

119.  Three  neural  hones.    Xj.     No.  1470  A.  M.  N.  H. 

are  seen  the  circular  scar  for  the  ischium  and  the  elongated  one  for  the  pubis.    Both  are  elevated 
and  furnisht  with  sharp  ridges. 

The  inferior  surface  of  this  part  of  the  plastron  is  rough,  due  partly  at  least  to  erosion. 
The  abdominal  scutes  occupy  about  the  anterior  30  mm.  of  the  hypoplastra.  The  femorals 
are  large,  measuring  about  135  mm.  along  the  midline;  the  anals,  75  mm. 

The  specimen  of  this  species  mentioned  by  Cope  as  having  come  from  Birmingham  is  now 
No.  iiZQofthe  American  Museum.  The  femur  supposed  by  Cope  to  belong  with  the  specimen 
is  missing.    The  remaining  fragments  throw  no  light  on  the  species. 

No.   1470  of  the  American  Museum  is    labeled  by 
^^-v^  Cope  as  having  been  received  by  him  "9/8,  1870,"  and 

was  therefore  not  mentioned  in  his  monograph.  It  was 
secured  at  Barnesboro.  The  individual  was  somewhat 
larger  than  the  type.  The  nuchal  bone  has  a  length  ot 
107  mm.,  a  width  anteriorly  of  64  mm.,  and  a  maximum 
width  of  117  mm.  The  notch  in  the  midline  behind,  for 
the  first  neural,  is  only  24  mm.  wide.  Three  neural 
bones  (fig.  119)  accompany  the  lot,  but  the  exact  position 
of  none  of  them  can  be  determined.  None  shows  a  cross- 
ing sulcus,  and  yet  two  of  them  were  in  contact.  Figures 
\  of  these  are  presented. 

\  The  right  first  costal  shows  a  great  pit  for  the  axillary 

,^--''  buttress.    A  fragment  of  the  right  fifth  presents  the  some- 

r  cr  ./       .;  ;  .,       i>  -  what  eroded   ridge  and  elongated  pit  for  the  inguinal 

Fig.  120. — Taphrosphys  mnhps.     Vox-  """»•-  ^        _,      ,  *^         .  ^        ■  .'^     ^,  ,■      „.,..■, 

f  .J    ■  A     ■  1  lu       o^oi  buttress      The   atter  is  10  mm.  wide.     I  he  pubic  scai  is 

tions   of  seventh    and   eighth    costal  uumcss.      ±  nv,  lan^.  .0         .,        ,  ,1  1       tl 

bones  and  part  of  suprapygal.     No.  53  mm.  long  and  1 5  mm.  wide,  elevated  and  rough.     1  he 

1477  A.  M.  N.  H.  pubic  scar  is  circular. 


120  FOSSIL  TURTLES    OF    NORTH    AMERICA. 

Cope  described  a  specimen  from  Barnesboro  (Ext.  Batr.,  Rept.,  etc.,  p.  i6i)  which  is 
important  because  on  it  he  based  the  distinction  between  his  Taphrosphys  and  Prochonias. 
The  specimen  is  No.  1477  of  the  American  Museum.  Cope  states  that  this  specimen  exhibits 
an  azygous  bone  in  contact  with  the  caudal  marginal.  As  a  matter  of  fact,  all  the  species 
possess  such  a  bone,  the  suprapygal,  but  Cope  evidently  meant  a  bone  still  in  front  of  this. 
He  states  that  this  appeared  to  be  the  co-ossified  proximal  portions  of  the  last  pair  of  costals 
and  that  the  fragment  appeared  to  be  bounded  posteriorly  by  a  continuous  suture.  A  close 
examination  of  the  region  in  question  shows  that  it  is  identical  in  structure  with  the  same 
region  in  T.  sulcatus.  A  figure  of  the  fragment  is  presented  (fig.  120).  The  costals  of  the 
eighth  pair  meet  in  the  midline,  as  usual.  Behind  them  there  is  the  anterior  end  of  the 
suprapygal.  Cope  overlookt  the  sutures  between  the  suprapygal  and  the  eighth  costals  and 
the  suture  between  the  contiguous  ends  of  the  costals  just  mentioned.  The  xiphiplastron  is 
present  and  shows  the  features  described  by  Cope.  The  epiplastron  lacks  the  outer  end.  On 
the  free  border,  at  a  distance  of  48  mm.  from  the  symphysis,  begins  the  gulo-humeral  sulcus,  as 
in  the  figure  of  the  type.  There  appears  to  be  no  sulcus  nearer  the  symphysis.  Furthermore,  no 
sulcus  is  seen  running  in  front  of  the  suture  with  the  hyoplastron  and  toward  the  opposite  side. 

Cope  described  a  variety  enodis  of  this  species.  The  specimen  on  which  this  was  based  has 
not  been  seen  by  the  present  writer.  According  to  Cope's  description  the  free  border  of  the 
hypoplastron  was  of  equal  thickness  and  equally  obtuse,  differing  thus  from  the  typical  speci- 
mens of  T.  molops.  Also  the  free  margin  of  the  hyoplastral  was  comprest  and  acute.  It  may 
be  a  distinct  species. 

Taphrosphys  dares  sp.  nov. 
Figs.  121-124. 

No.  II 27  of  the  American  Museum  of  Natural  History  belongs  to  portions  of  a  fossil 
turtle  which  is  a  part  of  the  Cope  collection  of  fossil  reptiles.  No  label  came  with  the  speci- 
men to  tell  what  was  its  origin.  The  matrix  adhering  to  the  bones  shows  that  the  fossil  did  not 
come  from  the  greensand  of  New  Jersey.  It  consists  of  a  yellowish  or  reddish  sand  in  which 
are  small  flakes  of  mica.  In  his  monograph  of  1869  and  1870  Cope  states,  on  page  167,  that 
he  had  received  some  portions  of  a  Taphrosphys  from  North  Carolina,  but  the  brief  descrip- 
tion given  by  him  does  not  agree  sufficiently  with  the  specimens  here  numbered  1127.  Cope 
had  also  seen  specimens  of  what  he  regarded  as  T.  strenuus  from  Georgia,  and  it  appears  proba- 
ble that  these  are  the  ones.  Further  attention  is  given  this  matter  below.  It  had  evidently  been 
Cope's  intention  to  describe  and  figure  these  bones  for  he  has  indicated  on  them  that  they  were 
to  be  numbered  I,  2,  3,  and  4. 

Wherever  these  bones  were  found,  it  is  quite  certain  that  they  belong  to  a  species  hitherto 
undescribed,  and  were  from  the  Upper  Cretaceous.  The  lot  presents  the  distal  end  of  a  fifth 
costal,  probably  the  right,  most  of  a  right  peripheral,  the  seventh  or  the  eighth,  the  entoplastron, 
a  large  portion  of  the  left  xiphiplastron,  and  a  fragment  of  the  right  xiphiplastron. 

The  fragment  of  costal  has  a  length  of  180  mm.  and  a  width  of  85  mm.  One  border  has 
a  thickness  of  11  mm.;  the  other,  of  16  mm.  The  thicker  sutural  border  presents  a  sort  of 
tongue,  the  middle  layer  of  the  bone  projecting  beyond  the  outer  and  the  inner.  The  thinner 
sutural  border  has  the  outer  and  the  inner  layers  projecting  beyond  the  middle,  so  that  the  edge 
is  grooved.  The  sutures  between  the  costals  seem  therefore  to  have  formed  what  carpenters 
call  a  tongue-and-groove  joint.  At  the  distal  end  of  the  costal,  on  the  thicker  side,  is  a  rough 
surface  which  indicates  that  the  costal  was  slightly  overlapt  by  one  of  the  peripherals. 

The  upper  surface  of  this  bone  is  smooth,  but  it  is  markt  by  a  coarse  network  of  shallow 
and  thread-like  grooves. 

On  the  inferior  side  of  this  costal,  nearer  the  thicker  side,  is  a  pit  for  the  reception  of  the 
inguinal  buttress  of  the  plastron.  This  pit  is  excavated  in  the  summit  of  a  ridge,  the  rib  proper. 
The  pit  has  a  length  of  60  mm.  and  a  width  of  23  mm.  Its  upper  end  is  placed  105  mm. 
above  the  lower  border  of  the  costal.  Below  it  is  a  rough  surface  which  probably  joined  a 
portion  of  the  buttress.  Altogether  it  appears  that  this  costal  belonged  to  the  right  side;  in 
which  case  the  thicker  border  was  the  hinder  one. 

The  peripheral,  the  seventh  or  the  eighth  of  the  right  side,  is  massive  (fig.  121).  Unfor- 
tunately the  free  border  is  everywhere  broken  away,  so  that  we  can  not  be  certain  whether  it 


BOTHREMYDIDj*. 


121 


was  acute  or  obtuse;  but  the  probability  is  that  it  was  acute.  At  one  point  it  runs  down  to  a 
thickness  of  only  11.5  mm.  The  fore-and-aft  extent  of  the  bone  is  84  mm.  The  anterior 
border  is  very  thick,  52  mm.  at  one  section;  and  is  excavated  to  form  a  part  of  the  sternal 
chamber.  The  hinder  border  was  not  more  than  15  mm.  thick.  The  upper  border  joined  the 
ends  of  2  costal  bones,  proof  that  the  peripheral  does  not  belong  to  the  axillary  region  of  the 
left  side. 

F~igure  122  is  a  section  which  is  taken  20  mm.  to  the  left  of  the  front  border.  The  costal 
that  articulated  with  the  anterior  half  overlapt  the  peripheral,  but  the  succeeding  one  was 
overlapt  by  the  peripheral.  Satisfactory  contact  is  not  obtained  between  the  peripheral  here 
described  and  the  fifth  costal  above  described,  so  that  their  exact  relations  are  not  known. 

The  upper  surface  of  the  peripheral  (fig.  121)  is  ornamented  by  a  network  of  grooves 
similar  to  those  of  the  costal,  but  forming  a  much  closer  reticulation.  That  portion  of  the 
inferior  surface  of  the  peripheral  covered  by  horn  has  a  still  closer  network  of  grooves.  On  the 
upper  surface  is  seen  a  triradiate  sulcus,  which  bounds  a  portion  of  the  third  costal  scute  and 
portions  of  two  marginals. 

Fig.  123  represents  the  entoplastron.  Its  length  is  84  mm.;  its  width,  109  mm.;  its 
greatest  thickness,  14  mm.  In  the  hinder  border  is  a  constriction.  The  outer  surface  presents 
neither  sculpture  nor  distinct  traces  of  sulci. 


Figs.  121-124. — Taphrosphys  dares.     Parts  of  the  type.      X^.     No.  1127  A.  M.  N.  H. 


121.  Seventh  or  eighth  peripheral,  upper  surface. 

122.  Section  of  peripheral  of  fig.  121. 


123.  Entoplastron 

124.  Section  along  hypoxiphiplastral  suture. 


The  left  xiphiplastron  is  present  from  the  anterior  border  to  the  hinder  end  of  the  pubic 
scar.  Its  greatest  width  is  140  mm.;  so  that  the  hinder  lobe  was  280  mm.  wide  at  the  hypo- 
xiphiplastral suture.  This  suture  was,  as  seen  from  below,  a  very  close  one;  seen  from  above, 
the  adjoining  bones  sent  coarse  digitations  into  each  other.  The  anterior  end  of  the  right 
xiphiplastron  overlapt  the  left  as  much  as  28  mm.  The  median  suture  was  jagged  above, 
but  more  even  on  the  under  side.  Near  the  antero-median  angle  the  bone  is  17  mm.  thick; 
the  postero-median  portion,  12  mm.  The  free  border,  for  some  distance  behind  the  hypo- 
xiphiplastral suture,  is  thin  and  acute.  Fig.  124  is  a  section  taken  near  the  suture.  The  notch 
in  the  upper  surface  was  filled  by  a  digitation  from  the  hypoplastron.  On  the  upper  surface 
of  the  bone  is  a  large  elevated  area  which  articulated  with  the  pubis.  This  articulation  is 
much  eroded.  Its  length  was  about  66  mm.;  its  width,  about  27  mm.  The  lower  surface  of 
the  bone  shows  no  distinct  sculpture.  The  femoro-anal  sulcus  crosses  the  bone,  beginning  at 
the  median  line  about  45  mm.  behind  the  hypoxiphiplastral  suture  and  meeting  the  free  border 
about  66  mm.  behind  the  suture. 

What  appears  to  be  a  portion  of  the  right  xiphiplastron  is  preserved.  It  bears  the  elevated 
articulation  for  the  ischium.  On  the  left  is  a  part  of  the  median  suture.  The  articulation  for 
the  ischium  is  about  48  mm.  long  and  17  mm.  wide.  Unless  there  is  some  error  regarding  this 
bone,  the  notch  in  the  hinder  lobe  must  have  been  quite  different  from  that  of  the  other  species 
of  the  genus. 


122  FOSSIL  TURTLES   OF   NORTH   AMERICA. 

While  related  to  T.  strenuus,  this  species  shows  several  differences.  So  far  as  the  sculpture 
of  the  costals  can  be  compared,  that  of  T.  strenuus  consisted  of"  more  numerous  and  deeper 
grooves.  The  entoplastron  of  T.  strenuus  was  much  larger  than  that  of  the  species  here 
described.  As  shown  by  the  section  taken  at  the  junction  with  the  hypoplastron  the  xiphi- 
plastron  of  T.  strenuus  thickened  much  more  rapidly  and  from  a  less  acute  edge,  and  its 
hinder  portion  was  considerably  thicker  than  in  T.  dares. 

In  the  collection  of  the  Geological  Survey  of  Georgia,  at  Atlanta,  are  some  portions  of  a 
turtle  which  appears  to  belong  to  this  species.  Indeed,  there  are  reasons  for  believing  that  they 
are  portions  of  the  same  individual  as  the  type  bones.  They  are  believed  to  have  been  secured 
in  the  same  locality  and  formation  as  the  carapace  of  Peritresius  ornatus;  that  is,  on  Bonna- 
hachee  Creek,  Stewart  County,  Georgia,  in  the  Ripley  formation,  of  the  Upper  Cretaceous. 

Among  the  fragments  is  one  including  apparently  the  anterior  inner  angle  of  the  hypo- 
plastron. Sixty  mm.  behind  the  supposed  hyohypoplastral  suture  the  thickness  is  26  mm. 
Toward  the  suture  mentioned  the  thickness  is  reduced.  Here  the  upper  two-thirds  of  the  bone 
is  beveled  off,  showing  that  the  hyoplastron  somewhat  overlapt  the  hypoplastron. 

Another  plastral  fragment  belongs  probably  to  the  hypoplastron  behind  the  inguinal  notch. 
Toward  the  median  longitudinal  suture  the  thickness  is  16  mm.  Toward  the  free  border  the 
thickness  is  much  reduced,  but  the  edge  is  rounded.  The  xiphiplastral  bone  in  the  American 
Museum  shows  that  as  the  free  border  was  continued  backward  it  became  acute. 

Another  bone  appears  to  be  the  second  peripheral.  It  is  100  mm.  long  on  the  subacute 
free  border.  The  height  was  originally  at  least  82  mm.  and  the  greatest  thickness  is  25  mm. 
The  upper  surface  is  convex  from  end  to  end,  nearly  plane  up  and  down. 

Named  after  Dares,  a  pugilist  beaten  in  an  encounter  described  in  the  MneiA,  book  v. 

Taphrosphys  nodosus  Cope. 

Taphrosphys  nodosus,  CoPE,  Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1870,  pp.  159,  167,  plate  i,  fig.  16;  Vert. 
Cret.  Form.  West,  1875,  p.  264. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  438. 

The  type  of  the  present  species  forms  No.  1480  of  the  American  Museum  of  Natural 
History.  The  remains  are  evidently  those  of  a  large,  thin-shelled  turtle;  but  these  remains 
are  meager  and  fragmentary.  They  were  obtained  at  Hornerstown,  Monmouth  County,  New 
Jersey,  apparently  from  the  uppermost  bed  of  Cretaceous  greensand.  The  fragments  are 
charged  with  iron  pyrites  and  are  disposed  to  fall  to  pieces.  Portions  of  costals  are  to  be 
recognized  and  a  peripheral  or  two. 

Cope  figured  portions  of  2  costals.  His  fig.  16  is  from  a  fragment  58  mm.  wide  and  10  mm. 
thick,  but  the  inferior  layer  of  the  bone  has  peeled  off.  Another  bone  which  comes  down  to  an 
acute  edge  is  probably  a  peripheral.  Its  thickness  at  a  distance  of  25  mm.  from  the  edge  is 
9  mm.;  still  farther  away,  it  becomes  12  mm.  Another  piece  of  bone  is  part  of  a  bridge 
peripheral,  having  two  sculptured  faces  at  about  a  right  angle  with  each  other. 

The  sculpture  will,  more  than  anything  else,  assist  in  the  recognition  of  the  species.  This 
consists  of  pits  and  grooves,  the  latter  anastamosing  more  or  less  and  separating  tortuous 
ridges  and  pustules.  The  general  effect  is  that  seen  on  the  carapace  of  a  coarsely  sculptured 
trionychid.    About  4  ridges  are  crost  by  a  line  20  mm.  long. 

This  species  will  perhaps  eventually  be  found  to  belong  to  a  genus  distinct  from  Taph- 
rosphys. Indeed,  the  present  writer  knows  of  no  characters  distinguishing  it  from  Peritresius 
ornatus  (Leidy). 

Genus  AMBLYPEZA  nov. 

A  genus  of  pleurodirid  turtles  which  differs  from  Taphrosphys  in  having  the  nuchal  bone 
shorter  and  its  front  relatively  broader  and  in  having  the  free  borders  of  the  hinder  peripherals 
thick  and  obtuse.    Apparently  a  nuchal  scute  was  present. 

Type:  J mhly peza  entellus  Hay. 

Amblypeza  entellus  sp.  nov. 

Figs.  125-132. 

The  type  of  this  species  is  a  lot  of  bones  which  belong  to  the  collection  of  the  Geological 
Survey  of  New  Jersey,  and  which  were  loaned  to  the  writer  by  the  present  State  geologist,  Dr, 


BOTHREMYDID^. 


123 


Henry  B.  Kiimmel.  These  bones  had  lain  for  many  years  in  the  basement  of  the  capitol  and 
all  knowledge  of  their  origin  had  been  lost.  Without  doubt,  they  had  been  obtained  from  the 
Upper  Cretaceous  greensand  of  New  Jersey. 

Of  this  individual  there  are  large  portions  preserved,  but  there  are  so  many  parts  missing 
that  the  shell  can  be  only  partially  restored.  Of  the  carapace  there  were  secured  a  considerable 
part  of  the  anterior  and  posterior  free  borders  and  some  fragments  of  costals.  Of  the  plastron 
some  important  parts  can  be  identified.  The  individual  is  estimated  to  have  had  a  carapace 
about  700  mm.  long. 

Most  of  the  nuchal  bone  is  present  (fig.  125),  but,  on  account  of  the  absence  of  a  section  of 
it,  its  exact  width  can  not  be  determined.  It  was  not  far  from  120  mm.  The  hinder  portion  is 
missing.  The  thickness  near  the  midline  in  front  is  13  mm.;  backward  the  bone  thins  to 
6  mm.,  while  at  its  outer  ends  it  is  18  mm.  thick.  The  whole  free  edge  is  obtuse.  The  first 
peripheral  (fig.  125)  has  a  length  along  the  free  border  of  83  mm.,  a  fore-and-aft  extent  of 
65  mm.  The  thickness  at  the  suture  with  the  second  peripheral  is  24  mm.;  at  the  suture 
with  the  first  costal,  8  mm.  The  second  peripheral  (fig.  125)  extends  90  mm.  along  the  free 
border;  70mm.  fore  and  aft;  and  is  26  mm.  thick  where  it  joined  the  third.  Its  hinder 
border  somewhat  overlapt  the  first  costal. 


Figs.  125-130. — Amhlypeza  entellus.     Portions  of  the  type  in  State  collection  of  New  Jersey. 

125.  Nuchal  and  anterior    peripherals   of   type.     X}.  127.  .Section  along  intermarginal  sulcus  of  peripheral 

nu.pj  nuchal  plate;   nu.  5,  nuchal  scute;  pfr.  i,  of  fig.  126.    Xj. 

first  peripheral.  128.  Hinder  peripheral.     Xj. 

126.  Hinderperipherals(7?and8!')ofleft  sideof  type.  X}.  129.  Section  of  peripheral  of  fig.  128.     Xj. 

130.  Inner  surface  of  fifth  costal.  Xj.  Shows  surface  for  inguinal  buttress. 

The  peripherals  behind  the  bridges  were  larger  and  thicker  than  those  in  front.  One 
whole  one  and  portions  of  two  others  are  present.  The  free  borders  of  these  are  thickened  and 
very  obtuse,  thus  contrasting  strongly  with  the  corresponding  bones  of  Taphrosphys.  The 
exact  positions  of  these  posterior  peripherals  can  not  be  made  out.  Fig.  126  represents  portions 
of  two;  and  from  the  thickness  of  the  bone  at  the  left  hand,  27  mm.,  and  the  height  of  the 
costo-marginal  sulcus,  that  peripheral  is  believed  to  belong  not  far  from  the  inguinal  notch, 
being  possibly  the  left  eighth.  Fig.  127  is  a  section  taken  along  the  intermarginal  sulcus.  The 
upper  surface  is  convex  in  all  directions.  On  the  under  side  the  horn-covered  surface  rose 
above  the  free  border  about  45  mm.,  descending  somewhat  backward.  Fig.  128  represents  a 
complete  peripheral,  probably  the  tenth  of  the  right  side;  fig.  129  is  a  section  of  the  anterior 
end.  It  measures  104  mm.  along  the  free  border  and  is  104  mm.  high.  The  thickness  near  the 
lower  border  is  21  mm.;  at  the  upper  border,  13  mm.  On  the  visceral  side  the  surface  covered 
with  horn  is  40  mm.  wide  anteriorly,  but  toward  the  hinder  end  is  only  15  mm.  wide.  The  free 
border  is  very  obtuse. 

A  fragment  of  a  costal  has  a  length  of  130  mm.,  a  width  of  JJ  mm.,  and  a  thickness  of 
15  mm.  at  the  sutural  border,  20  mm.  through  the  rib.    Another  fragment  is  part  of  the  fifth 


124 


FOSSIL    TURTLES    OK    NORTH    AMERICA. 


costal  (fig.  130)  and  shows  the  scar  for  the  articulation  of  the  inguinal  buttress.  This  fragment 
is  91  mm.  wide,  13  mm.  thick  at  the  sutural  border,  and  29  mm.  thick  through  the  ridge  in 
which  is  excavated  the  pit  for  the  inguinal  buttress.  This  pit  is  shallow  and  quite  different 
from  that  of  any  species  of  Taphrosphys. 

The  sculpture  of  the  anterior  peripherals  is  obscure,  due  probably  to  weathering;  that 
of  the  hinder  peripherals  is  more  distinct.  It  is  very  different  from  that  of  Taphrosphys  dares, 
and  consists  of  a  pretty  close  network  of  rather  broad  grooves.  On  the  costals  the  interven- 
ing spaces  are  about  as  broad  as  the  grooves  and  the  latter  run  mostly  parallel  with  the  long 
axis  of  the  bone. 


Figs.  131  and  132. — Amhlypeza  entellus.     Known  parts  shown  by  stippling. 
131.  Restoration  of  anterior  lobe  of  plastron.     Xj.         iji.  Restoration  of  hinder  half  of  plastron  of  type.     X^. 

Appearances  indicate  that  there  was  a  nuchal  scute  about  60  mm.  wide.  If  this  be  true, 
the  generic  distinctions  are  strengthened.  The  sulci  are,  however,  obscure.  The  first  vertebral 
scute  extends  much  nearer  the  front  of  the  nuchal  bone  than  in  any  species  of  Taphrosphys. 
At  the  midline  the  distance  is  only  20  mm.  If  there  is  a  nuchal  scute,  the  first  marginal 
measures  only  64  mm.  along  the  free  border  of  the  carapace.  The  width  at  the  proximal  end 
is  24  mm.;  at  the  distal  end  it  has  increast  to  40  mm.  The  second  marginal  is  86  mm.  long 
and  60  mm.  high  at  the  middle  of  the  length.  The  marginal  lying  on  the  supposed  eighth  and 
ninth  peripherals  is  102  mm.  long  and  85  mm.  high  in  front.  On  the  supposed  tenth 
peripheral  the  marginal  descended  to  within  42  mm.  of  the  lower  border  of  the  bone. 


BOTHREMYDID^. 


'25 


The  bones  of  the  plastron  (figs.  131,  132)  are  so  fragmentary  and  contacts  between  the 
pieces  so  rare  that  it  is  difficult  to  obtain  measurements.  The  right  epiplastron  (fig.  131)  is 
represented  by  two  fragments.  One  of  these  furnishes  the  symphysis.  This  is  36  mm.  long 
and  the  bone  is  22  mm.  thick.  The  hinder  border  was  in  contact  with  the  entoplastron  and  is 
18  mm.  thick.  The  other  fragment  furnishes  the  hinder  end  of  the  epiplastron.  There  is 
missing  probably  only  a  few  millimeters  of  bone  between  the  two  pieces.  The  epiplastron,  and 
therefore  the  whole  anterior  lobe,  was  of  a  different  form  from  what  we  see  in  Taphrosphys 
strenuus.  From  the  obtuse  free  border  of  the  epiplastron  to  the  entoplastron  was  nearly 
70  mm.  If  the  restoration  here  attempted  approaches  correctness  the  entoplastron  must  have 
been  at  least  200  mm.  wide. 

The  hypoplastra  at  their  inner  anterior  angles  are  23  mm.  thick.  The  upper  layers  of 
the  hyoplastra  overlapt  somewhat  the  hypoplastra. 

Of  the  hinder  lobe  (fig.  132)  there  are  preserved  several  pieces.  The  restoration  of  this 
lobe  has  been  attempted  and  the  recognized  pieces  of  the  lobe  are  represented  by  the  stippled 
areas.  On  the  right  side  is  seen  a  fragment  which  extends  from  near  the  inguinal  notch  to  the 
hypoxiphiplastral  sulcus.  The  free  border  is  rather  obtuse,  but  becomes  less  so  toward  the 
suture.  The  upper  surface  rises  rapidly  about  40  mm.  and  the  thickness  becomes  20  mm.  On 
the  left  side  is  a  fragment  presenting  a  portion  of  the  hypoplastron  and  no  mm.  of  the  free 
border  of  the  xiphiplastron.  The  border  may  be  called  subacute.  Three  pieces  of  the  right 
xiphiplastron  enable  us  to  make  out  its  characters;  two  of  these  form  close  contact  and  give  us 
the  hinder  angle  and  the  notch.  The  other  piece  bears  on  its  upper  surface  the  eroded  elevated 
scar  for  articulation  with  the  pubis.  It  appears  to  have  the  size  and  form  seen  in  the  species  of 
Taphrosphys.    Just  outside  of  this  surface  the  bone  is  17  mm.  thick. 

The  notch  in  the  rear  of  the  plastron  had  a  width  of  about  185  mm.  and  a  depth  of  about 
80  mm.  As  the  backwardly  projecting  angle  of  the  xiphiplastron  is  approacht  the  bone 
thickens  and  the  free  border  becomes  very  obtuse.  The  thickness  just  outside  the  ischiadic 
scar  is  18  mm.    The  latter  was  elevated  and  rough,  and  apparently  pear-shaped  in  outline. 

The  anterior  end  of  the  epiplastron  is  ornamented  with  a  close  network  of  grooves,  which 
inclose  spaces  extremely  irregular  in  size  and  form.  On  the  hinder  end  of  the  bone  the  inclosed 
areas  are  larger,  more  elongated,  and  parallel  with  the  free  border  of  the  bone.  The  sculpture 
of  the  rear  of  the  plastron  is  similar  to  that  just  described.  It  is  obscure  on  the  central  portions 
of  the  plastron.  The  sulci  of  the  plastron  are  obscure.  On  the  epiplastron  there  is  a  gulo- 
humeral  sulcus  beginning  38  mm.  from  the  epiplastral  symphysis  and  running  backward 
and  a  little  outward  to  the  suture  with  the  entoplastron. 

This  species  is  dedicated  to  Entellus,  who,  though  old  and  lacking  confidence,  had  endur- 
ance and  beat  his  younger  opponent  (Virgil's  ^neid,  book  v). 

Genus  NAIADOCHELYS  nov. 

An  imperfectly  known  genus  of  Pleurodira,  having  the  plastral  surface  smooth,  the  hinder 
lobe  deeply  and  broadly  notcht,  and  a  large  elevated  ischial  articular  surface  which  extends  to 
the  midline. 

Type :    Naiadochelys  ingravata  Hay. 

This  genus  differs  from  Taphrosphys  in  having  the  lower  surface  of  the  plastron  smooth, 
instead  of  ornamented  with  longitudinal  or  anastomosing  grooves,  and  in  having  a  much  more 
extensive  articular  surface  for  the  ischium.  At  present,  only  the  hinder  half  of  the  xiphiplastron 
is  known. 

Naiadochelys  ingravata  sp.  nov. 

Fig-  133- 

This  species  is  based  on  a  fragment  furnishing  about  the  hinder  half  of  a  left  xiphiplastron. 
It  was  collected  in  the  year  1900,  by  Professor  F.  W.  Putnam,  having  been  brought  to  him  by 
Indians,  at  Chaco  Canyon,  New  Mexico.  The  geological  formation  whence  it  was  derived  is 
uncertain,  but  it  was  probably  the  Laramie,  which  is  well  developt  in  that  region.  The 
specimen  has  been  transferred  from  the  department  of  anthropology  of  the  American  Museum 
of  Natural  History  to  the  department  of  vertebrate  paleontology.  The  present  number  of  the 
specimen  is  6078.    The  small  amount  of  matrix  yet  clinging  to  specimen  is  a  yellow  sandstone. 


126  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

The  fragment  of  xiphiplastron  present  indicates  a  turtle  of  moderate  size,  but  furnisht 
with  a  very  thick  and  heavy  plastron.  It  is  estimated  that  the  plastron  had  a  total  length  of 
i8  inches  (about  460  mm.).     The  thickness,  to  the  summit  of  the  ischial  articular  surface, 

is  26  mm.;  at  the  base  of  this,  where  it  appears  to  be  rising 
toward  the  pubic  articular  surface,  19  mm.;  at  the  sutural 
border  for  union  with  the  bone  of  the  opposite  side,  11  mm. 
In  a  specimen  oiTnphros phys  molops.  No.  1474, these  measure- 
ments, in  the  order  given,  are  15  mm.,  10  mm.,  and  10  mm. 
This  specimen  is  estimated  to  have  had  a  plastron  21  inches 
long. 

The  lower  surface  of  the  bone  is  very  flat  and   smooth. 

From  the  outer  border  the  upper  surface  rises  at  first  rapidly, 

then  more  slowly,  to  the  base  of  the  articular  eminence,  being 

thus  convex.     From  the  hinder  border  the  upper  surface  rises 

more  and  more  steeply,  being  thus  concave.     The  articular 

surface  for  the  ischium  is  much  larger  than  in  Taphrosphys. 

"~"^  It   is   approximately  triangular  in  outline,  the  hinder  border 

Vni-    133-     Naiadochelys  itigia-     running  somewhat  parallel  with  the  hinder  border  of  the  bone, 

vata.     Portion  of  left  xiphi-     ^j^n^  j|^g  ^^j^j.  border  runs  parallel  with  the  outer  border 

plastron     forminc    the     type.        r    u     u  j      i       »».  r  »      ..  i-  -^      'i-l-        >•      1 

'    ,      ^^      ,     o  A    .«  -.-  ..        01  the  bone  and  about  2';  mm.  distant  irom  it.     Inis  articular 
XA.     No.  6078  A.  M.  N.  H.  ^  ,  ■    u  I.  jr  Jir     •  l        r 

surface  extends  mesially  to  the  midline,  difienng  thus  from 

Taphrosphys  and  resembling  Hydromedusa.     The  figure  presented  will  show  the  form  and 

extent  of  the  surface.     At  its  summit  it  has  been  somewhat  eroded,  and  the  border  at  the 

anterior  angle  may  have  been  slightly  extended.    Where  not  eroded,  the  summit  is  roughened 

to  afford  attachment  to  the  ischium.    At  the  anterior  angle  of  the  eminence  the  smooth  surface 

of  the  plastron  at  first  descends,  then  begins  to  ascend,  as  if  rising  toward  the  articular  eminence 

for  the  pubis;  but  no  part  of  this  is  present. 

SuperfamUy  CRYPTODIRA  Cope. 

Thecophorous  turtles  having  the  carapace  composed  of  neurals,  costals,  and  peripherals. 
The  neurals  in  a  few  cases  greatly  red\iced.  The  plastron  having  the  epiplastra  in  contact  with 
the  hyoplastra.  Entoplastron  occasionally  wanting.  Mesoplastrals,  so  far  as  known,  never 
present.  Temporal  roof  varying  from  complete  to  obsolete.  Pterygoids  extending  backward 
between  the  basisphenoid  and  the  quadrates.  Neck  bending  in  a  sigmoid  curve  in  a  vertical 
plane  and  capable  of  being  retracted  between  the  scapulae.  Elements  of  the  pelvis  never 
suturally  joined  to  the  carapace  and  the  plastron. 

Of  the  Cryptodira  there  are  8  families  and  about  140  living  species.  Their  geographical 
distribution  is  discust  on  page  31  and  illustrated  by  fig.  10.  To  a  greater  extent  than  the  mem- 
bers of  any  other  superfamily  the  Cryptodira  have  been  able  to  adapt  themselves  to  the  varying 
conditions  of  the  globe.  All  lands,  except  the  very  coldest  and  the  dryest,  have  been  occupied 
by  them.  Most  deserts  have  their  species.  Species  inhabit  forests  and  prairies,  swamps, 
rivers,  lakes,  and  the  high  seas.  Their  structure  varies  accordingly.  By  their  wide  geograph- 
ical distribution,  the  number  of  their  species,  and  their  great  differentiation  of  structure, 
the  Cryptodira  proclaim  themselves  to  be  the  successful  group  among  the  turtles. 

Geologically  they  reach  back,  according  to  present  knowledge,  to  the  Jurassic,  being 
represented  in  the  Lower  Kimeridgian  of  Europe  by  species  of  Thalassemydidae. 

Fig.  8  represents  the  author's  present  views  regarding  the  origin  and  relationships  of  the 
various  families.    Much  remains  to  be  determined  as  to  these  relationships. 

Family  THALASSEMYDIDiE  Rijtimeyer. 

Shell  more  or  less  incompletely  ossified.  Usually  at  least  a  central  plastral  fontanel 
present;  often  also  costo-peripheral  vacuities.  Plastron  loosely  connected  with  the  carapace; 
never  closely  sutured  thereto.  Limbs  fitted  for  walking;  never  developt  as  flippers.  Skull, 
when  known,  with  the  temporal  fossae  more  or  less  rooft  over.  Triturating  surfaces  of  the 
jaws  probably  always  broad.    Neck  short. 


THALASSEMYDID^.  127 

The  present  writer  unites  what  have  usually  been  regarded  as  two  distinct  groups  of  turtles. 
For  the  one  there  have  been  employed  the  names  Thalassemydes,  Thalassemydidje,  Eury- 
sternidse,  Aciehelyidae,  for  the  other  the  family  names  Propleuridae,  Lytolomidae,  Chelonemy- 
didae.  The  first  includes  mostly  Jurassic  genera,  the  second,  Cretaceous  and  Lower  Tertiary 
forms.    Recently  a  number  of  writers  have  grouped  the  latter  in  the  family  Cheloniidae. 

The  relationships  of  the  Jurassic  genera  to  Osteopygis  and  its  kindred  appear  to  be  too 
close  to  permit  the  recognition  of  two  distinct  families.  Much  remains  to  be  learned  about  the 
skulls  of  both  groups;  but  so  far  as  they  are  known,  there  appear  to  be  no  violent  disagree- 
ments. In  all,  the  temporal  region  is  more  or  less  completely  rooft  over  by  bone,  and  the  jaws 
are,  usually  at  least,  fitted  for  crushing  hard  food.  Nevertheless,  among  the  Cheloniidae,  and 
some  other  families,  there  is  the  greatest  variation  in  respect  to  the  character  of  the  jaws. 

A  remarkable  resemblance  is  to  be  observed  between  the  shells  of  Aplax  {Eurysternum) 
and  Osteopygis.  Zittel's  figure  of  the  former  (Paiaeontographica,  xxiv,  pi.  xxvii)  shows  that 
the  hyoplastron  sent  foi-ward  a  long  process  that  came  into  contact  with  the  second  peripheral, 
just  as  in  Osteopygis.  The  hypoplastron,  too,  reacht  backward  to  the  eighth  peripheral. 
There  were,  likewise,  extensive  fontanels  enclosed  by  the  outer  ends  of  these  plastral  bones 
and  the  peripherals. 

As  indicating  on  the  part  of  writers  a  recognition  of  close  relationship  between  the  various 
elements  united  here  into  one  family,  it  may  be  recalled  that,  while  the  later  forms  have  been 
actually  incorporated  with  the  Cheloniidae,  the  Jurassic  Thalassemydidse  have  been  regarded 
as  the  source  from  which  our  living  sea-turtles  have  been  originally  derived. 

Kev  to  the  Genera  of  Thalassemydidj!;. 

A.  A  pit  in  the  second  peripheral  for  the  hyoplastron. 

a.  At  least  the  two  anterior  peripherals  suturally  joined  with  disk  of  carapace.      Rib  of 

eighth  costal  entering  a  pit  in  the  tenth  peripheral.     Shell  smooth  or  pitted Osteopygis 

AA.  No  pit,  so  far  as  known,  in  the  second  peripheral  for  hyoplastron. 

h.  Two  anterior  peripherals  of  each  side  articulating  with  the  disk  of  the  carapace. 
c.  Rib  of  eighth  costal  entering  pit  in  eleventh  peripheral ;  the  skull  and  lower 

jaw  unknown Catapleura 

bh.  None  of  the  peripherals,  so  far  as  known,  articulating  with  the  disk. 
</.  Lower  jaw  not  furnisht  with  a  beak. 

e.  Symphysis  of  lower  jaw  not  more  tlian  two-thirds  the  width  of  the 

jaws  at  the  mental  foramina Lytoloma 

ee.  Symphysis  three-fourths  the  width  given Erquehnnesui 

dd.  Lower  jaw  with  beak.     Skull  with  rooft  temporal  region.     Choan;c  in 

anterior  half  of  roof  of  mouth.     Shell  not  known Rhetechelys 

Genus  OSTEOPYGIS  Cope. 

Carapace  including  8  pairs  of  costal  plates  and  1 1  pairs  of  peripherals,  with  all  or  only  a 
part  of  the  peripherals  suturally  articulated  with  the  costals  and  the  suprapygals.  All  the 
costals  sending  the  ends  of  their  ribs  into  pits  of  the  corresponding  peripherals.  Five  vertebral 
and  4  pairs  of  costal  scutes.  The  nuchal  scute  much  wider  than  long.  Plastron  relatively 
small;  its  connection  with  the  peripherals  extensive,  reaching  from  the  second  to  the  eighth 
peripherals,  not  by  close  sutures.  Bridge  relatively  narrow.  Fontanels  in  the  midline  and  at 
the  ends  of  the  hyohypoplastral  suture.  Inframarginal  scutes  present.  Lower  jaw  with  a 
broad  and  flat  crushing  surface;  not  beakt. 
Type:  Osteopygis  emarginatus  Cope. 

This  genus  was  establisht  by  Cope  in  i868  (Proc.  Acad.  Nat.  Sci.  Phila.,  p.  i47)>  and 
had  for  its  type  O.  emarginatus.  With  it  were  included  these  species  described  at  a  later  date: 
0.  sopitus,  0.  clulydrinus,  and  0.  repandus.  In  his  next  publication  on  the  subject  (Amer. 
Naturalist,  in,  1869,  p.  88)  Cope  subdivided  the  genus,  setting  up  Propleura  with  O.  sopitus 
(  =  0.  horealts)  as  the  type.  The  two  genera  were  regarded  as  differing  in  this,  that  Osteopygis 
had  all  the  peripherals  suturally  united  with  the  disk  of  the  carapace,  while  in  Propleura  only 
the  most  anterior  peripherals  were  so  joined. 


128  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

When  this  author's  work  (Synopsis  of  the  Extinct  Batrachia,  Reptilia,  and  Aves  of  North 
America)  was  issued  in  1870,  he  described  (pp.  105-234)  both  Osteopygis  and  Propleura 
as  possessing  10  pairs  of  costal  plates.  In  the  latter  genus  he  included  only  the  species 
sopitiu,  his  repandus  being  made  the  type  of  a  new  genus  Catapleura,  and  his  chelydrinus 
being  referred  to  Osteopygis.  Cope  concluded  that  there  were  10  pairs  of  costals  because  he 
found  a  pit,  as  if  for  a  rib,  in  the  second  peripherals  and  supposed  that  he  had  found  a  pit  in 
each  of  the  eleventh  peripherals. 

In  that  portion  of  the  Synopsis  (pp.  235-252)  which  appeared  in  December,  1870,  Cope 
stated  that  as  regards  Osteopygis  the  ascription  to  it  of  10  pair  of  costals  was  an  error,  the  last 
peripheral  not  having  had  a  costal  corresponding  to  it.  As  to  Propleura,  he  adhered  to  his 
previous  opinion  that  it  possest  10  pairs  of  costals. 

In  1875  Cope  (Vert.  Cret.  Form.  West,  p.  257)  had  concluded  that  the  possession  by  Pro- 
pleura sopita  of  10  pairs  of  costals  was  very  doubtful;  and  this  species,  with  platylomus  and 
his  new  erosus  were  referred  to  Osteopygis;  while  chelydrinus  went  to  Catapleura.  Cope 
still  believed  that  Osteopygis  possest  at  least  9  pairs  of  costals. 

In  1882  (Proc.  Amer.  Philos.  Soc,  xx,  p.  144)  and  again  in  1884  (Vert.  Tert.  Form. 
West,  p.  112),  Cope  defined  Osteopygis  as  having  10  pairs  of  costals  and  Propleura  as  having 
9,  statements  directly  opposite  to  those  formerly  made. 

The  correction  of  Cope's  errors  regarding  the  number  of  costals  in  the  species  of  this  group 
was  made  by  Dr.  Baur  (Zool.  Anzeiger,  xiv,  1889,  p.  42).  He  studied  the  very  complete 
specimen  which  has  since  served  Dr.  Wieland  as  the  type  of  0.  gibhi;  and  from  this  he 
concluded  that  there  were  only  8  pairs  of  costals,  and  that  the  pit  in  the  second  peripheral 
was  for  the  reception  of  a  process  of  the  hyoplastron.  Baur  examined  also  Cope's  types  of 
the  species  of  Osteopygis,  Propleura,  and  Catapleura  and  concluded  that  there  were  no  generic 
differences  among  them. 

Baur's  results  respecting  the  number  of  costals  have  been  confirmed  by  Wieland.  Never- 
theless, Wieland  adopts  Cope's  genus  Propleura.  He  holds  that  Propleura  differs  in  having 
costo-peripheral  fontanels,  conical  rib-pits,  and  humeri  grooved  on  their  distal  ends. 

So  far  as  concerns  the  grooving  of  the  distal  articular  ends  of  the  humeri,  the  present 
writer  does  not  believe  that  enough  is  known  about  the  humeri,  not  only  of  the  species  of  the 
group  in  question  but  of  the 'living  species,  to  justify  the  use  of  the  character  proposed  by 
Wieland  to  separate  genera.  Among  species  of  Testudo  it  is  found  that  the  distal  end  of  the 
humerus  of  many,  perhaps  of  most,  is  smooth  and  rounded;  but  that  of  Testudo  orthopygia 
has  a  broad  trochlear  groove. 

Analysis  of  the  Species  of  Osteopygis. 

1.  All  the  peripherals  sutured  to  the  costals  {Osteopygis). 

A.  Posterior  peripherals  emarginate;  upper  borders  of  peripherals  not  notcht  by  the 

rib  pits;   thickness  of  outer  end  of  nuchal  about   one-eighth  its  width emarginatus 

AA .  Posterior  peripherals  not  emarginate. 

a.  Outer  end  of  nuchal  about  one-eighth  the  width  in  front ;  upper  borders  of 

peripherals  notcht  by  rib-pits gibbi 

aa.  Thickness  of  outer  end  of  nuchal  about  one-sixth  its  width  in  front;  upper 

borders  of  peripherals  not  notcht  by  rib-pits robustus 

2.  Peripherals  3  to  10  inclusive  free  from  the  peripherals  (Propleura). 

A.  Hinder  peripherals  angulated  at  end  of  sulcus chelydrinus 

A  A.  Hinder  peripherals  neither  angulated  nor  emarginate. 

a.  Rib-pits  of  eighth  and  succeeding  peripherals  flattened;  one  face  or  both  notcht 
by  rib-pits.     The  seventh  at  least  two-thirds  as  wide  as  long. 
b.  Bones  thick  and  heavy;  thickness  of  distal  end  of  first  peripheral  in  its  length 

3.5  times;    only  upper  face  of  hinder  peripherals  notcht  by  rib-pits.  ..  erosus 

bb.   Bones   thinner,  thickness  of   distal   end  of  first    peripheral    in    its    length 
4.4  times;  both  faces  of  upper  border  of  hinder  peripherals  notcht  by 

rib-pits borealis 

bbh.  Bones  thinner;  thickness  of  first  peripheral  in  its  length  4.4times;  rib-pits 

of  sixth  and  seventh  peripherals  flattened;  both  faces  of  peripherals  notcht  platylomus 
aa.  Seventh  peripheral  only  half  as  wide  as  long sopitus 


THALASSEMYDID^. 


129 


The  possession  of  conical  rib-pits  on  the  part  of  Wieland's  Propleura  borealts,  if  a  good 
generic  character,  removes  it  from  Propleura,  for  the  type  of  the  latter,  P.  sopita,  has  the  pits 
in  the  hinder  peripherals  all  flat.  This  statement  is  true  as  regards  Leidy's  type  of  his  Chelone 
sopita  and  of  Cope's  specimen,  now  regarded  as  belonging  to  Osteopygis  boreaUs. 

There  remains  therefore  only  the  presence  of  the  costo-peripheral  fontanels  to  separate 
Propleura  from  Osteopygis.  This  is  one  of  those  characters  which  can  not  be  sharply  defined 
and  which  may  be  expected  to  exhibit  in  closely  related  species  all  gradations.  We  can  not 
be  sure  that  at  any  time  a  species  may  not  be  found  in  which  a  number  of  the  lateral  peripherals 
are  joined  suturally  with  the  costals,  while  others  are  free.  Indeed,  we  can  not  be  certain  that 
in  some  of  the  described  species  of  Propleura  some  of  the  lateral  peripherals  did  not  become 
sutured  to  the  contiguous  costals.    An  aged  Colpochelys  kempt  has  a  perfectly  solid  carapace. 

Therefore,  until  better  characters  have  been  proposed  for  the  separation  of  Osteopygis 
and  Propleura,  the  present  writer  prefers  to  employ  only  the  former  name. 

Osteoygis  emarginatus  Cope. 
Telt-figs.  134-141. 

Osteopygis  emarginatus,  Cope,  Proc.  Acad.  Nat.  Sci.,  1868,  p.  147  (nom.  nud.);  Cook's  Geol.  New  Jersey, 
l868  (1869),  p.  735  (nom.  nud.);  Amer.  Naturalist,  in,  1869,  p.  89;  Ext.  Batrach.,  Reptilia,  Aves 
N.  A.,  1869,  pp.  135,  136,  235,  plate  vii,  fig.  3;  Vert.  Cret.  Form.  West,  1875,  p.  259. — Hay, 
Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  441. 

Osteopygis  platylomus,  Cope,  Ext.  Batrach.,  etc.,  p.  134,  fig.  39  in  part. 

The  two  specimens  described  by  Cope  under  this  name  are  in  the  American  Museum  of 
Natural  History.  Both  had  been  discovered  in  the  upper  bed  of  greensand  of  the  Upper 
Cretaceous,  at  Barnesboro,  Gloucester  County,  New  Jersey.     The  bones  figured  by  Cope 


Fig.  134. — Osteopygis  emarginatus.     Nuchal,  right  first  peripheral,  and  portions  of  first 
costals.     Xi     No.  1485  A.  M.  N.  H. 

c.p.  I,  First  costal  bone;   nu.p,  nuchal  bone;   nu.s,  nuchal  scute;   per.i,  first  peripheral. 

belong  to  the  second  individual  described  by  him.    This  is  in  the  American  Museum  and  bears 
the  number  1485.  , 

There  is,  however,  some  doubt  attached  to  the  peripheral  which  furnisht  Professor  Cope  s 
figure  y.  In  his  explanation  of  the  figure.  Cope  says  that  it  is  the  tenth  of  the  left  side. 
In  reality,  it  is  the  eighth.  He  states  that  the  eleventh  peripheral  of  the  right  side  is  present,  but 
it  is  not  in  the  collection.  It  seems  probable  that  the  one  he  called  the  eleventh  is  the  same  one 
he  called  the  tenth  of  the  left  side.    On  the  bone  there  has  at  some  time  been  written,  probably 


130 


FOSSIL   TURTLES   OF    NORTH    AMERICA. 


by  Cope,  "  lO  R,"  but  the  digit  on  the  right  had  evidently  been  changed  from  "  i  "  to  "o"  and 
an  "L"  to  an  "R."  Finally  ink  lines  had  been  drawn  across  these  characters  and  "8" 
written  near  by.  These  changes  indicate  that  originally  Cope  regarded  the  peripheral  as  the 
eleventh;  that  before  he  went  into  print  he  came  to  regard  the  bone  as  the  tenth;  and 
that  at  some  later  period  he  became  convinct  that  it  was  the  eighth.  The  measurements 
of  the  bone  do  not  at  all  agree  with  those  of  the  tenth  peripheral  of  Cope's  first  specimen, 
but  they  do  agree  quite  closely  with  those  of  the  tenth  of  the  second. 

Cope  (his  plate  vii,  fig.  3«)  has  represented  the  nuchal,  the  right  first  peripheral,  and  the 
proximal  end  of  both  first  costals.  These  elements  are  here  shown  in  fig.  134.  The  free 
border  of  the  nuchal  and  first  peripherals  is  obtuse.  At  the  midline,  back  from  the  free 
border,  the  thickness  is  15  mm.  The  free  border  of  the  nuchal  is  122  mm.  long,  in  a  straight 
line.  The  first  peripheral  is  65  mm.  along  the  free  border,  and  48  mm.  at  right  angles  with 
this.  It  is  17  mm.  thick  at  the  proximal  end  (fig.  135)  and  19  mm.  at  the  distal  (fig.  136). 
The  upper  surface  is  convex,  with  a  low  concavity  running  parallel  with  and  just  behind  the 
free  border. 

The  fifth  left  peripheral  (Cope,  pi.  vii,  fig.  3^,  seen  from  the  lower  and  inner  faces) 
measures  77  mm.  along  the  free  border;  58  mm.  on  the  upper  face  anteriorly,  60  mm.  poste- 
riorly; 52  mm.  across  the  inner  face  anteriorly,  48  mm.  posteriorly.  The  inner  face  contains 
a  large  pit,  circular  in  section,  for  the  end  of  the  rib  of  the  third  costal.  This  pit  occupies 
about  one-third  the  length  of  the  peripheral.  The  upper  face  is  concave  up  and  down;  the 
lower  face  is  convex.  There  was  no  sutural  connection  with  the  plastron,  but  the  upper 
border  of  the  upper  face  was  suturally  joined  to  the  costal.  Fig.  137  represents  the  anterior 
end  of  this  bone;  138  the  posterior  end.  The  hinder  end  of  the  bone  corresponds  exactly  with 
the  anterior  end  of  the  sixth  peripheral  of  0.  erosus. 


139- 


KlGS.  135-141. — Osteopygis  emarginatus.     Portions  of  shell.      Xj.     No.  1485  A.  M.  N.  H. 

135.  Section  of  proximal  end  of  first  left  peripheral.  139.  Anterior  end  of  eighth  left  peripheral. 

136.  Section  of  distal  end  of  first  left  peripheral.  140.  Hinder  end  of  eighth  left  peripheral. 

137.  Anterior  end  of  fifth  left  peripheral.  141.  Neurals. 

138.  Posterior  end  of  fifth  left  peripheral. 

The  eighth  peripheral  (Cope,  plate  vii,  fig.  y)  is  nearly  plane  above.  The  free  border  is 
mostly  missing,  but  it  had  apparently  about  the  form  shown  restored  in  Cope's  figure.  It 
was  therefore  rather  strongly  emarginated,  the  bottom  of  the  emargination  being  at  the  end  of 
the  sulcus.  The  fore-and-aft  extent  of  the  bone  at  the  middle  of  the  height  is  90  mm.;  the 
height  from  the  end  of  the  sulcus,  lOO  mm.  It  must  have  been  about  115  mm.  high  at  the  ends 
of  the  bone.  The  greatest  thickness  at  the  anterior  border  (fig.  139)  is  24  mm.;  on  the 
posterior  border  (fig.  140),  22  mm.  On  the  upper  border  the  bone  was  sutured  to  the  costal 
touching  it.  The  rib-pit,  mostly  in  the  posterior  half  of  the  inner  face,  is  30  mm.  long  and  is 
flat.    It  does  not  notch  the  upper  face. 

The  first  costals  (fig.  134)  present  only  their  proximal  halves.  The  greatest  width  fore 
and  aft  is  97  mm.  The  thickness  in  front  is  12  mm.;  posteriorly,  8  mm.  The  rib-head  was 
prominent.  In  front  of  the  ridge  descending  from  it  is  a  rough  surface  to  which  was  articulated 
the  rudimentary  first  rib. 

Among  other  fragments  of  costals  is  the  distal  two-thirds  of  one,  probably  the  fourth.  It 
is  possibly  the  one  mentioned  by  Cope  as  having  a  width  of  3  inches  and  2  lines,  this  being  the 


thalassemydidj^.  131 

width  not  far  from  the  distal  end.  Its  thickness  is  about  9  mm.  It  is  interesting,  because  it 
shows  plainly  that  it  was  articulated  suturally  with  the  contiguous  peripheral.  The  bone  is 
traverst  longitudinally  by  a  deep  sulcus.     Its  surface  is  pitted  just  like  a  costal  of  O.  erosus. 

The  neural  figured  by  Cope  (fig.  141)  is  present,  as  well  as  fragments  of  two  others.  The 
one  figured  is  55  mm.  long  and  36  mm.  wide,  deeply  notcht  in  front,  and  crost  behind  by  a 
transverse  sulcus.     It  is  probably  one  of  the  more  posterior  neurals,  the  seventh  or  the  eight. 

The  surface  of  the  anterior  bones  of  the  carapace  is  relatively  smooth.  The  fifth  peripheral 
is  somewhat  pitted,  but  the  result  probably  of  accident. 

The  nuchal  scute  measures  60  mm.  in  front,  no  mm.  behind,  and  25  mm.  fore  and  aft. 
The  first  marginal  measures  52  mm.  along  the  free  border  and  39  mm.  across  the  end  next  the 
second  marginal. 

The  first  vertebral  had  a  width  anteriorly  of  185  mm.  and  a  length  of  82  mm.  The  second 
vertebral  appears  to  have  been  about  75  mm.  wide.  No  trace  is  seen  of  the  costo-marginal 
sulcus  on  the  upper  border  of  the  fifth  peripheral;  but  doubtless  on  the  sides  of  the  shell  the 
sulci  followed  closely  the  costo-peripheral  sutures.  On  the  eighth  peripheral  the  costo-mar- 
ginal sulci  lie  from  12  mm.  to  25  mm.  below  the  upper  border  of  the  bone. 

The  femur  is  represented  by  a  portion  of  the  proximal  end;  but  the  head  and  both  trochan- 
ters are  missing.    The  shaft  has  a  diameter  of  15  mm. 

The  first  specimen  described  by  Cope  bears  the  American  Museum's  number  1344.  It 
was  an  individual  of  almost  exactly  the  same  size  as  that  regarded  as  the  type.  It  furnishes 
the  nuchal,  the  first  right  peripheral,  the  first,  second,  fourth,  fifth  left  peripherals,  the  proximal 
half  of  the  first  left  costal,  some  other  unimportant  costal  fragments,  a  part  of  the  right  hyo- 
plastron,  a  part  of  the  right  hypoplastron,  and  the  greater  part  of  both  xiphiplastra.  Cope 
mentions  additional  peripherals,  but  they  do  not  accompany  the  bones  mentioned  above,  and 
have  not  been  recognized  in  the  Cope  collection. 

That  paragraph  of  Cope's  description  which  occupies  the  upper  two-fifths  of  page  137  of 
the  Synopsis  may  be  regarded  as  a  riddle;  for  in  it  Cope  constantly  compares  the  species  he  is 
describing  with  itself.  The  explanation  appears  to  be  the  following:  With  the  specimen,  in 
Cope's  writing,  is  a  label  "Osteopygis  platylomus.  Cope,  type:  nr.  Barnesboro,  Gloucester 
Co.,  N.  J. "  At  some  subsequent  time  two  pencil  lines  have  been  drawn  through  "platylomus." 
There  can  be  no  doubt  that  the  specimen  is  the  one  Cope  describes  as  O.  emarginatus;  and 
there  can  be  little  doubt  that  the  plastral  bones  furnisht  the  right  hand  portion  of  Cope's 
fig.  39,  said  to  be  that  of  the  plastron  of  0.  platylomus.  We  may  suppose  therefore  that  at  one 
time  Cope  regarded  this  specimen  as  0.  platylomus  and  intended  to  make  it  the  type  of  the 
species;  but  coming  to  see  that  it  was  0.  emarginatus,  a  portion  of  the  manuscript  was 
transferred  to  the  latter  species  without  proper  changes. 

The  parts  common  to  this  specimen  and  the  type  of  the  species  present  no  important 
differences.  The  second  peripheral  is  75  mm.  long;  57  mm.  at  right  angles  with  the  free  border 
and  at  the  proximal  end,  and  21  mm.  thick  at  the  same  end.  The  distal  end  has  a  large  exca- 
vation for  the  process  of  the  hyoplastron.  The  fourth  peripheral  is  67  mm.  on  the  free  border, 
38  mm.  across  the  lower  face.  Most  of  the  upper  face  is  broken  away.  An  obtuse  keel 
separates  the  upper  face  from  the  lower.  The  inner  face  of  the  fifth  was  more  excavated  than 
in  the  same  bone  of  the  type;  and,  as  Cope  states,  the  pit  for  the  end  of  the  rib  is  much 
smaller. 

The  bones  belonging  to  this  specimen  which  Cope  appears  to  have  employed  in  his  fig. 39  are 
the  hyoplastron,  the  hypoplastron,  and  xiphiplastron  of  the  right  side.  The  figure  shows 
these  bones  and  those  of  the  type  of  0.  platylomus  as  seen  from  above.  A  fontanel  existed  in 
the  midline  where  it  was  crost  by  the  hyohypoplastral  suture.  Where  the  plastral  bones 
joined  along  the  midline  the  sutures  are  coarse  and  jagged.  The  xiphiplastron  sent  a  strong 
process  into  the  outer  border  of  the  hypoplastron  and  the  latter  sent  one  outside  of  this  mto  the 
xiphiplastron.  Just  in  front  of  this  exchange  of  digitations  the  hypoplastron  is  15  mm.  thick. 
At  this  level  the  hinder  lobe  of  the  plastron  was  about  165  mm.  wide.  On  the  lower  side  of  the 
hypoplastron  the  abdomino-femoral  sulcus  is  seen  in  the  position  represented  by  Cope  in  his 
figure  39.  "Crossing  the  xiphiplastron  the  femoro-anal  sulcus  falls  a  little  further  forward 
than  represented  by  Cope  in  the  figure  quoted. 

None  of  the  bones  of  this  specimen  is  pitted. 


132 


FOSSIL   TURTLES   OF    NORTH    AMERICA. 


Osteopygis  gibbi  Wieland. 
Plate  26,  fig.  1;    plate  27,  figs.  I,  z;    text-figs.  142-146. 

Osteopygis  gibbi,  Wieland,  Amer.  Jour.  Sci.  (4),  xvii,  1904,  p.  118,  plates  v-viii  and  text-figs.  3-7. 

The  type  of  this  species  is  No.  783  ot  the  Marsh  collection  of  Yale  University.  It  was 
obtained  from  the  upper  bed  of  Cretaceous  greensand,  at  Barnesboro,  Gloucester  County, 
New  Jersey,  in  1870.  It  was  originally  studied  by  Dr.  George  Baur  (Zool.  Anzeiger,  xii, 
1889,  p.  42),  who  determined  from  it  that  Cope  had  been  in  error  when  he  stated  that  the 
genus  Osteopygis  possest   10  pairs  of   costal  plates.     Fig.   I,  plate  26,  is  reproduced  from  a 

drawing  prepared  under  Baur's  direc- 
tions and  shows  the  nuchal,  the  periph- 
erals, and  the  pygal  as  seen  from  below. 
In  1904  the  specimen  was  fully  prepared 
and  the  parts  put  together  under  the 
direction  of  Dr.  Wieland.  A  number  of 
the  figures  made  by  Dr.  Wieland  are 
here  reproduced. 

The  specimen  is  the  most  complete 
that  is  known  of  any  species  of  the  family 
and  it  serves  to  give  us  a  clear  idea  of 
the  form  and  the  constituents  of  the 
shell.  It  will  be  observed  that  the  out- 
line of  the  carapace  as  restored  by  Dr. 
Baur  (plate  26,  fig.  l)  diflFers  from  that 
as  restored  by  Wieland  (text-fig.  142). 
Since,  however,  Dr.  Wieland  fitted  the 
costals  to  one  another  and  to  the  periph- 
erals, and  brought  the  plastron  into 
relation  with  the  carapace,  which  Baur 
did  not  do,  it  is  quite  certain  that  the 
later  restoration  is  the  more  accurate 
one.  It  can  hardly  be  wrong  except  in 
small  details.  Fig.  143  shows  the  shell 
from  the  side. 

In  form  the  carapace  is  elongated 
oval,  rounded  in  front  and  somewhat 
pointed  behind.  It  is  somewhat  deprest 
and  especially  the  hinder  peripherals  look 
more  upward  than  outward.  The  length 
in  a  straight  line  is  given  as  690  mm.;  the 
extreme  width,  as  about  580  mm.  The  nuchal  bone  is  127  mm.  wide  in  front  and  has  a  maximum 
width  of  145  mm.  Its  length  is  75  mm.  The  dimensions  of  the  neural  bones  are  shown  in  the  table. 
The  eighth  neural  is  apparently  followed  by  a  small  first  suprapygal.  This  is  succeeded 
by  an  irregularly  shaped  second  suprapygal,  60  mm.  long  and  162  mm.  wide.  Behind  this 
comes  the  posterior  suprapygal,  which  has  a  length  of  60  mm.  and  a  width  of  97  mm. 

All  the  peripherals  are  suturally  articulated  with  the  contiguous  ends  of  costal  bones,  except 
the  eleventh,  which  articulates  with  the  suprapygals    The  peripherals,  except  the  first,  second, 


Fig.  142. — Osteopygis  gibbi.     Carapace  of  type.     Xj. 

C.J.  I,  first  costal  bone;  m.  5.  12,  twelfth  marginal  scute;  n.  i, 
first  neural;  n.  8,  eighth  neural;  nu./>, nuchal  bune;  nu.j,nuchal 
scute;   py,  pygal;    spy.  i,  .'/>y.  2,  spy.  3,  suprapygals. 


Neural. 

I 

Length. 

Width. 

95 

4> 

2 

65 

47 

3 

65 

47 

4 

65 

43 

S 

5o± 

37 

6 

+5± 

33 

7 

45± 

30 

8 

6s± 

38± 

-Osteopygis  gibbi. 


THALASSEMYDID^. 


13.^ 


Width. 

Peripheral. 

Length. 

Thickness. 

Upper  face. 

Lower  face. 

I 

79 

60 

'7 

z 

82 

60 

21 

3 

75 

61 

4 

76 

60 

5 

80 

64 

42 

6 

85 

62 

4' 

7 

9Z 

Si 

8 

95 

T05 

26 

9 

93 

105 

>4 

10 

90 

1 1 1 

H 

II 

83 

110 

and  the  eleventh,  have  each  a  pit  in  the  inner  face  to  receive  the  end  of"  a  rib  extending  beyond 
the  costal  plate.  In  the  hinder  peripherals  these  pits  are  flattened;  also  they  produce  notches 
in  the  upper  face  of  a  number  of  the  hinder  peripherals,  as  they  do  in  O.  borealis.     This 

deficiency  in  the  upper  wall  of  some  of  the  pits 
marks  one  difference  between  this  species  and 
0.  emargtnatus,  the  type  of  the  genus.  The 
inner  face  of  the  second  peripheral  has  a  large 
pit  for  the  reception  of  the  outer  anterior  exten- 
sion of  the  hvoplastron.  The  inner  face  of  the 
third,  fourth,  fifth,  sixth,  and  seventh  periph- 
erals is  broad  and  longitudinally  excavated. 
These  bones  have  thus  three  borders,  the  outer, 
or  free  border;  the  upper  border,  which  articu- 
lates with  the  costals;  and  the  inferior  border, 
which  comes  into  contact  with  the  plastron.  In 
the  anterior  end  of  the  eighth  there  is  a  cavit\' 
into  which  the  outer  posterior  process  of  the 
hypoplastron  projects.  The  inner  face  of  the  peripherals  behind  the  eighth  becomes  narrow 
and  curves  into  the  lower  face.  Thus,  these  hinder  peripherals  are  thin  and  wedge-shaped. 
The  dimensions  of  the  peripherals  are  shown  in  the  table  herewith. 

The  acute  free  border  of  the  hinder  peripherals  may  be  traced  forward  on  the  more  anterior 
ones,  where  it  forms  a  keel  separating  the  upper  face  from  the  lower.    The  peripherals,  from 

the  seventh  to  the  eleventh  inclusive,  are  slightly  concave  on  the 
upper  surface. 

The  pygal  bone  measures  about  85  mm.  along  the  free  border 
and  has  a  height  of  about  75  mm. 

The  sulci  between  the  various  scutes  of  the  carapace  are 
rather  deeply  sunken.  The  dimensions  of  the  vertebral  scutes 
are  given  in  the  table. 

The  hinder  border  of  the  fifth  lies  on  the  posterior  supra- 
pygal.     The  supracaudals  join  along  the  midline  a  distance  of 
70  mm.  and  each  is  40  mm.  wide.    The  costo-marginal  sulci  lie  wholly  on  the  peripheral  bones, 
close  to  their  upper  margins,  except  at  the  rear,  as  just  noted. 
There  are  four  pairs  of  costal  scutes. 

The  surface  of  the  bones  of  the  carapace  is  usually  smooth;    but  in  places  there  appear 
striations,  which  are  directed  outward  and  backward.    There  are  no  pits. 


Vertebral. 

Length. 

Width. 
210 

no 

140 

120 

■33 

"5 

142 

■35 

.48 

180 

145-  '46- 

Figs.  144-146. — Osteopygis  gthhi.     Plastron  and  limb  bones  of  type. 

144.  Plastron.    Xj.    ai,  abdominal  .scute ;   on,  anal  scute;  en(,  entoplastron  ;  e/i/,  epiplastron;    /,/,  median  and 

posterior  fontanels ;   fem,  femoral  scute  ;    hyo,  hyoplastron  ;   injmf,  supposed  inframargmal  scute  ;  pec,  pec- 
toral scute;    xiph,  xiphiplastron. 

145.  Humerus,  dorsal  surface.    Xj.  146.  Femur,  dorsal  surface.    Xj. 


134 


FOSSIL  TURTLES   OF   NORTH   AMERICA. 


Relatively  to  the  carapace  the  plastron  (plate  27,  fig.  2;  text-fig.  144)  is  smaller  than  in 
Caretta  caretta.  Nevertheless,  the  connection  between  the  borders  of  the  plastron  and  the 
peripherals  is  more  extensive  than  in  the  genus  just  mentioned,  extending  from  the  second  to 
the  eighth  peripherals.  The  outer  anterior  prolongation  of  the  hyoplastron  reaches  forward 
as  far  as  does  the  anterior  lobe,  and  the  outer  posterior  prolongation  of  the  hypoplastron 
extends  backward  nearly  as  far  as  does  the  hinder  lobe.  The  hyoplastron  sends  a  process  into 
the  second  peripheral,  and  the  hypoplastron  has  its  hinder  prolongation  inserted  in  an  excava- 
tion of  the  seventh  and  eighth  peripherals.  In  the  fourth  and  sixth  peripherals  are  small 
pits  for  digitations  of  the  plastral  bones.  The  median  longitudinal  suture  is  a  coarse  one. 
There  is  a  median  fontanel  at  the  crossing  of  the  hyohypoplastral  suture  and  the  median 
longitudinal.  On  each  side,  at  the  ends  of  the  hyohypoplastral  suture,  is  another  fontanel. 
A  fourth  is  found  on  the  median  line  just  in  front  of  the  xiphiplastra. 

The  epiplastra  are  narrow  bones  which  have  a  length  of  about  85  mm.  and  a  width  of 
15  mm.  The  entoplastron  is  only  in  part  preserved.  It  appears  to  have  been  85  mm.  long 
and  59  mm.  wide. 

The  least  width  across  the  bridges  is  1 14  mm.  The  hinder  lobe  is  much  reduced,  leaving 
free  play  for  the  hinder  limbs.    The  xiphiplastra  are  185  mm.  long  and  55  mm.  wide. 

The  sulci  of  the  plastron  are  very  obscure,  but  Wieland  appears  to  have  mapt  them 
correctly.  There  were  quite  certainly  inframarginals  on  the  outer  ends  of  the  bridges.  The 
sulcus  between  the  gular  and  the  humeral  scutes  has  not  been  observed;  nor  that  between  the 
humeral  and  the  pectoral.  Wieland  calls  the  pectoral  scutes  the  humerals;  the  abdominals, 
the  pectorals;  the  femorals,  the  ventrals;  the  anals,  the  femorals.  The  abdominals  have  a 
width,  at  the  midline,  of  about  65  mm.;  the  femorals,  a  width  of  78  mm.;  the  anals,  a  width 
of  nearly  150  mm. 

Wieland  has  figured  the  humerus  (fig.  145).  The  total  length  is  145  mm.;  the  short 
diameter  of  the  flattened  shaft,  18  mm.;  the  long  diameter,  21  mm.  It  resembles  the  humerus 
of  Chelydra.  The  angle  between  the  planes  of  the  ulnar  and  radial  crests  is  obtuse.  The 
distal  end  of  the  bone  is  grooved,  as  in  some  species  of  Emydidte  and  of  Testudinidce.  The 
ectepicondylar  passage  is  a  deep  perforation.  The  femur  has  a  length  of  150  mm.,  therefore  is 
longer  than  the  humerus.  It  resembles  that  of  Chelydra,  except  that  the  distal  end  is  grooved. 
In  this  respect  too  it  differs  from  the  femur  of  0.  borealts. 

Wieland  has  described  and  figured  the  ulna,  the  tibia,  2  metatarsals,  and  I  cervical 
vertebra.    Fig.  146,  from  Wieland,  represents  the  femur. 

This  species  is  most  nearly  related  to  the  type  of  the  genus,  Osteopygts  emargtnatus 
Cope.  The  latter  differs  in  having  the  posterior  peripherals  emarginated  on  the  free  borders 
at  the  end  of  the  intermarginal  sulci,  in  not  having  the  upper  borders  notcht  so  as  to  expose 
the  end  of  the  rib,  in  having  a  shorter  first  vertebral  scute,  and  apparently  in  having  narrower 
second  and  third  vertebral  scutes.  The  type  of  O.  emarginatus  is  only  slightly  smaller  than 
the  type  of  0.  gtbbt,  the  nuchal  of  the  former  measuring  along  the  front  122  mm.;  that  of 
the  latter,  127  mm.  The  first  vertebral  scute  of  0.  emarginatus  is  close  to  82  mm.  long;  that 
of  0.  gihbi,  no  mm.  The  width  of  the  second  vertebral  of  O.  emarginatus,  at  the  anterior 
end,  is  close  to  75  mm.;  that  of  O.  gibbi,  about  102  mm. 

Osteopygis  robustus  sp.  nov. 

Figs.  i47-'5'- 

In  the  American  Museum  of  Natural  History  is  a  lot  of  bones  which  is  accompanied  by  a 
label  written  by  Professor  Cope,  stating  that  they  were  found  at  Birmingham,  New  Jersey, 
that  he  regarded  them  as  belonging  to  Osteopygis  emarginatus,  and  that  he  received  them 
November  13,  1870.  Those  bones  which  can  be  safely  regarded  as  belonging  to  one  individual 
are  the  nuchal,  the  first  and  second  peripherals  of  both  sides,  the  tenth  and  eleventh  peripherals 
of  both  sides,  the  fourth  costals  of  both  sides,  the  left  fifth,  the  left  seventh  and  the  eighth,  and 
the  proximal  end  of  the  right  eighth.  There  are  also  fragments  of  other  costals  of  unde- 
termined position.    To  this  specimen  is  given  the  number  2360. 

A  comparison  of  these  bones  with  those  of  the  types  of  0.  emarginatus  and  O.  gihbt  makes 
it  evident  that  they  belong  to  a  hitherto  undescribed  species.    The  diflFerences  will  appear  as  we 


THALASSEMYDIDiE. 


135 


progress  with  the  description.  That  which  especially  strikes  one  is  the  greater  thickness  of 
the  bones  here  described,  as  compared  with  corresponding  ones  of  0.  emarginatus  and  0.  gibhi. 
The  three  types  are  of  nearly  the  same  size.  The  dimensions  of  various  bones  are  given  in 
_the  following  table.    Except  the  length,  the  dimensions  of  each  bone  are  taken  at  the  anterior 

end.  The  thickness  of  the  nuchal  is  taken 
at  the  midline.  The  columns  headed  by 
I  belong  to  O.  emarginatus;  those  by  2, 
to  0.  gibbi;  those  by  3,  to  0.  robustus. 

The  nuchal  bone  (fig.  147)  appears 
to  have  extended  backward  further  in 
this  than  in  the  species  with  which  it  is 
compared  above.  The  hinder  portion 
of  the  bone  is  broken  away,  but  the  por- 
tion remaining  is  80  mm.  wide  antero- 
posteriorly.  The  nuchal  of  0.  emargina- 
tus measured  in  the  same  place  gives  us  70  mm.;  the  nuchal  of  O.  gibhi  has  a  length  of  75  mm. 
Fig.  148  is  a  section  at  the  articulation  between  the  nuchal  and  the  first  peripheral. 

The  upper  border  of  the  first  peripheral,  articulating  with  the  first  costal,  has  a  thickness 
of  10  mm.  (fig.  148).  The  left  second  peripheral  lacks  the  hinder  end;  and  that  of  the  right 
side  has  the  hinder  end  of  the  inner  face  so  eroded  that  it  does  not  show  the  pit  for  the  hyo- 
plastron.  These  peripherals  articulated  with  the  first  costal.  The  other  peripherals  are 
missing  to  the  ninth,  and  of  these  only  unimportant  fragments  remain.  The  tenth  and  eleventh 
(fig.  149)  are  nearly  plane  above,  or  slightly  convex.     The  rib-pits  are  flat;    and  that  of  the 


Element. 

Length . 

Height. 

Thickness. 

Nuchal  ... 

I 
izz 

»         3 
IZ7      IZ5 

I 

z 

3 

I           z 

3 

... 

IS    1    16 

zo 

Peripheral  1 

6^ 

79 

78 

48 

60 

60 

>9    i    '7 

-,o 

z 

8z 

81 

46 

60 

60 

zo       21 

^"i 

10 

90 

89 

III 

1 10 

14 

18 

II 

»1 

90 

no 

IOO± 

.  .     ;     .  . 

•9 

Pygai 

«3 

,5 

■■ 

71      68 

1 

..     ,     .. 

zo 

Fig.  147. — Osteopygts  robustus.     Nuchal  bone  and  first  peripheral  right  and  left,  of  type.      Xj. 

nu.  s,  nuchal  scute;  per.  i,  first  peripheral. 

tenth  is  rooft  over  to  the  articulation  with  the  eighth  costal  plate  with  bone  7  mm.  thick.  It  is 
possible,  but  not  probable,  that  the  ninth  peripheral  had  its  upper  border  notcht  by  the  rib- 
pit,  as  it  is  in  the  case  of  all  the  hinder  peripherals  of  O.  gibbi.  No  rib  entered  the  eleventh 
peripheral.  This  and  the  pygal  articulated  suturally  with  the  last  suprapygal.  The  upper 
sutural  border  of  the  pygal  is  13  mm.  thick.  The  free  borders  of  the  tenth  and  eleventh 
peripherals  are  acute.  Fig.  150  represents  the  front  end  of  the  tenth  peripheral.  There  are  no 
indications  of  emarginations  of  the  free  border  such  as  are  supposed  to  characterize  0.  emar- 
ginatus. The  pygal  (fig.  149)  is  notcht  somewhat  at  the  midline.  Fig.  151  is  a  section  thru 
the  middle  of  the  pygal. 

There  are  present  what  are  regarded  as  the  proximal  and  the  distal  portions  of  the  left 
fourth  costal;  the  proximal  end  of  the  right  fourth;  the  left  seventh,  lacking  most  of  the  front 
border;  the  left  eighth  entire;  and  the  proximal  end  of  the  right  eighth.  These  bones  are  all 
thick.  Where  the  suture  with  the  neurals  is  shown  the  bone  is  10  mm.  or  11  mm.  thick.  At 
the  middle  of  the  length  of  the  costals  the  sutural  edges  are  about  6  mm.  thick.  The  distal 
ends  of  costals  four  and  five  were  suturally  joined  to  the  corresponding  peripherals;  and  the 
same  is  true  of  the  seventh  and  the  eighth.  The  fourth  costal  has  a  width  of  62  mm.  at  the 
costo-vertebral  sulcus  and  70  mm.  at  the  distal  end.  The  end  of  the  rib  of  this  costal  projects 
from  near  the  front  border  of  the  distal  end,  as  it  appears  to  do,  likewise,  in  0. gibbi.  The  width 


136 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


of  the  fifth  costal  at  the  distal  end  is  jy  mm.  At  the  costo-vertebral  sulcus  the  seventh  and 
eighth  costals  (fig.  149)  are  each  39  mm.  wide.  The  eighth  is  47  mm.  wide  at  the  distal  end. 
On  the  inferior  side  of  the  eighth  costal  is  seen  the  base  of  the  small  rib-head.  Behind  this  is 
the  co-ossified  end  of  the  vestigial  tenth  rib. 

The  surface  of  the  bones  of  the  carapace  is  almost  everywhere  more  or  less  uneven.  On 
the  nuchal  and  the  anterior  peripherals  the  areas  occupied  by  the  scutes  are  tumid,  and  the 
sulci  run  in  deep  and  broad  valleys.  The  same  remarks  apply  to  the  dorsal  region  of  the 
carapace,  so  far  as  represented.    The  sulci  of  the  distal  portions  ot  the  costals  and  of  the  hinder 

peripherals  are  deeply  imprest. 
The  upper  surfaces  of  the  hinder 
peripherals  are  more  or  less  undu- 
lating. 

The  nuchal  scute  (fig.  147)  is 
smaller  than  that  of  either  0. 
emarginatus  or  0.  gtbht;  its  width 
anteriorly  being  47  mm.;  poste- 
riorly, 80  mm.;  its  fore-and-aft 
extent,  24  mm.  The  first  marginal 
is  62  mm.  along  the  front;  30  mm. 
where  it  joins  the  nuchal;  45  mm. 
where  it  joins  the  second  marginal. 
On  the  tenth  peripheral  the  costo- 
marginal  sulcus  runs  30  mm. 
below  the  upper  border  of  the 
bone.  At  the  midline  behind,  the 
sulcus  crosses  on  the  hinder  supra- 
pygal. 

The  anterior  vertebral  scute 
had  a  width  of  about  200  mm. 
On  the  fourth  costal  the  costo- 
vertebral sulcus  crosses  the  bone 
at  a  distance  of  about  44  mm. 
from  the  neural  border.  Esti- 
mating the  width  of  the  neural  at 
45  mm.  the  width  of  the  third  ver- 
tebral would  be  about  135  mm. 
The  fourth  vertebral,  at  the  ante- 
rior border  of  the  seventh  costal, 
appears  to  have  been  about  100 
mm.  wide.    That  of  0.  gtbbi  was 


Figs,  li 


151 

-151 


-Osteopygis  robustus.     Costals,  peripherals, 
and  pygal  of  type. 

148.  Section  at  proximal  end  of  first  peripheraL     Xj. 

149.  Right  seventh  and  eighth  costals,  hinder  peripherals,  and  pvgal.    xj. 

150.  Section  of  anterior  end  of  tenth  peripheral.     Xj. 

151.  Section  along  middle  of  pygal.     Xj. 


about  135  mm.  wide.    The  fifth  vertebral  had  a  width  posteriorly  of  190  mm.    Its  length  was 
close  to  155  mm. 

On  account  of  the  common  feature  of  sutural  union  of  all  the  peripherals  with  the  costals, 
this  species  needs  comparison  only  with  0.  emarginatus  and  O.  gibhi,  and  such  comparisons 
have  already  been  made. 

Osteopygis  chelydrinus  Cope. 

Plate  23,  figs.  4-7;    plate  28,  figs.  1-4;   teit-figs.  152-154. 

Osteopygis  chelydrinus,  CoPE,  Proc.  Acad.  Nat.  Sci.  Phila.  1868,  p.  147  (nom.  nud.);  Geol.  New  Jersey, 
Cook,  1869,  Append.,  p.  735  (nom.  nud.);  Amer.  Naturalist,  in,  1869,  p.  89;  Ext.  Batrach.. 
Reptilia,  Aves  N.  A.,  1869,  pp.  135,  138,  plate  vii,  fig.  8.— Hay,  Bibliog.  and  Cat.  Foss.  Vert. 
N.  A.,  1902,  p.  441. 

Catapleura  chelydrina.  Cope,  Vert.  Cret.  Form.  West,  1875,  p.  259. 

In  his  Synopsis  of  the  Extinct  Batrachia,  Reptilia,  and  Aves  of  North  America,  Professor 
Cope  stated  that  this  species  was  represented  by  "only  10  marginal  plates  more  or  less  perfect 
and  some  costals";    also  that  the  species  was  referred  to  the  genus  Osteopygis  because  the 


THALASSEMYDID^. 


137 


"anterior  rib-bearing  marginal  bone  has  been  united  with  the  middle  disk  by  suture."  In  the 
Vertebrata  of  the  Cretaceous  Formations  of  the  West  he  says  that  the  reference  of  the  species 
to  Cataphura  is  not  final,  "  as  the  anterior  costals  and  marginals  are  not  known.  " 

Of  Cope's  type  only  a  single  bone  was  figured,  the  peripheral  which  he  regarded  as  doubt- 
fully the  tenth  of  the  right  side.  In  the  Cope  collection  of  fossil  reptiles  in  the  American 
Museum  of  Natural  History  this  figured  bone  is  found  (plate  23,  figs.  4,  5;  text-fig.  152).  It  is 
accompanied  by  a  number  of  other  bones,  some  of  which  are  markt  in  such  a  way  that  it  is 
evident  that  Cope  intended  to  figure  them;  besides  other  bones  which  probably  do  not  belong 
to  the  species.  It  is  evident  that  several  of  the  bones  belonging  to  the  type  have  been  lost, 
while  it  is  probable  that  a  few  of  other  species  have  become  mingled  with  it.  It  is  certain, 
therefore,  that  our  future  identification  of  the  species  in  new  materials  must  depend  princi- 
pally on  the  figured  peripheral.  The  catalog  number  is  1131.  Cope's  label  shows  that  the 
type  came  from  Barnesboro,  New  Jersey. 

It  is  evident  that  the  bone  in  question  does  not  belong  to  the  right  side.  Usually  in  the 
related  species  the  pit  for  the  rib  lies  nearer  the  hinder  end  of  the  bone  and  the  sulcus  reaches  the 
upper  border  in  front  of  the  pit;  but  if  this  bone  is  assigned  to  the  right  side,  this  pit  will  lie 
nearer  the  front  end  and  the  sulcus  will  fall  behind  the  pit.  The  bone  appears  to  be  the  seventh 
of  the  left  side.  It  resembles  closely  the  seventh  of  a  specimen  of  O.  horealis,  but  with  specific 
differences. 

Cope  has  given  the  length  and  breadth  of  this  bone  as  being  respectively  2  inches  9.3  lines 
(70  mm.)  and  3  inches  2  lines  (80  mm.),  by  length  meaning  evidently  the  distance  from  the 
suture  with  the  bone  in  front  to  that  with  the  bone  behind,  and  by  width  the  distance  from  the 
costal  border  to  the  free  border.    These  dimensions  will  vary  somewhat  with  the  points  selected 

[52. 


Figs.  152-154. — Osteopygis  chelydrinus.     Sections  of  peripherals  of  type.     Xj. 

151.  Section  of  seventh  peripheral.  153.  Section  along  intermarginal  sulcus  of  second  left  peripheral. 

154.  Section  at  front  of  third  peripheral. 

on  the  borders.  The  free  border  of  the  bone  originally  measured  at  least  75  mm.;  the 
upper  border  now  measures  53  mm.;  and  the  anterior  border  80  mm.  Cope  states  that 
these  peripherals  are  remarkable  for  their  shortness,  but  a  careful  comparison  hardly  confirms 
this  statement.  A  more  certain  character  appears  to  be  found  in  the  thickness  of  the  bone. 
The  thickness  of  the  end  regarded  by  the  present  writer  as  the  anterior  is  slightly  more  than 
23  mm.;  that  of  the  other  end  is  19  mm.  This  is  considerably  more  than  the  thickness  of  even 
the  eighth  peripheral  of  any  known  species,  regard  being  had  for  the  other  dimensions. 

Another  character  has  been  noted  by  Cope,  the  angulation  of  the  free  border,  at  the  end 
of  the  epidermal  sulcus.  The  angle  included  between  the  two  portions  of  this  border  is  about 
130°.  In  other  species  the  border  is  nearly  straight  or  slightly  concave  where  met  by  the 
sulcus.  Usually  in  turtles,  when  the  border  of  the  carapace  is  notcht,  the  sulcus  ends  at  the 
notch.  Whether  or  not  the  angulation  of  the  border  is  found  in  all  of  the  posterior  peripherals 
we  have  now  no  means  of  determining;  but  in  all  probability  all  were  angulated. 

The  pit  for  the  extremity  of  the  rib  is  elliptical  in  section  and  29  mm.  deep.  The  horizontal 
diameter  is  15  mm.;  the  perpendicular,  11  mm. 

The  bone  may  be  regarded  as  having  three  faces,  an  upper,  a  lower,  and  an  inner.  The 
upper  is  slightly  concave  along  a  line  from  the  costal  to  the  free  border.  The  epidermal 
sulcus  is  broad,  but  rather  shallow.  The  sulci  between  the  marginal  scutes  and  the  adjacent 
costal  scutes  appear  to  have  run  along  close  to  the  costal  border.  The  lower  face  is  consid- 
erably convex  along  a  line  from  the  free  to  the  costal  border.  On  this  face  there  is  a  broad 
shallow  sulcus,  corresponding  to  the  one  above.  The  inner  face  contains  the  rib-pit.  This 
face  is  concave  and  irregular,  with  the  upper  portion  overhanging  the  lower.  The  bone  did 
not  form  a  sutural  connection  with  the  border  of  the  first  costal  plate. 


13^8  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

The  second  peripheral  of  the  left  side  (plate  23,  figs.  6,  7;  text-fig.  153)  measures  64  mm. 
along  the  free  border  and  has  a  minimum  width  of  45  mm.  From  the  thin  costal  border  the 
bone  thickens  rapidly  on  the  lower  side  until  a  thickness  of  16  mm.  is  attained  at  the  proximal 
end  of  the  bone  and  of  19  mm.  at  the  distal  end.  The  inner  half  of  the  lower  surface  is  a  little 
concave;  the  outer  half  very  convex  and  rising  to  meet  the  upper  surface.  The  anterior  half 
of  this  face  looks  forward.  The  distal  end  of  the  lower  surface  is  deeply  excavated  for  the 
outer  anterior  angle  of  the  hyoplastron.  There  can  be  little  doubt,  it  is  believed,  that  this  is 
the  peripheral  whose  length  and  breadth  Professor  Cope  has  given  respectively  as  2  inches 
6  lines  and  i  inch  9  lines.    It  was  evidently  suturally  united  with  the  first  costal  plate. 

The  third  peripheral  (plate  28,  figs.  I,  2;  text-fig.  154)  of  the  right  side  is  present.  It  has 
an  extent  of  61  mm.  along  the  free  margin  and  42  mm.  at  right  angles  with  this.  It  presents 
three  faces,  an  upper,  an  inner,  and  a  lower.  The  inner  face  is  concave  and  is  to  a  great  extent 
occupied  by  an  excavation  for  the  reception  of  the  rib  of  the  first  costal  plate.  Its  width  is  42 
mm.  where  widest.    It  is  separated  from  the  lower  face  by  a  sharp  ridge. 

The  upper  face  is  nearly  plane  except  in  front  where  it  rises  to  the  summit  of  a  ridge, 
on  which  it  joins  the  lower  face.  A  sulcus  crosses  this  face  nearer  the  proximal  end.  Its  hinder 
border  is  grooved  by  the  sulcus  between  the  marginal  and  the  first  costal  scute.  The  maximum 
width  of  this  face  is  34  mm.  The  lower  face  is  quite  convex  vertically,  the  upper  portion  of  it 
looking  upward  and  forward,  the  remainder  downward  and  forward.  Its  width  is  23  mm. 
What  distinguishes  these  anterior  peripherals  especially  is  the  carina  where  the  upper  face 
meets  the  lower. 

Accompanying  the  bones  above  described  is  the  lower  jaw  of  a  turtle,  consisting  of  the 
united  dentaries  (plate  28,  figs.  3,  4).  This  has  written  on  it,  doubtless  by  Professor  Cope,  the 
name  "chelydrinus. "  It  is  hardly  conceivable  that  he  would  not  have  mentioned  this  jaw  had 
it  been  present  when  he  described  the  other  bones.  It  is  difficult  to  understand  why  he  should 
have  referred  it  to  this  genus  and  species  without  some  good  reason,  when  it  would  naturall}' 
have  been  placed  in  his  genus  Lytoloma.  It  is  possible  that  he  discovered  after  his  description 
had  been  publisht  that  it  belonged  with  the  type  of  0.  chelydrinus,  yet  he  does  not  mention 
the  lower  jaw  in  his  reference  of  the  species  to  Catapleura  in  1875;  but  he  does  give,  under 
the  genus  Osteopygis,  a  description  of  the  lower  jaw,  which  description  might  have  been  based 
on  the  jaw  now  under  consideration;  and  no  other  jaw  is  known  which  has  been  referred  to 
Osteopygis.  The  matrix  clinging  to  the  jaw  is  exactly  like  that  on  the  peripherals.  The 
matter  is  very  obscure. 

This  jaw  resembles  that  of  Lytoloma  angusta,  but  there  are  at  least  specific  differences. 
Figures  of  it  are  here  presented.  In  the  jaw  called  "chelydrinus"  the  outline  is  almost  that  of 
a  semicircle  whose  center  lies  a  little  behind  the  posterior  end  of  the  symphysis  and  whose 
radius  is  38  mm.  In  Lytoloma  angusta  the  outlines  of  the  jaw  run  in  nearly  direct  lines  from 
the  front  of  the  masseteric  fossa  to  near  the  tip  of  the  jaw.  In  the  jaw  "chelydrinus"  a  line 
joining  the  mental  foramen,  lying  in  the  front  of  the  left  masseteric  fossa,  with  that  of  the 
right  side  tails  at  or  a  little  behind  the  posterior  end  of  the  symphysis.  In  the  type  of  Lyto- 
loma angusta  the  same  line  falls  in  front  of  this  end  of  the  symphysis  a  distance  equal  to 
one-sixth  the  whole  length  of  the  symphysis.  In  "chelydrinus"  the  symphysis  forms  47  per 
cent,  of  the  width  of  the  jaws  at  the  front  of  the  masseteric  fossae;  in  Lytoloma,  58  per  cent. 
It  is  quite  evident,  therefore,  that  the  jaw  labeled  "chelydrinus"  represents  a  species  distinct 
from  Lytoloma  angusta.  It  differs  fully  as  much  from  the  jaw  figured  by  Wieland  under  the 
name  Lytoloma  angusta,  here  described   as   Lytoloma  wielandi. 

Osteopygis  erosus  Cope. 
Plate  26,  Sg.  2;   text-figs.  155-162. 

Osteopygis  erosus.  Cope,  Vert.  Cret.  Form.  West,  1875,  p.  258. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.A., 
1902,  p.  441.  J 

The  type  of  Cope's  Osteopygis  erosus  is  now  in  the  American  Museum  of  Natural  History 
and  bears  the  number  1 130.  The  specimen  appears  to  have  been  discovered  in  the  upper  bed 
of  Cretaceous  greensand,  at  Barnesboro,  New  Jersey,  in  1869.  It  was  probably  found  too 
late  for  inclusion  in  the  monograph  of  1869  and  was  reserved  for  publication  until  1875.    The 


THALASSEMYDID^. 


139 


Fig.  155. — Osteopygis  i-rosus. 

First  and  second  peripherals  and  first  costal  of  type. 
X§.     First  peripheral  at  the  right. 


type  specimen  comprises  all  the  peripherals  of  the  left  side,  except  the  third,  fourth,  fifth,  and 
eleventh;  the  second,  fourth,  eleventh  and  half  of  the  ninth  of  the  right  side;  the  first  left 
costal,  lacking  the  distal  end;  the  distal  end  of  the  first  right  costal,  and  many  fragments  of 
other  costals;  two  neurals  and  a  portion  of  a  suprapygal;  some  fragments  of  the  plastron; 
and  two  vertebrae.    Cope  mentions  five  vertebrae. 

An  estimate,  based  on  the  dimensions  of  the  peripherals,  shows  that  the  carapace  was 

probably  slightly  shorter  than  that  of  the  type  of 
O.  gibbi;  that  is,  it  was  about  740  mm.  long  in  a 
straight  line. 

Professor  Cope  stated  that  this  species  is 
abundant  in  the  upper  bed  of  Cretaceous  green- 
sand  at  several  localities  in  New  Jersey,  but  the 
present  writer  knows  of  but  one  other  specimen. 
The  nuchal  bone  is  missing,  but  its  form  and 
proportions  were  probably  similar  to  those  of  the 
nuchal  of  0.  emargmatus.  The  following  table 
presents  the  dimensions  of  the  peripherals  (plate 
26,  fig.  2;  text  fig.  155).  The  length  is  taken 
along  the  free  border.  The  height  is  the  distance 
at  the  anterior  end  of  the  bone,  from  the  free 
border  to  the  costal  border.  The  thickness  is  the 
greatest  taken  at  the  anterior  end  of  the  periph- 
eral. Where  a  definite  inner  face  presents  itself, 
as  from  peripherals  4  to  8,  the  thickness  is 
replaced  by  the  dimensions  of  these  faces.  The 
dimensions  of  the  hinder  end  of  any  bone  are  the  same  as  the  dimensions  of  the  front  end  of 
the  succeeding  bone. 

The  free  borders  of  the  first  (fig.  156)  and  second  (fig.  157)  peripherals  are  thick  and 
obtuse.  On  the  fourth  there  is  a  subacute,  slightly  upturned  free  edge,  which  may  be  traced 
forward  as  an  obtuse  keel,  even  to  the  first  peripheral.  On  the  fourth  peripheral  (fig.  158) 
the  upper  and  the  lower  faces  form  an  angle  with  each  other  greater  than  a  right  angle;  but  on 
the  sixth  (fig.  159)  this  is  already  less  than  a  right  angle;   and  more  posteriorly  the  two  faces 

become  more  nearly  parallel  (figs.  160, 
161).  The  upper  faces  of  the  four  ante- 
rior peripherals  are  irregularly  convex; 
those  of  the  sixth  and  seventh  are  some- 
what concave;  those  of  the  others  are 
nearly  plane. 

In  the  hinder  end  of  the  second 
peripheral  (fig.  157)  is  a  deep  pit  for  the 
anterior  prolongation  of  the  hyoplas- 
tron.  Cope  thought  that  this  pit  was 
for  the  rib-end  of  the  first  costal.  The 
pits  in  the  greater  number  of  the  periph- 
erals are  circular  in  section.  Those  of 
the  ninth,  tenth,  and  eleventh  are  flat- 
tened. In  the  last^mentioned  cases  the  pits  produce  notches  in  the  upper  faces  of  the  periph- 
erals. The  anterior  end  of  the  inner  face  of  the  eighth  peripheral  is  deeply  excavated  for  the 
posterior  outer  angle  of  the  hypoplastron.  The  inner  face  of  the  seventh  is  considerably 
excavated  for  the  same  purpose.  Several  shallow  pits  appear  along  the  lower  borders  of  the 
inner  face  of  the  sixth  and  seventh  peripherals  for  digitations  of  the  plastron.  There  was  no  pit 
in  the  eleventh  peripheral.  This  bone  had  a  thickness  of  18  mm.  where  it  joined  the  pygal. 
As  regards  the  connection  of  the  peripherals  with  the  costals,  we  appear  to  have  the  fol- 
lowing: The  first  and  second  peripherals  were  closely  sutured  with  the  first  costal.  The  distal 
end  of  this  costal  shows  that  at  least  the  anterior  half  of  the  third  peripheral  was  sutured  with 
it.    The  anterior  end  of  the  upper  border  of  the  fourth  costal  is  smooth;   the  posterior  two- 


Peripheral. 

Length . 

Height. 

Thickness. 

Width.               ' 

I 

83 

61 

Lower  face. 

Inner  face. 

21 

1 

8i 

62 

^3 

3 

5' 

3' 

4 

78 

53 

?8 

63 

5 

64 

43 

68 

6 

83 

65  ± 

57 

47± 

7 

85 

76 

57 

46 

8 

94 

9^ 

80 

3' 

9 

98± 

IOO± 

18 

10 

95 

97 

•7 

■■ 

II 

90± 

io5± 

'7 



140 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


thirds  is  rough,  indicating  sutural  union  with  the  second  costal.  Probably  the  sixth  peripheral 
was  free  from  union  with  a  costal;  also  the  seventh.  The  hinder  portion  of  the  border  of 
the  eighth  peripheral  is  rough,  as  if  it  had  formed  a  suture  with  the  contiguous  costal.  The 
upper  borders  of  the  succeeding  two  peripherals  are  broken  away,  so  that  we  can  not  determine 
their  mode  of  connection  with  the  costals.  The  eleventh  peripheral  articulated  suturally  with 
the  suprapygals. 

The  first  costal  bone  (fig.  155)  has  an  extreme  width  of  104  mm.  The  outer  end  of  its 
rib  was  inserted  in  the  third  peripheral.  In  front,  where  it  articulated  with  the  nuchal,  it  is 
10  mm.  thick  and  the  suture  is  beveled  in  a  manner  to  show  that  the  nuchal  slightly  overlapt 
the  costal.  The  hinder  border  is  9  mm.  thick.  Another  costal  has  a  width  of  72  mm.  and  a 
thickness  of  10  mm.    The  rib  is  not  conspicuous  on  the  under  side. 

The  two  neural  bones  are  probably  the  third  and  fourth  (fig.  162).  Measured  along  the 
midline  the  bone  anterior  is  84  mm.  long,  while  the  width  is  42  mm.  The  anterior  end  is 
narrowly  notcht  for  the  reception  of  the  preceding  neural.  There  is  no  definite  angle  between 
the  antero-lateral  and  the  postero-lateral  sides.  The  other  neural  is  61  mm.  long  and  40  mm. 
wide. 

The  sulci  which  mark  the  boundaries  of  the  horny  scutes  are  extremely  distinct,  becoming 
sometimes  deep  and  broad.    The  outer  end  of  the  first  marginal  is  46  mm.  wide.    The  second 


Figs.  156-162. — Osteopygis  erosus.     Portions  of  shell  of  type.     No.  1 130  A.  M.  N.  H. 


156.  Section  of  first  periplieral.      X5. 

157.  Hinder  end  of  second  peripheral. 

pit  for  process  of  hyoplastron. 

158.  Section  of  fourth  peripheral.     X| 


159.  Section  at  anterior  end  of  sixth  peripheral.     X3. 
Xjf.    Shows  160.  Section  at  middleof  length  of  eighth  peripheral.  Xjf. 

161.  Hinder  end  of  tenth  peripheral.     XJJ. 

162.  Two  neurals.      xj. 


extends  from  the  free  border  55  mm.;  the  third,  41  mm.  Behind  this,  the  costo-marginal 
sulci  run  along  on  the  upper  borders  of  the  peripherals.  From  the  upper  borders  of  the 
eleventh  peripheral  the  sulcus  crost  on  the  last  suprapygal,  not  coming  into  contact  with  the 
pygal.  The  first  vertebral  scute  appears  to  have  been  as  in  0.  emarginatus.  Its  width  can 
not  be  determined. 

All  the  bones  of  the  carapace  are  more  or  less  rough  and  uneven,  but  that  which  especially 
distinguishes  them  is  the  presence  of  numerous  pits.  These  vary  in  size,  depth,  and  distri- 
bution. The  average  diameter  is  about  5  mm.  These  pits  are  relatively  few  on  the  anterior 
portion  of  the  carapace.  They  are  numerous  on  the  costals,  and  present  commonly  on  the 
peripherals  (plate  26,  fig.  2). 

The  fragments  of  the  plastron  furnish  no  useful  information, 

Accompanying  the  bones  are  a  scapula  and  an  ilium.  The  upper  end  of  the  scapula 
and  the  distal  end  of  the  procoracoid  process  are  broken  off.  The  remainder  of  the  bone 
resembles  the  same  bone  in  Caretta  caretta.  The  ilium  is  broader  and  flatter  above  than  in  the 
genus  just  named. 


THALASSEMYDID^.  I4I 

Osteopygis  borealis  (Wieland). 

Plate  26,  fig.  3;    text-figs.  163-171. 

Osteopygis  sopita, CoPE,  Proc.  Acad.  Nat.  Sci.  Phila.  1868,  p.  147;  Vert.Cret.  Form.  West,  1875,  p.  258. — 

Hay,  Bibliog.  and  Cat.  Koss.  Vert.  N.  A.,  1902,  p.  441. 
Propleura  sopita,  CoPE,  Cook's  Geol.  New  Jersey,  1868  (1869),  p.  735;  Amer.  Naturalist,  III,  1869,  p.  88; 

Ext.  Batrach.,  Rept.,  Aves  N.  A.,  1869,  pp.  140,  235,  p.  vii,  figs.  4-7,  text-fig.  39. 
Propleura  borealis,  Wieland,  Atner.  Jour.  Sci.,  (4)  xvii,  1904,  p.  129,  pi.  ix;    ihid,  xviii,  1904,  p.  190, 

fig-  4- 

Under  Osteopygis  sopitus  the  writer  has  presented  his  reasons  tor  concluding  that  Cope 
erred  when  he  referred  to  that  species  the  specimen  of  Osteopygis  which  he  described  in  his 
Extinct  Batrachia,  etc.,  p.  140,  plate  vii,  figs.  4-7. 

The  type  of  Wieland's  Propleura  borealis  is  No.  778  of  the  Marsh  collection,  in  the  Yale 
University  museum.    It  was  obtained  in  1870,  from  the  upper  bed  of  greensand,  near  Horners- 


FlG.  162.— Osteopygis  borealis.     The  humerus,  and  parts  of  carapace,  plastron  and  pelvis.     X  J. 

c  p  I,  c.«.  2,  etc.,  costal  plates;  Aum,  humerus  ;  Ajo,  hyoplastron  ;  A>/>o,  hypoplastron  ;  ;7,  ilium  ;  mcA,  ischium; 
n.l,n,2,  first  and  second  neurals;  nu.p,  nuchal  plate;  /.«*,  pubis;  xifih,  x.phiplastron.  I,  2,  3,  etc.,  right 
and  left  peripherals. 

town,  Monmouth  County,  New  Jersey.  It  furnishes  the  nuchal  and  the  first  and  the  second 
neural;  the  second,  third,  fifth,  sixth,  and  seventh  right  peripherals;  the  first,  second, 
third,  fifth,  and  sixth  left  peripherals;  the  first,  second,  fourth,  and  filth  right  costals;  the  first 
and  second  left  costals;  the  right  hyoplastron  and  hypoplastron;  both  xiphiplastra;  the 
left  humerus;  the  left  pubis  and  ilium;  and  both  iha.  These  bones  are  in  a  fine  state  of 
preservation. 


142 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


Wieland  suggested  that  his  type  might  prove  to  belong  to  0.  erosus.  However,  the  latter 
differs  in  having  thicker  bones  and  a  longer  nuchal.  To  illustrate  this  statement  we  will 
consider  the  seventh  peripheral.  The  length  of  this  is  88  mm.,  just  three-fourths  that  of  the 
same  bone  in  the  type  of  borealis,  yet  the  thickness  of  the  inner  face  is  47  mm.— 7  mm.  more 
than  in  the  latter  species.    This  is  too  great  to  be  due  to  age  or  individual  variation.    The 

length  of  the  nuchal  in  borealis  is  90 
mm.  This  bone  is  not  present  in  the 
type  of  erosus,  but  the  left  peripheral 
and  first  costal  show  that  it  extended 
backward  at  least  90  mm.,  and  it  cer- 
tainly was  still  longer.  If  the  animal 
had  grown  to  be  a  fifth  or  a  fourth 
larger  the  nuchal  would  have  been 
much  more  than  90  mm.  in  length. 
The  anterior  peripherals  of  O.  erosus 
are  higher  than  those  of  the  type  of 
borealis,  altho  the  latter  belonged  to  a  considerably  larger  individual. 

On  comparing  the  bones  of  borealis  with  those  of  Cope's  supposed  sopitus  in  the 
American  Museum  of  Natural  History  no  important  diiferences  are  observed.  The  nuchals 
agree.  The  surface  of  borealis  is  marked  by  pits  resembling  rain-drop  impressions;  but  the 
surface  of  Cope's  specimen  is  so  markt  to  some  degree,  and  a  larger  specimen  referred  to  the 
species  has  such  impressions  in  abundance.  Some  differences  do  appear,  when  careful  compari- 
sons are  made  among  the  measurements  of  the  peripherals,  but  these  fall  within  a  few 
millimeters.  Greater  differences  may  be  observed  between  other  specimens  which  are  regarded 
as  belonging  to  0.  borealis.  Figures  and  measurements  are  presented  above  of  various  parts 
of  Wieland's  specimen.  A  portion  of  these  are  taken  from  Dr.  Wieland's  paper,  but  most 
of  them  have  been  kindly  furnisht  me  by  the  author. 

Fig.  163  is  redrawn  from  Wieland's  figure  in  the  American  Journal  of  Science  and  reduced 
by  one-fourth  making  the  figures  one-eighth  the  size  of  nature. 


PeripheraL 

Length. 

Height. 

Thickness. 

Width. 

Lower  face. 

Upper  face. 

2 
3 
4 
5 
6 

7 

103 
95 

75 

90 
104 
..0 

60 
60 

45 

58 
68 
80 

»3 
28 

40 

40 
60 

45 

'5 

50 

*°        1 

Figs.  164-168. — Osteopygis  borealis.     Peripherals  of  type.      Xj. 


164.  First  left  peripheral,  with  section  (164/3)  of  the 

proximal  end.    In  the  section  the  upper  surface 
is  directed  toward  the  left. 

165.  Anterior  end  of  third  peripheral. 


166.  Anterior  end  of  fifth  peripheral. 

167.  Anterior  end  of  sixth  peripheral. 

168.  Anterior  end  of  seventh  peripheral. 


Fig.  164  presents  the  first  left  peripheral  from  above,  together  with  a  view  of  the  end 
which  joins  the  nuchal  bone;  figs.  165,  166,  167,  and  168  represent  the  anterior  ends  respect- 
ively of  the  third,  fifth,  sixth,  and  seventh  right  peripherals. 

The  length  of  the  first  neural  is  102  mm.;  its  greatest  width  is  55  mm.  The  first  costal 
has  a  maximum  width  of  about  120  mm.  The  second  is  90  mm.  wide  at  the  costo-vertebral 
sulcus.    The  first  vertebral  scute  is  about  285  mm.  wide;  the  second,  about  180  mm. 

The  plastron  (fig.  163)  in  general  resembles  that  of  0.  gibbi;  but  the  fontanels  appear  to 
have  been  larger  and  the  bridge  was  wider.  The  latter  has  a  width  of  138  mm.  The  whole 
plastron  had  a  width,  taken  across  the  hypoplastra,  of  about  520  mm.  The  hyoplastron 
extended  forward  from  the  hyohypoplastral  suture  138  mm. 


THALASSEMYDID^. 


143 


The  humerus  (fig.  163,  hum)  has  an  extreme  length  of  170  mm.  The  shaft  dorso-ventrally 
is  17  mm.  thick.  The  smooth  rounded  end  is  54  mm.  wide.  The  ulnar  crest  rises  ahove  the 
head.  Between  the  plane  of  the  two  proximal  processes  the  angle  is  obtuse. 
The  pelvis  (fig.  163  11,  isch,  pub)  resembles  in  general  that  of  Chelydra. 
The  specimen  referred  to  above  as  having  been  described  by  Cope  as  Osteopygis  sopitus 
is  now  in  the  American  Museum  of  Natural  History  and  has  the  number  2351.  It  consists 
of  peripherals  one  to  four,  seven,  eight,  and  ten,  of  the  right  side;  peripherals  one,  three  to 
five,  seven,  eight,  and  ten,  of  the  left;  the  nuchal,  the  proximal  portions  of  costals  one  to 
four  of  the  left  side;  one  nearly  complete  costal,  perhaps  the  third  of  the  right  side;  many 
fragments  of  other  costals;  a  number  of  plastral  bones;  parts  of  both  humeri;  and  a  complete 
left  femur. 

Cope  has,  from  this  specimen,  produced  a  figured  restoration  of  the  carapace  (Ext.  Batr. 
Rept.,  etc.,  p.  139,  fig.  39).  This  is  represented  as  having  10  pairs  of  costal  plates  and  a  corre- 
sponding number  of  neural  bones.  It  is  difficult  to  understand  how  that  author  could  suppose 
that  the  rib  of  the  first  costal  could  extend  far  enough  forward  to  enter  the  pit  in  the  second 
peripheral.  Evidently  he  saw  no  other  possible  use  for  the  pit.  The  eleventh  peripheral  is 
not  present.  On  the  tenth  is  found  the  number  "10,"  written  in  ink;  but  at  that  time  the 
right  hand  digit  "o"  was  written  upon  a  "i."  Altho  on  page  235  of  the  work  cited.  Cope 
concluded  that  the  genus  Osteopygis  had  only  nine  pairs  of  costals,  he  maintained,  from  exami- 
nation of  the  present  specimen,  that  Propleura  had  ten  pairs.  Nevertheless,  in  his  Vertebrata 
of  the  Tertiary,  publisht  in  1884,  he  stated  that  Osteopygis  had  10  pairs  and  Propleura  9  pairs. 

Cope  figured  a  part  of  the  nuchal, 
the  first  left  peripheral,  and  a  part  of 
the  first  left  costal.  They  are  refigured 
(fig.  169,  p.  145),  with  the  addition  of 
fragments  overlookt  by  Cope.  The 
front  of  the  carapace,  along  the  nuchal, 
was  somewhat  concave.  The  free  bor- 
ders of  the  nuchal  and  the  anterior  per- 
ipherals are  obtuse  and  thick.  At  the 
midline  the  nuchal  is  10  mm.  thick. 
The  fore-and-aft  length  of  the  nuchal 
is  78  mm. ;  its  width  along  the  free  bor- 
der was  close  to  120  mm.  The  border 
which  joined  the  first  neural  is  only  5 
mm.  thick.  The  table  gives  the  dimensions  of  the  peripherals,  the  measurements,  except 
the  lengths,  being  taken  at  the  anterior  ends.  In  a  few  cases  a  dimension  has  been  taken 
from  the  contiguous  end  of  the  peripheral  in  front. 

The  first  peripheral  was  suturally  joined  to  the  first  costal;  probably  also  the  second,  but 
the  border  is  missing.  It  is  probable  that  all  the  other  peripherals  to  the  eleventh  were  free 
from  the  contiguous  costals,  but  the  upper  border  of  the  fifth  has  some  appearance  of  having 
formed  a  suture.  The  upper  faces  of  the  anterior  peripherals  are  nearly  plane.  Beginning  with 
the  fifth,  the  upper  faces  are  more  or  less  concave  from  the  free  edge  to  the  costal  border.  The 
hinder  peripherals  have  a  thin  acute  border  and  this  may  be  traced  foi-ward,  but  becoming  less 
acute,  to  the  first  peripheral.  In  the  hinder  end  of  the  second  peripheral,  in  the  inner  face,  is  a 
pit,  like  a  deep  thumb  impression,  for  the  anterior  prolongation  of  the  hyoplastron.  The  other 
peripherals  have  each  a  pit  for  the  end  of  the  corresponding  rib.  They  are  at  the  middle  of  the 
length  of  the  inner  face.  Most  of  them  are  circular  in  section,  but  those  of  the  last  two  or  three 
peripherals  are  somewhat  flattened;  and  they  notch  the  upper  face  of  the  bone. 

The  first  costal  has  a  maximum  width  of  98  mm.  The  second  is  66  mm.  wide;  the  third, 
60  mm.;  the  fourth,  46  mm.,  all  measured  at  the  costo-vertebral  sulcus.  At  the  sutural 
borders  these  bones  are  5  mm.  thick. 

The  surface  of  most  of  the  bones  is  more  or  less  roughened;  and  on  many  ot  them,  espe- 
cially the  costals,  there  are  present  scattered  pits,  each  about  3  mm.  in  diameter.  These  pits 
are  less  conspicuous  on  the  hinder  peripherals. 


Peripheral. 

Length. 

Height. 

Thickness. 

Width. 

Lower  face. 

Inner  face. 

I 

77 

43 

1        'i 

z 

40 

18 

3 

70 

32± 

29                3o± 

4 

73 

36 

29                40 

S 

75 

47 

34                43 

6 

SO± 

48       :       3o± 

7 

92 

65± 

57       !       ^* 

g 

90 

16 

9 

10 

" 

10 

87 

gg 

'0 

1 

144 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


The  area  of  the  scutes  of  the  carapace  is  distinctly  markt.  The  nuchal  scute  measures 
58  mm.  along  the  free  border;  90  mm.  along  the  posterior  border.  Fore  and  aft  it  is  only  20  mm. 
The  first  vertebral  had  a  width  of  about  200  mm.  Its  length  was  100  mm.  The  second  vertebral 
was  100  mm.  wide  and  150  mm.  long.  Behind  the  first  peripheral  the  costo-marginal  sulcus 
ran  along  the  unossified  space  between  the  costals  and  the  peripherals. 

The  plastron  evidently  had  the  form  presented  in  0.  gibbi.  The  piece  of  the  bone  consid- 
ered by  Cope  as  the  epiplastron  is  the  anterior  outer  end  of  the  hyoplastron.  At  the  axillary 
notch  the  hyoplastron  had  a  thickness  of  1 1  mm.  At  the  inguinal  notch  the  hypoplastron  was 
14  mm.  thick.  As  in  the  other  species,  there  was  an  interchange  of  digitations  between  the 
hypoplastron  and  the  xiphiplastron. 

Cope  figured  the  right  humerus.  This  bone  lacks  the  head,  both  trochanters,  and  a  little 
of  the  distal  end.  The  original  length  must  have  been  close  to  120  mm.  The  radial  and  the 
ulnar  crests  made  apparently  something  more  than  a  right  angle  with  each  other.  The  shaft 
is  bent  and  flattened.  The  dorso-ventral  diameter  is  13  mm.;  the  horizontal  diameter,  19  mm. 
The  width  of  the  distal  end  is  38  mm.  The  femur  is  practically  complete.  The  extreme 
length  is  132  mm.  The  bone  resembles  closely  that  of  Chelydra.  The  planes  of  the  tibial  and 
the  fibular  crests  make  a  right  angle  with  each  other.  The  diameter  of  the  shaft  is  14  mm.; 
that  of  the  distal  end,  36  mm. 

In  the  American  Museum  of  Natural  History  are  portions  of  a  large  individual  which  is 
referred  to  this  species.  There  are  present  peripherals  7  to  1 1  inclusive  of  the  left  side,  periph- 
erals eight,  ten,  and  eleven  of  the  right  side,  and  a  considerable  part  of  the  hindermost 
suprapygal.  With  these  are  other  bones,  some  or  all  of  which  may  belong  to  another  individual, 

possibly  to  another  species.  These  con- 
sist of  2  complete  costals,  3  neurals,  the 
left  hyoplastron  lacking  the  inner  end, 
the  left  hypoplastron  lacking  a  small 
portion  of  the  outer  end,  and  a  femur. 
Besides  these,  there  are  parts  of  first, 
second,  and  third  suprapygals  that  can 
not  belong  to  the  same  individual  as 
did  the  peripherals.  All  these  bones 
are  included  under  the  number  1132. 
This  is  the  specimen  mentioned  by  Cope  (Ext.  Batr.,  Rept.,  etc.,  p.  142)  as  having  been 
found  at  Hornerstown,  Monmouth  County,  New  Jersey. 

The  peripherals  (plate  26,  fig.  3)  indicate  a  large  individual,  with  a  carapace  about  825  mm. 
long.  The  dimensions  of  the  peripherals  are  given  in  the  table  above,  the  measurements 
being  taken  as  in  the  case  of  the  type  specimen. 

The  pits  for  the  rib-ends  entering  the  hinder  three  peripherals  are  flattened,  as  in  the  No. 
2351,  and  similarly  they  notch  the  upper  face  of  the  bones.  None  of  the  peripherals  present 
was  suturally  articulated  with  the  costals,  but  the  eleventh  was  sutured  with  the  hindermost 
suprapygal.  The  latter  had  a  length  of  about  75  mm.  and  a  width  of  180  mm.  It  was  there- 
fore quite  different  from  that  of  0.  gibbi. 

A  fragment  that  must  have  belonged  to  another  individual  presents  the  first,  second,  and  a 
part  of  the  third  suprapygals,  and  a  part  of  the  eighth  costal.  The  first  suprapygal  is  about 
40  mm.  long  and  the  width  is  the  same.  The  second  suprapygal  has  a  length  of  45  mm.  and 
a  width,  along  the  nearly  straight  hinder  border,  of  about  130  mm.  Of  the  third  there  is  only 
a  small  piece.  The  first  suprapygal  is  crost  by  the  sulcus  between  the  fourth  and  the  fifth 
vertebral  scutes. 

One  of  the  costals  is  probably  the  third  of  the  right  side.  It  has  a  length,  over  the  curve,  of 
about  275  mm.,  not  including  the  projecting  rib-end.  The  breadth  near  the  proximal  end  is 
87  mm.;  near  the  distal  end,  about  95  mm.  The  thickness  at  the  sutural  edges  is  7  mm.  The 
distal  end  had  not  been  sutured  with  the  peripherals.  Articulated  with  this  costal  is  a  neural, 
probably  the  third.  Its  length  originally  was  about  90  mm.;  its  breadth  anteriorly  is  58  mm. 
The  posterior  end  is  narrowed  and  rounded.  The  costal  and  this  neural  supported  portions 
of  the  third  and  fourth  vertebral  scutes.  The  fourth,  at  the  hinder  border  of  the  costal,  had  a 
width  of  about  140  mm.;  the  third  was  apparently  slightly  narrower. 


• 

Width. 

PeripheraL 

Length. 

Height. 

Thickness. 

Lower  face. 

Inner  face. 

7 

■13 

78 

67 

44 

8 

114 

93 

90 

14 

9 

106 

103 

17 

10 

I  OS 

117 

16 

II 

95± 

no 

16 

THALASSEMYDID^.  l^C 

All  the  bones  of  the  carapace  here  described  are  plentifully  furnisht  with  pits.  These  vary 
in  size  from  I  to  lo  mm.  in  diameter.  That  some  of  them  are  not  the  result  of  disease  or 
parasites  can  hardly  be  affirmed,  but  they  must  have  been  produced  during  the  life  of  the 
individual. 

The  plastron  may  not  have  belonged  to  the  individual  that  furnisht  the  peripherals;  but 
the  size  befits  it.  In  form  it  agrees  with  that  of  O.  gibhi.  At  the  narrowest  portion  of  the 
bridge  the  hyoplastron  and  hypoplastron  are  each  67  mm.  wide.  As  nearly  as  can  be  deter- 
mined, the  width  of  the  plastron  from  side  to  side  was  about  480  mm.  There  was  evidently 
a  fontanel  inclosed  by  the  two  plastral  bones  mentioned  and  the  peripherals.  There  was 
another  at  the  crossing  of  the  median  and  the  hyohypoplastral  sutures.  There  was  probably 
still  another  at  the  midline  just  in  front  of  the  xiphiplastrals. 

The  thickness  of  the  bones  at  the  bridge  is  20  mm. 

The  femur  lacks  the  distal  end.  In  form  it  resembles  that  of  supposed  0.  sopitus,  as 
figured  by  Cope;  but  the  size  is  greater.    The  diameter  of  the  shaft  is  i8  mm. 

No.  2216  of  the  American  Museum  of  Natural  History  comes  from  some  unknown  locality 
of  the  Cretaceous  greensand  of  New  Jersey,  and  forms  a  part  of  the  Cope  collection.     It 


Figs.  169-171. — Osteopygis  horealis.     Portion  of  carapace  and  lower  jaw. 

169.  Front  of  carapace  of  specimen  regarded  by  Cope  as  0.  sopitus.    No.  2351  A.  M.  N.  H.    c.  p.  j,  first 

costal  plate;   nu. />,  nuchal  plate;   nu.  j,  nuchal  scute;   /ffr.  i,  first  left  peripheral.     XJ 

170.  Lower  jaw,  seen  from  above.     No.  2216  A.M.N.H.     X^ 

171.  Section  along  symphysis  of  same  jaw.     Xi 

is  referred  confidently  to  the  present  species,  altho  some  differences  may  be  observed. 
It  furnishes  peripherals  three,  four,  six  to  ten  of  the  left  side,  five  and  eight  of  the  right  side; 
the  eleventh  of  one  side  or  the  other;  the  outer  end  of  the  left  hypoplastron;  and  a  large  part 
of  the  lower  jaw.    The  latter  is  here  described  and  figured. 

Fig.  170  represents  the  jaw  as  seen  from  above.  Fig.  171  is  a  section  along  the  symphysis. 
The  length  of  the  symphysis  is  62  mm.  The  thickness  at  the  hinder  end  of  the  symphysis 
is  18  mm.  This  is  gradually  reduced  forward.  The  symphysis  extends  backward  about  9  mm. 
behind  the  line  joining  the  mental  foramina.  The  width  at  the  mental  foramina  is  92  mm.  The 
crushing  surface  is  broad  and  flat,  rising  at  the  sides  to  the  cutting-edges.  For  a  distance  of 
about  32  mm.  from  the  tip  the  cutting-edges  are  acute  and  are  directed  outward;  they  then 
become  obtuse,  as  is  shown  by  section.  There  certainly  was  no  upturned  beak  at  the  tip  of  the 
jaw.  Along  the  inside  of  the  rami  and  behind  the  symphysis  is  a  deep  groove.  The  lateral 
halves  of  the  jaw  are  solidly  co-ossified,  but  there  remain  distinct  traces  of  the  suture. 

Osteopygis  horealis  differs  from  0.  emarginatus,  O.  gibbi,  and  0.  robustus  in  not  having 

the  peripherals  between  the  second  and  the  eleventh  joined  by  suture  with  the  distal  ends  of 

the  costals.    From  0.  erosus  it  differs  in  having  bones  of  much  thinner  and  lighter  construction. 

The  anterior  peripherals  are,  relatively  to  their  length,  of  less  height.    In  0.  horealis  the  pits  for 

10 


146 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


the  ribs  notch  both  the  upper  and  the  lower  faces  of"  the  peripherals  behind  the  seventh;    in 
O.  erosus  they  notch  only  the  upper  borders. 

0.  platylomus  differs  in  having  the  anterior  peripherals  higher  in  proportion  to  their 
length  and  in  having  the  upper  border  of  the  first  and  second  thicker.  In  O.  platylomus  the 
rib-pits  of  the  sixth  and  seventh  peripherals  are  decidedly  flattened;  in  0.  borealts  they  are 
conical.    O.  chelydrinus  differs  in  having  the  free  border  of  the  hinder  peripherals  angulated. 

Osteopygis  platylomus  Cope. 

Figs.  172-180. 

Osteopygis  platylomus.  Cope,  Amer.  Naturalist,  iii,  1869,  p.  89;  Cook's  Geo!.  New  Jersey,  l868  (1869), 
p.  735;  Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1869,  pp.  135,  137,  and  p.  ii,  figs.  38,  39;  Vert.  Cret. 
Form.  West,  1875,  p.  258. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  441. 

The  type  of  Cope's  Osteopygis  platylomus  is  a  fragmentary  specimen  which  belongs  to  the 
Academy  of  Natural  Science  of  Philadelphia.  It  was  presented  to  that  institution  by  Samuel 
Ashhurst,  having  been  discovered  in  the  uppermost  greensand  bed  of  the  Cretaceous,  at  Pem- 
berton,  Burlington  County,  New  Jersey.    It  now  consists  of  the  anterior  half  of  one  neural, 


Figs.  172  and  173. — Osteopygis  platylomus.     Portions  of  type. 
172.  Part  of  a  neural.     X§.  173.  Pygal,  suprapygal,  and  tenth  and  eleventh  peripherals.     X^. 

most  of  the  suprapygal,  a  portion  of  the  nuchal,  wholes  or  parts  of  all  the  peripherals  of  the 
right  side,  except  the  fifth,  wholes  or  parts  of  the  first,  third,  sixth,  eighth,  ninth,  tenth  of 
the  left  side,  many  fragments  of  costals  and  portions  of  the  plastron.  It  appears  that  a  few 
parts  have  been  lost  since  Cope  described  the  specimen. 

Cope  estimated  the  length  of  the  carapace  at  2  feet  2  inches.  The  writer  regards  the  length 
as  having  been  close  to  30  inches  or  about  750  mm. 

The  fragment  of  neural  (fig.  172)  is  crost  by  a  sulcus  and  is  therefore  probably  either 
the  third  or  the  fifth.  It  is  deeply  notcht  in  front  for  the  preceding  neural,  and  this  notch  gives 
evidence  that  the  neural  was  not  the  first  one.    The  greatest  width  of  the  bone  is  56  mm. 

The  bone  described  by  Cope  as  the  "  posterior  vertebral  "  is  really  the  suprapygal.  Only  a 
portion  of  the  left  end  of  the  nuchal  remains.  It  is  articulated  to  a  portion  of  the  first  left 
peripheral.  The  free  edge  is  obtuse  and  at  the  suture  with  the  first  peripheral  the  thickness  is 
17  mm.  The  bone  extends  backward  from  the  free  border  a  little  more  than  60  mm.,  to 
articulate  with  the  first  costal.  Here  the  thickness  is  only  about  6  mm.  The  first  marginal 
scute  occupies  the  outer  end  of  the  nuchal  and  the  anterior  end  of  the  first  peripheral.  Along 
the  free  border  it  is  58  mm.  and  it  extends  backward  from  the  free  border  of  the  bone  ^7,  mm. 
Cope  states  that  the  nuchal  scute  was  confluent  with  the  first  vertebral;  but  the  writer  regards 


THALASSEMYDID^. 


H7 


Width. 

Peripheral. 

Length 
free  border. 

Height 

at  sulcus. 

Lower  face. 

Inner  face. 

, 

7' 

5^ 

9 

S3 

2 

75 

49 

'5 

47 

3 

7° 

17 

37± 

4 

73 

29 

37  ±      1 

5 

6 

86 

5' 

41 

37 

7 

88 

58 

50 

»9 

8 

90 

68 

65 

20 

9 

88 

5^ 

64 

lO 

II 

80 

95 

this  as  a  mistake.  After  passing  about  6  mm.  the  sulcus  between  the  nuchal  scute  and  the 
first  marginal,  the  sulcus  between  the  nuchal  and  the  vertebral  scutes  suddenly  becomes  very 
shallow,   but  the  writer  believes  that  it  continues  on  in  its  usual  position. 

A  considerable  part  of  the  suprapygal  (fig.  173)  is  missing.  Cope's  statement  that  it  is 
only  2  inches  and  4  lines  wide  is  an  error  or  meant  to  apply  to  some  other  bone.  The  bone  in 
question  is  at  least  1 10  mm.  wide.  It  occupies  an  area  that  in  0.  gibbi  is  occupied  by  two  bones, 

but  a  close  examination  shows  a  line  running 
from  the  upper  angle  of  one  eleventh  peripheral 
to  that  of  the  opposite  side,  along  which  2  bones 
have  co-ossified.  The  angulation  of  the  upper 
border  of  the  eleventh  peripheral  shows  that 
there  were  two  suprapygals.  It  is  probable  that 
the  sutural  edge  oftheeleventh  peripheral  joined 
the  anterior  suprapygal  instead  of  the  eighth 
costal  plate.  The  dimensions  of  the  peripherals 
are  shown  in  the  table. 

The  sixth  peripheral  (figs.  174,175)  presents 
three  faces,  an  upper  concave,  a  lower  convex, 
and  an  inner  irregular.  The  upper  and  lower 
faces  meet  at  the  acute  free  border.  In  the 
inner  face  is  a  large,  somewhat  flattened  pit  for  the  end  of  a  rib.  Its  mouth  occupies  one- 
half  the  length  of  the  face.  Along  the  lower  border  of  the  face  are  two  or  three  shallow  pits 
for  digitations  of  the  hypoplastron. 

As  we  proceed  forward  from  the  sixth  peripheral  the  free  border  becomes  less  acute, 
until,  on  the  third,  it  is  obtuse  and  the  upper,  now  convex,  face  rounds  into  the  lower.  On  the 
second  and   first  peripherals  (figs.  176,  177)  the  lower  face  becomes  the  obtuse  free  border 

of  the  bones.  The  inner  faces  of 
the  fourth  and  the  third  contain  pits 
for  the  corresponding  rib-ends.  The 
inner  face  of  the  second  has  a  large 
excavation  which  received  the  anterior 
outer  process  of  thehyoplastron.  Fig. 
176  represents  the  first,  second,  and 
third  peripherals  of  the  right  side. 
The  upper  border  of  the  first  and 
the  anterior  half  of  that  of  the  second 
peripheral  had  a  sutural  articulation 
with  the  first  costal  (fig.  176).  The 
thickness  of  these  borders  is  6  mm. 
The  hinder  half  of  the  upper  border 
of  the  second  and  the  upper  borders  of  all  the  other  peripherals  to  the  eleventh  are  smooth. 
The  upper  border  of  the  eleventh  appears  to  have  articulated  with  the  suprapygals,  as 
already  stated. 

Passing  backward  from  the  sixth  peripheral,  the  upper  and  lower  borders  of  all  the 
peripherals  broaden  and  become  flatter.  The  inner  face  narrows,  and  finally  on  the  eighth 
(figs.  178,  179)  and  succeeding  peripherals,  curves  into  the  lower  face.  Each  of  these  periph- 
erals, except  the  eleventh,  has  a  pit  for  a  rib-end.  The  hindermost  peripherals  are  thin,  the 
ninth  being  14  mm.  thick,  the  eleventh  about  10  mm.  The  flattening  of  the  rib-pits  begins  with 
the  sixth  peripheral.  The  pygal  is  represented  by  fig.  173.  Fig.  180  shows  one  lateral  border. 
There  are  present  many  fragments  of  costal  bones,  but  no  complete  costal.  The  remains 
seem  to  show  that  the  carapace  was  rather  flat.  The  thickness  of  the  costals  near  the  neurals 
was  about  6  mm.;  near  the  distal  ends,  about  5  mm.  The  rib-heads  were  strongly  developt. 
Distally,  each  rib  projected  beyond  the  costal  and  entered  the  pit  in  a  corresponding  periph- 
eral. The  edges  of  the  costal  plates  approacht  closely  the  upper  borders  of  the  peripherals. 
On  the  proximal  ends  of  two  costals  the  costo-vertebral  sulci  run  along  about  35  mm.  from 
the  neural  border.    Another  fragment  shows  that  the  vertebral  scute  was  strongly  angulated 


Fig.  174. — Osteopygis  platylomus.     Sixth  left  peripheral 
of  type.     Xj. 

a,  from  above;  6,  hinder  end;  c,  anterior  end. 


148 


KOSSII,    TURTLES    OF    NORTH    AMERICA. 


laterally.  The  distal  end  of"  a  costal  bone  is  70  mm.  wide.  The  surface  of  the  bones  is  usually 
moderately  smooth,  but  markt  by  irregular,  rather  straight,  vascular  grooves.  The  sulci  are 
usually  quite  distinct. 

The  nuchal  scute  is  present,  as  stated.  Its  lateral  extent  is  conjectural;  the  fore-and-att 
width  is  about  30  mm.  The  widths  of  the  vertebral  scutes  can  not  be  exactly  determined; 
but  thev  all  appear  to  correspond  closely  to  those  of  O.  gtbbi  Wieland.     The  first  evidently 


.76 


177- 


.78. 


179. 


Figs.  175-180. 


-Osteopygis  platylomus. 
Type.      Xj. 


Peripherals  and  sections. 


175.  Sixth,  seventh,  and  eighth  right  peripherals. 

176.  First,  second,  third,  and  fourth  right  peripherals. 

177.  Sections  of  first  and  second  left  peripherals,    a,  distal  end  of  second;   h, 
proiimal  end  of  second;   c,  near  proximal  end  of  first. 

178.  Hinder  end  of  eighth  peripheral. 

179.  Front  end  of  eighth  peripheral. 

180.  Section  along  right  articular  border  of  the  pygal. 

extended  laterally  to  about  the  middle  of  the  first  peripheral.  The 
eleventh  reacht  laterally  the  hinder  border  of  the  pit  for  the  last  rib. 
The  costo-marginal  sulci  run  along  on  the  upper  borders  of  the  first  and  second  peripherals, 
then  disappear,  to  reappear  on  the  upper  borders  of  the  eighth  to  the  eleventh.  From  the 
third  to  the  eighth  peripherals  the  sulci  occupied  doubtless  the  space  between  the  costals  and 
the  peripherals. 

At  present  there  remain  of  the  plastron  only  a  part  of  the  left  hyoplastron,  most  of  the  left 
hypoplastron,  and  most  of  the  right  xiphiplastron.  The  plastron  seems  not  to  have  differed 
in  any  important  way  from  that  of  0.  borealis.  Evidently  there  was  a  fontanel  between  the 
hyoplastra  in  front  and  the  hypoplastra  behind.  At  the  narrowest  part  of  the  bridge  the  hypo- 
plastron is  58  mm.  wide.  The  thickness  at  the  inguinal  notch  is  16  mm.  No  sulci  are  to  be 
seen  on  these  bones,  except  a  faint  one  near  the  base  of  the  xiphiplastron.  To  the  present 
writer  it  seems  evident  that  the  bones  on  the  right  of  Cope's  figure  of  the  plastron  of  this  species 


THAI.ASSKMYDID^. 


149 


have  been  taken  from  the  plastron  of  one  of  the  specimens  described  by  him  as  0.  emarginatus. 
Remarks  on  this  specimen  are  made  under  the  last-named  species.  In  Cope's  figure  of  the 
plastron  the  hyoplastron  on  the  left  side  of  the  drawing  is  placed  too  horizontally.  The  anterior 
outer  angle  ought  to  be  directed  strongly  forward.  This  species  resembles  O.  borealis.  For 
differences  see  under  the  latter  species. 

Osteopygis  sopitus  Leidy. 

FiG;s.  181-184. 

Chelone  sopita,  Leidy,  Smithson.  Contrib.  Knowl.,  xiv,  1865,  pp.  104,  119. — Maack,  PalKontographica, 

XVIII,  1869,  pp.  238,  283.  , 

Osteopygis  sopitus,  Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  441  (in  part). 

The  type  specimen  of  the  present  species  has  not  hitherto  been  figured.  It  belongs  to  the 
New  Jersey  State  collection  and  is  at  Rutgers  College,  New  Brunswick,  New  Jersey,  where 
the  writer  has  examined  it.  This  type  consisted  of  4  peripherals,  but  Leidy  was  uncertain 
whether  or  not  they  belonged  to  one  individual.  These  bones  had  been  obtained  in  the 
Cretaceous  greensand  at  Tinton  Falls,  Monmouth  County,  New  Jersey,  probably  in  the  upper 
bed.  Other  specimens,  which  were  mentioned  by  Leidy  in  his  description  of  this  species  and 
figured,  were  afterwards  referred  by  Cope  to  Lvtoloma  angusfn,  and  probably  correctly  so. 


Figs.  181-184. — Osteopvgis  sopitus.     Peripheral  of  type. 

181.  Seventh.^  peripheral,  with  section. 

182.  Hinder  peripheral,  with  section  (i8i<j).    The  interrupted  lii 
section  indicates  the  depth  of  the  pit. 

185.  Hinder  peripheral. 
184.  .Section  of  a  periplierai. 

Other  specimens  were  referred  b\'  Cope  to  Leidy's  species.  One  ot  these  had  been 
secured  at  Harrisonville,  Salem  County,  New  Jersey,  in  a  sort  of  limestone.  This  specimen  is 
now  in  the  American  Museum  of  Natural  History  and  has  the  number  2361.  Almost  certainly 
it  is  not  a  species  of  Osteopygis,  and  it  has  in  the  present  work  been  referred  provisionally 
to  Rhetechelys  platyops  (Cope). 

The  four  peripherals  of  the  type  belonged  behind  the  bridges.  Figures  taken  from  three 
of  these  are  here  presented.  Fig.  181  represents  in  outline  one  which  is  regarded  as  being  the 
right  seventh.  It  is  115  mm.  long,  59  mm.  wide  near  the  anterior  end,  20  mm.  thick  at  this  end, 
and  12  mm.  at  the  posterior  end.  There  are  3  faces — an  upper,  a  lower,  and  an  inner,  or 
visceral.  The  pit  for  the  rib  is  nearer  what  is  regarded  as  the  hinder  end  and  is  somewhat 
flattened  in  section.  Above  the  figure  is  a  section  taken  at  the  anterior  end  of  the  bone.  Another 
peripheral  (fig.  182)  is  about  87  mm.  long,  82  mm.  wide,  18  mm.  thick  at  one  end,  14  mm.  at 
the  other.  In  the  visceral  face  is  a  pit  for  the  end  of  a  rib.  Each  diameter  of  the  pit  at  its 
opening  is  9  mm.  The  upper  face  is  quite  concave  from  the  acute  free  border  to  the  costal 
border.  Near  the  figure  is  a  section  (182(7)  taken  at  the  thicker  end  of  this  peripheral,  which 
represents  the  diameter  and  depth  of  the  rib-pit.  Another  peripheral,  probably  a  ninth  or 
tenth,  has  the  costal  border  broken  away.  The  rib-pit  is  flattened.  Figure  183  is  a  section  of 
this  bone.  Its  greatest  thickness  is  24  mm.  Fig.  184  is  a  section  taken  along  the  transverse 
sulcus  of  a  fragment  representing  about  one-half  of  a  peripheral.    The  upper  and  lower  faces 


150  FOSSIL    TURTLES    OK    NORTH    AMERICA. 

measure  48  mm.  each,  while  the  concave  visceral  face  is  22  mm.  wide.    The  mouth  of  the  pit 
is  circular. 

Cope  referred  to  this  species  a  specimen  which  now  has  the  number  2351  of  the  American 
Museum  and  which  is  regarded  here  as  belonging  to  the  species  since  described  by  Wieland 
as  Propleura  horealis,  here  as  Osteopygis  borealts.  If  all  of  the  peripherals  described  by  Leidy 
belong  to  the  same  species  this  can  not  be  the  same  as  Cope's  species;  for  the  peripheral  here 
represented  by  fig.  181  is  too  long  and  narrow.  Furthermore,  the  peripheral  with  the  missing 
costal  border  is  too  thick.  In  the  doubt,  therefore,  it  seems  best  to  regard  Leidy's  materials 
and  Cope's  as  belonging  to  distinct  species,  making  the  elongated  peripheral  of  Leidy's  spec- 
imens the  type  of  his  species  and  leaving  it  to  future  discoveries  to  determine  whether  or 
not  any  of  Leidy's  materials  are  co-specific  with  Cope's  specimen. 

Genus  CATAPLEURA  Cope. 

A  genus  not  well  known.  Nuchal  bone  little  broader  than  the  anterior  peripherals. 
Nuchal  and  first  and  second  peripherals  suturally  joined  to  the  first  costal  bone.  The  other 
peripherals  to  the  eleventh  probably  not  suturally  connected  with  the  disk  of  the  carapace.  No 
pit  in  the  second  peripheral  for  the  hyoplastron.  A  pit  in  the  eleventh  peripheral  for  the  rib  of 
eight  costal.  Plastron  probably  resembling  that  of  Osteopygis,  but  not  extending  so  far  along 
the  peripherals. 

Type :    Catapleura  repanda  Cope. 

This  genus  differs  from  Lytoloma  in  having  the  two  anterior  peripherals  solidly  joined  to 
the  first  costal.  It  differs  from  Osteopygis  in  the  much  narrower  nuchal  bone  and  in  having 
no  pit  in  the  second  peripheral  for  the  process  of  the  hyoplastron.  From  both  Lytoloma  and 
Osteopygis  it  differs  in  the  much  thicker  posterior  peripherals. 

The  genus  was  establisht  by  Cope  in  1870  (Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  p. 
143).  On  page  235  of  the  work  cited  Cope  exprest  himself  in  doubt  whether  there  were 
nine  or  ten  costal  plates  present.  In  1884  (Vert.  Tert.  Form.  West.,  p.  112)  doubt  is  exprest 
whether  there  were  9  costals.  There  can  now  be  no  doubt  that  this  genus,  like  Osteopygis 
and  the  great  majority  of  turtles,  had  only  8  pairs  of  costals. 

Catapleura  repanda  Cope. 

Figs.  185-188. 

Osteopygis  repandus,  CoPE,  Proc.  Acad.  Nat.  Sci.  Phila.  1868,  p.  147  (notn.  nud.). — Hay,  Bibliog.  and 

Cat.  Foss.,  Vert.  N.  A.,  1902,  p.  441. 
Propleura  repanda.  Cope,  Cook's  Gaol.  New  Jersey,  1868  (1869),  p.  7^5  (nom.  nud.). 
Catapleura  repanda.  Cope,  Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1869,  p.  143,  plate  vii,  fig.  2;  Vert.  Cret. 

Form.  West,  1875,  p.  259. 

The  present  species  is  based  on  very  meager  materials  and  none  additional  has  been 
discovered  since  the  first  description  of  the  species.  The  type  is  now  in  the  American  Museum 
of  Natural  History  and  consists  of  a  part  of  the  nuchal,  the  succeeding  three  peripherals  and  a 
part  of  the  fourth  of  the  right  side,  the  first  of  the  left  side,  and  four  other  peripherals,  one 
nearly  complete  costal  and  parts  of  others,  and  a  portion  of  a  femur.  The  catalog  number  is 
2353.  These  bones  were  obtained  from  the  upper  bed  of  Cretaceous  greensand  at  Barnesboro, 
Gloucester  County,  New  Jersey. 

The  nuchal  bone  (fig.  185)  is  remarkable  for  its  narrowness  fore  and  aft,  being  only  47  mm. 
The  widths  of  the  first  and  second  peripherals  are  respectively  43  mm.  and  44  mm.  The 
free  border  of  the  nuchal  is  somewhat  obtuse  and  the  thickness  soon  becomes  10  mm.,  at 
the  end  of  the  bone.  The  posterior  border  articulated  suturally  with  the  first  costal.  The 
posterior  sutural  edge  is  oblique  to  the  surfaces  of  the  bone  and  the  nuchal  slightly  overlapt  the 
first  costal.  The  thickness  of  this  border  is  8.5  mm.  The  posterior  border  of  the  nuchal  was 
much  wider  from  side  to  side  than  the  anterior  border.  On  the  end  of  the  nuchal,  nearer  the 
anterior  border,  there  is  a  notch  which  receives  a  process  of  the  first  peripheral  (fig.  185). 
The  latter  measures  50  mm.  along  the  anterior  border,  17  mm.  along  the  posterior.  Its  free 
border  is  more  obtuse  than  that  of  the  nuchal.  The  second  peripheral  (fig.  185)  extends  53 
mm.  along  the  free  border.    It  is  13  mm.  thick  near  the  free  border,  7  mm.  thick  at  the  hinder 


THALASSEMYDID^. 


151 


border.  The  hinder  border  both  of  this  bone  and'of  the  first  peripheral  is  oblique  and  overlapt 
the  first  costal,  as  did  the  nuchal.  The  hinder  half  of  the  upper  border  of  the  second  peripheral 
is  broken  away  and  we  can  not  tell  how  much  of  it  was  sutured  to  the  costal.  There  is  no  pit 
in  the  second  for  the  anterior  outer  angle  of  the  hyoplastron,  and  it  is  not  probable  that  the 
latter  bone  extended  so  far  forward. 

The  third  peripheral  is  60  mm.  long  on  the  thickened  and  obtuse  free  border.  On  the  inner 
face  is  a  deep  pit,  directed  backward,  for  the  rib-end  of  the  first  costal.  Below  this,  in  the  pro- 
jecting edge  is  a  notch,  possibly  for  a  digitation  of  the  hyoplastron.  Of  the  fourth  peripheral 
there  is  present  only  a  portion.  Its  lower  face  is  26  mm.  wide,  and  this  makes  an  angle  of  ninety 
degrees  with  the  upper  face,  the  angle  where  they  meet  being  rounded  ofl^.  The  upper  borders 
of  the  third  and  the  fourth  peripherals  are  broken  away.  Cope  figured  what  he  regarded  as  the 
sixth  peripheral,  and  there  is  a  fragment  of  a  peripheral,  which  he  has  markt  as  the  sixth; 
but  it  is  impossible  now  to  to  say  that  the  bone  present  is  the  one  figured.  The  bone  has  one 
face,  apparently  the  upper,  44  mm.  wide.    Another  face,  somewhat  concave,  is  separated  from 


¥iGS.  l^^-lS^.—Catapleurarepandii.  Portions  of  shell  of  type.   Xj. 

185.  Nuchal,  and  first  and  second  peripherals,     nu.p,  nuchal  bone;    per.  l,  per. 
2,  first  and  second  peripherals. 

186.  Portions  of  the  eighth  and  ninth  peripherals.     Free  border  toward  the  right. 

187.  Section  across  ninth  peripheral.  188.  Third  or  fifth  costal. 

this  by  a  subacute  free  border.  Cope  has  figured  what  he  regarded  as  the  eighth  and  part  of  the 
ninth  peripherals.  In  reality,  there  is  only  a  small  portion  of  the  eighth  and  about  two-thirds 
of  the  ninth  (fig.  i86).  Evidently  these  belong  to  the  right  side,  since  the  intermarginal  sulcus 
crosses  in  front  of  the  rib-pit.  The  latter  is  in  the  hinder  half  of  each  bone.  The  upper  border 
of'the  upper  face  of  both  these  bones  is  missing,  but  that  part  of  the  face  of  the  ninth  which 
remains  is  47  mm.  wide  and  is  slightly  concave.  The  lower  face,  also  slightly  concave,  is  46 
mm.  wide.  The  inner  face  has  been  about  25  mm.  wide.  Fig.  187  is  a  section  of  the  ninth 
along  the  intermarginal  sulcus.  The  outer  free  border  of  the  bone  is  acute  and  has  projected 
slightly  at  the  end  of  the  intermarginal  sulcus,  making  the  free  border  somewhat  repand. 

On  the  free  border  and  between  the  two  bones  here  described  is  a  long  notch  which,  during 
the  life  of  the  animal,  inclosed  a  distinct  ossicle.  This  reminds  us  of  similarly  disposed  ossicles 
described  by  Wieland  as  occurring  in  his  Lytolonia  angusta  (L.  unelandi),  and  which  he  was 
inclined  to  regard  as  a  part  of  a  disappearing  primitive  osteo-dermal  armor  of  turtles.  From  the 
manner  of  growth  of  the  horny  scutes  one  would  rather  expect  to  find  such  bones,  if  a  part  ot 
the  ancient  armor,  at  the  ends  of  the  intermarginal  sulci. 


152  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

There  is  present  a  part  of  a  peripheral  which  Cope  has  labeled  as  the  tenth.  The  upper 
borders  of  both  the  upper  and  lower  faces  are  missing,  but  these  faces  are  yet  58  mm.  wide.  At 
its  upper,  or  proximal,  border,  the  bone  is  18  mm.  thick.  The  hinder  half  of  the  bone  is  lost 
but  enough  apparently  remains  to  show  a  part  of  the  rib-pit,  had  it  been  present  in  the  bone. 
Since  in  C.  ponderosa  the  eighth  costal  sent  its  rib-end  into  the  eleventh  peripheral,  it  is  prob- 
able that  there  was  no  pit  in  the  tenth.  If  the  bones  regarded  by  Cope  as  the  eighth,  ninth 
and  tenth  are  really  such  they  differ  greatly  from  the  corresponding  bones  of  Osteopygis, 
being,  relatively  to  their  length  and  height,  much  thicker. 

The  costals  are  extremely  interesting,  but  they  are  not  well  understood.  There  is  one  which 
is  nearly  complete,  quite  certainly  either  the  third  or  the  fifth.  It  has  a  width  of  about  50  mm. 
(fig.  188).  The  curvature  shows  that  the  carapace  was  considerably  archt  from  side  to  side. 
Cope  regarded  this  costal  as  that  of  the  right  side,  but  there  are  reasons  for  believing  that  it 
belongs  to  the  left.  One  sutural  border  is  thicker  and  has  the  suture  oblique  to  the  surface  of 
the  bone  in  such  a  way  that  it  must  have  been  overlapt  by  the  contiguous  bone.  We  have 
seen  that  the  hinder  border  of  the  nuchal  and  the  first  two  peripherals  overlapt  the  first  costal. 
It  seems  improbable  that  from  having  the  anterior  border  overlapt  in  the  first  costal  a  change 
would  be  made,  about  the  middle  of  the  shell,  to  having  the  posterior  border  overlapt.  The 
present  costal  can  not,  however,  be  the  first,  for  the  proximal  end  of  its  fellow  bone  is  present 
and  does  not  accurately  fit  to  the  nuchal  and  first  peripheral.  It  can  not  be  the  second,  for  it  is 
not  traverst  by  a  sulcus  separating  two  costal  scutes.  It  seems  probable  that  it  is  the  left 
third.  The  posterior  sutural  edge  is  at  right  angles  with  the  surface  and  hence  it  did  not  overlap 
the  succeeding  bone.  The  thickness,  too,  is  reduced  to  5  mm.  The  upper  surface  of  the  costals 
is  smooth.  On  the  one  described  there  are  parts  of  2  vertebral  scutes,  probably  the  second  and 
the  third.  On  the  supposed  posterior  border  of  the  bone  the  costo-vertebral  sulcus  is  25  mm. 
from  the  neural  border.    The  surfaces  of  the  peripherals  are  markt  by  zigzag  vascular  grooves. 

On  the  under  side  of  the  costal  is  seen  a  large  rib-head  and  stout  ridge  proceeding  from  it  to 
the  distal  end.  At  the  proximal  end  this  ridge  lies  a  little  nearer  to  the  supposed  anterior  border 
and  on  its  way  to  the  distal  end  it  gets  closer  to  this  border,  being  only  3  mm.  away  from  it 
finally.  In  his  description  Cope  states  this  ridge  lies  near  the  posterior  border.  In  front,  that 
is  on  the  side  next  the  beveled  border  of  the  costal,  there  is  a  rough  groove,  as  if  a  rudimentary 
first  rib  had  been  applied  against  the  ridge.  The  meaning  of  the  groove  is  unknown.  It  is 
found  in  three  of  the  costals  represented. 

Not  enough  of  the  femur  is  present  to  furnish  definite  information  regarding  its  structure. 
The  head  is  missing.  The  shaft  has  a  diameter  of  11  mm. 

What  is  determinable  regarding  the  vertebral  scutes  has  been  stated  above.  On  the 
nuchal  and  the  anterior  peripherals  the  marginal  scutes  rise  only  a  moderate  distance  above  the 
free  border  of  the  shell.  On  the  median  and  hinder  peripherals  the  costo-marginal  sulci  appear 
to  have  followed  the  unossified  space  between  the  costal  and  peripheral  bones.  The  nuchal 
bone  does  not  reach  the  midline,  and  hence  we  can  not  determine  exactly  what  was  its  width 
nor  that  of  the  nuchal  and  first  vertebral  scutes.  The  boundary  between  the  nuchal  scute  and 
the  first  marginal  is  believed  to  be  where  shown  in  fig.  185.  The  first  vertebral  scute  lacks  a 
considerable  space  of  reaching  the  outer  ends  of  the  nuchal  bone,  and  was,  hence,  evidently 
narrow.  The  first  marginal  rises  about  28  mm.  above  the  border  of  the  carapace;  the  second 
about  18  mm. 

Catapleura  ponderosa  Cope. 

Figs.  189,  190. 

Catapleura  ponderosa,  CoPE,  Proc.  Amer.  Philos.  See,  XII,  1 87 1 ,  p.  46 ;  Vert.  Cret.  Form.  West,  1 875, p.  259. 
Osteopygis  ponderosa,  Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  441. 

The  present  species  is  based  on  materials  even  less  satisfactory  than  is  C.  repanda.  They 
consist  of  portions  of  the  eleventh  peripheral  and  the  pygal,  portions  of  about  6  costals,  a 
part  of  a  supposed  hypoplastron,  a  scapular  arch,  a  considerable  part  of  a  humerus,  a  part  of 
a  femur  and  a  part  of  a  lower  jaw. 

The  type  is  now  in  the  American  Museum  of  Natural  History  and  has  the  number  1475. 
These  bones  were  obtained  by  Cope  from  the  uppermost  bed  of  Cretaceous  greensand,  at 
Hornerstown,  New  Jersey. 


THALASSEMYDID.i;. 


153 


The  pygal  bone  (figs.  189,  190)  had  a  width  of  about  80  mm.  along  the  free  border.  Some 
of  the  upper  border  has  crumbled  away,  but  the  height  of  the  bone  was  close  to  65  mm.  Its 
thickness  a  short  distance  below  the  upper  border  is  19  mm.  The  upper  surface  is  concave  fore 
and  aft;  convex  from  side  to  side.  On  the  lower  side  the  directions  of  these  forms  of  surface 
are  reverst.  The  free  border  is  acute.  The  upper  border  was  probably  suturally  articulated 
with  the  suprapygal.  On  neither  the  upper  nor  the  lower  side  of  this  bone  is  there  any  trace 
of  a  sulcus. 

Of  the  eleventh  peripheral  Cope  had  no  more  than  is  now  present,  the  hinder  half,  articu- 
lated with  the  pygal.  It  is  concave  from  the  free  edge  to  the  upper  border  on  the  upper  surface, 
rather  strongly  convex  on  the  lower  surface.  In  the  upper  border  there  remains  a  portion  of 
the  deep  pit  forthe  rib-head  of  the  eighth  costal.  The  greatest  thickness  of  the  bone  is  19mm. 
While  a  considerable  part  of  the  free  border  is  broken  away,  that  remaining  seems  to  indicate 
that  this  border  was  emarginate,  as  was  stated  by  Cope.    No  sulcus  appears  on  this  bone. 

Two  of  the  costals  represented  are  evidently  those  of  the  same  pair.  Cope  thought  they 
were  those  of  the  second  pair.  The  proximal  end  was  82  mm.  wide.  One  of  the  sutural 
borders  is  1 1  mm.  thick,  and  the  suture  is  oblique  to  the  surfaces  of  the  bone.  It  was  evidently 
overlapt  by  the  bone  to  which  it  was  articulated.  The  opposite  border  is  only  5  mm.  thick. 
Under  C.  repanda  reasons  have  been  given  for  regarding  the  border  bearing  the  oblique  suture 
as  the  anterior  one;  and  the  costals  of  the  two  species  are  so  similar  that  the  same  rule  applies 
here.    As  in  C.  repanda,  the  rib-head  is  strongly  developt,  as  well  as  the  rib  in  its  course  along 


Figs.  189  and  icp.—Catapleura  ponderosa.     Portions  of  type.      X§. 
189.  Pygal  and  eleventh  peripheral.  190.  Section  along  midline  of  pygal. 

the  under  side  of  the  costal.  As  in  C.  repanda,  this  rib  gets  nearer  and  nearer  the  thickened 
side  of  the  costal  on  its  way  toward  the  distal  end.  There  is  also  a  rough  groove  near  the  prox- 
imal end  of  the  front  of  the  ridge;  but  it  is  not  so  conspicuous  as  in  the  other  species.  More- 
over, it  is  seen  only  on  the  two  costals  supposed  to  belong  to  the  second  pair. 

On  none  of  the  costals  or  peripherals  are  there  observed  any  remains  of  sulci,  to  mark  the 
limits  of  the  horny  scutes.    The  costals  are  markt  by  very  distinct  branching  vascular  grooves. 

There  is  present  a  fragment  of  a  plastral  bone,  which  was  interpreted  by  Cope  as  the 
hinder  part  of  the  left  hypoplastron.  The  writer  finds  it  impossible  to  identify  the  bone  satis- 
factorily.   One  border  is  obtuse  and  14  mm.  thick.    The  opposite  border  is  thin  and  irregular 

Only  the  proximal  half  of  the  right  humerus  is  present.  The  long  axis  of  the  head 
measures  35  mm.,  the  shorter  2+  mm.  The  radial  process  is  missing,  but  it  continued  to  the 
head  of  the  bone.  The  ulnar  process  lacks  much  of  rising  to  the  level  of  the  head,  and  the  ridge 
descending  from  it  runs  well  down  on  the  shaft.  The  planes  of  the  radial  and  ulnar  processes 
make  with  each  other  an  angle  of  more  than  90°.  The  shaft  of  the  bone  is  comprest  having 
a  diameter  of  15  mm.  in  the  perpendicular  plane ;  of  1 1  mm.  in  the  horizontal.  It  is  therefore 
comprest  in  a  manner  directly  opposite  to  that  of  the  C/!(?/on/ic/a-.  ... 

The  femur  is  that  of  the  right  side  and  lacks  the  distal  end.  The  portion  remaming  is  93 
mm.  long;  and  the  whole  bone  must  have  been  about  120  mm.  long.  As  in  the  nriore  primitive 
turtles,  the  head  and  the  processes  resemble  those  of  the  humerus.  The  head  has  diameters 
respectively  of  23  mm.  and  30  mm. 


154 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


The  fibular  process  rises  only  to  the  lower  level  of  the  head.  The  tibial  process  is  broken 
off.  The  planes  of  the  two  made  with  each  other  an  angle  of  more  than  90°,  and  there  is  a 
broad  fossa  between  them,  open  below.  The  ridge  from  the  tibial  process  runs  far  down  on 
the  shaft.    The  least  diameter  of  the  latter  is  12  mm. 

The  present  species  appears  to  differ  from  C.  repanda  in  having  no  traces  of  sulci  between 
the  epidermal  scutes,  in  having  the  ridge  formed  from  the  rib  on  the  under  side  of  the  costal 
more  strongly  developt  and  more  angular,  and  apparently  in  having  the  hinder  peripherals 
more  recurved  toward  their  free  margins.  To  judge  from  the  types,  C.  ponderosn  was  con- 
siderably the  larger  species. 

In  his  description  of  this  species  Cope  mentions  a  portion  of  the  mandible  which  had 
accompanied  the  other  bones.  This  bone  is  now  at  hand.  It  consists  of  the  right  dentary.  The 
tip  of  the  dentary  and  the  hinder  portion  of  the  cutting-border  are  missing.  The  break 
between  two  dentaries  appears  to  have  followed  the  midline.  The  length  of  the  symphysis 
was  close  to  36  mm.  and  its  hinder  end  extended  back  to  a  line  joining  the  mental  foramina. 
The  latter  are  small.  From  the  symphysis  the  upper  surface  of  the  dentary  descends  slightly 
outward,  then  rises  considerably  to  the  cutting-border.  The  lower  side  of  the  dentary  is 
flat  for  a  considerable  distance  on  each  side  of  the  midline,  then  rises  in  a  strong  curve  to 
the  cutting-edge.  The  thickness  at  the  hinder  end  of  the  symphysis  is  1 1  mm.  The  jaw  is 
strongly  grooved  behind.  This  dentary  resembles  that  described  under  O.  chelydrinus;  but, 
having  the  same  width,  the  latter  is  thicker  and  heavier. 

Genus  LYTOLOMA  Cope. 

Lower  jaw  with   broad,  flat  crushing-surface  and  long  symphysis;   the  tip  not  beaked. 

Carapace  resembling  that  of  Caretta  caretta  but  less  pointed  behind.  None  of  the  anterior 
peripherals  suturally  articulated  with  the  costal  plates,  rib-pits  of  most  of  the  peripherals  in 
the  hinder  half  of  these  bones.  The  eleventh  peripheral  with  pit  for  rib  of  eighth  costal. 
Plastron  not  well  known,  but  believed  to  have  a  narrower  connection  with  the  carapace  than 
in  Osteopygis.  Limbs  not  well  known,  the  humerus  and  femur  supposed  to  have  about  equal 
development,  with  tendencies  toward  the  structure  of  the  same  parts  in  Cheloniidae. 

The  type  of  this  genus  is  Lytoloma  angusta  Cope.  This  is  represented  by  some  peripherals 
and  a  lower  jaw,  all  supposed  to  belong  to  the  same  individual.  Dr.  Wieland  has  described  and 
figured  a  considerable  portion  of  a  carapace  which  he  referred  provisionally  to  L.  angusta,  but 
which  is  here  placed  with  doubts  under  L.  wieland t. 

A  considerable  number  of  species  from  the  Eocene  of  England  and  Belgium  have  been 
arranged  under  this  genus,  after  having  been  assigned  variously  to  Chelone,  Euclastes,  Puppi- 
gerus,  Glossochelys,  Pachyrhynchus,  Thalassochelys,  and  Erquelinnesia.  For  the  discussion  of 
the  subject  the  reader  is  referred  to  the  original  papers.  These  are  cited  by  Mr.  Richard 
Lydekker  in  his  Catalogue  of  Fossil  Reptilia,  part  iii,  page  51. 

It  is  evident,  however,  that  few,  if  any,  of  these  species  really  belong  to  Lytoloma.  Owen 's 
Chelone  crassicostata,  the  palatal  view  of  which  is  figured  by  Lydekker  (Proc.  Zool.  Soc.  Lond., 
1889,  pi.  vi),  under  the  name  of  Lytoloma  crassicostatum,  has  the  choanae  pushed  backward  to 
the  hinder  third  of  the  skull,  and  the  palatine  bones  meet  for  a  considerable  distance  behind 
the  vomer.  In  the  article  accompanying  the  figure  just  cited  Mr.  Lydekker  informs  us  that 
Dollo's  species  originally  described  under  the  name  of  Pachyrhynchus  gosselett  is  identical 
with  Owen's  Chelone  crassicostata.  For  the  genus  represented  by  this  species  it  appears  that 
Dollo's  name  Erquelinnesia  will  have  to  be  employed. 

The  skull  of  Owen's  Chelone  planimentum  resembles  in  general  that  of  his  C.  crassicostata, 
but  its  palate  appears  not  to  have  been  described.  Nevertheless,  the  carapace  presents  several 
peculiarities.  The  neurals  have  the  antero-lateral  and  the  postero-lateral  sides  equal,  the  ribs 
present  themselves  on  the  under  side  of  the  costals  as  prominent,  narrow,  and  angular  ridges, 
and  the  peripherals  are  much  more  reduced  than  in  C.  crassicostata.  It  seems  probable  that 
we  have  here  a  distinct  genus,  and  for  this  Seeley's  name  Glossochelys  will  be  available. 

Dr.  W.  B.  Clark  has  publisht  (Johns  Hopkins  Univ.  Circ.  xv,  1895,  No.  4;  Bull.  U.S.Geol. 
Surv.,  No.  141,  1896,  p.  59)  a  mention  of  some  fragments  of  a  large  carapace  found  in  the 
Aquia  formation  in  Maryland,  which  he  supposed  might  belong  to  Cope's  Euclastes.     Case 


THAI.ASSEMYDIDiE. 


155 


(Geol.  Surv.  Maryland,  Eocene,  1901,  p.  97.  pi.  x,  fig.  7)  has  repeated  Dr.  Clark's  words  and 
figured  one  fragment.    The  materials  are  generically  indeterminable. 

Lytoloma  angusta  Cope. 

Plate  28,  figs.  5,  6;   text-figs.  191,  192. 

Chelone  sopita  (in  part),  Leidy,  Smithson.  Contrib.  to  Knowledge,  xiv,  1865,  p.  105,  plate  xix,  fig.  5. 
Lytoloma  angusta.  Cope,  Amer.  Naturalist,  lll,  1869,  p.  105  (nom.  nud.);    Ext.  Batrach.,  Reptilia,  Aves 

N.  A.,  1869,  p.  145,  plate  xi,  figs.  I,  lb;  Vert.  Cret.  Form.  West,  1875,  p.  257. — Hay,  Bibliog.  and 

Cat.  Foss.  Vert.  N.  A.,  1902,  p.  442. 

Cope's  first  mention  of  this  species  was  in  the  American  Naturalist,  as  quoted  above,  but 
this  mention  was  made  only  incidentally  and  what  was  said  is  not  sufficient  to  distinguish 
either  the  species  or  the  genus  from  various  other  turtles.  When  he  came  to  describe  and  figure 
the  species  Cope  stated  that  his  materials  consisted  of  three  peripheral  bones,  a  fragment  of  a 
costal,  and  a  lower  jaw.  He  says  that  the  costals  and  marginals  were  found  at  the  same  time  and 
place  as  the  jaw  and  probably  belong  to  it.  It  seems  that  he  regarded  the  peripherals  as  the 
type  of  the  species,  and  since  he  figures  only  one  of  these,  this  especially  must  be  taken  as  the 
type.  That  he  so  regarded  the  peripherals  is  evident  from  the  fact  that 
from  peripherals  alone  of  this  species  and  L.  jeanesi  he  drew  all  his  generic 
characters.  Further  proof  is  afforded  by  the  specimen  of  the  jaw  itself, 
which  bears,  in  Cope's  writing,  the  label  '"f" Lytoloma  angusta  Cope,  Bir- 
mingham, N.  J."  In  case  he  had  lookt  upon  the  jaw  as  the  type  he  could 
hardly  have  questioned  its  belonging  to  the  species.  It  is  wholly  prob- 
able that  at  least  the  figured  peripheral  and  the  costal  belong  with  the 
jaw;  and  until  it  has  been  shown  that  they  do  not,  all  may  pass  as  types. 
These  specimens  were  obtained  in  the  upper  greensand  beds  of  the  Creta- 
ceous, at  Birmingham,nearPemberton, New  Jersey.  Inasmuch  as  the  jaw 
is  labeled  by  Cope  as  coming  from  Birmingham,  it  is  probable  that  the 
specimens  were  obtained  from  some  marl-pit  between  the  two  towns. 
They  are  now  in  the  American  Museum  of  Natural  History  and  bear  the 
number  1133. 

The  figured  peripheral  (plate  28,  fig.  6)  is  said  by  Cope  to  belong  to 
the  left  side,  but  on  the  bone  itself  he  has  written  "5  R,"  from  which 
it  appears  that  he  regarded  it  as  the  fifth  of  the  right  side,  and  such  it 
seems  to  be.  It  has  a  length,  along  the  acute  free  margin,  of  67  mm.  A 
section  of  the  bone  is  triangular,  and  therefore  it  shows  three  faces  (fig. 
191).  The  visceral  face  is  22  mm.  wide,  somewhat  concave,  and  contains 
in  the  hinder  half  of  the  bone  a  deep  conical  pit  for  the  rib-end  of  the 
third  costal.  The  upper  face  is  slightly  concave  at  right  angles  with  the 
free  border,  22  mm.  wide  at  the  anterior  end,  29  mm.  at  the  posterior. 

191.  Section  through  fifth    yj^g  inferior  face  is  slightly  convex  and  32  mm.  wide  at  each  end. 

shown 'bTinte^r-  Another  peripheral  (fig.   192)  is  markt  by  Cope  "  .?2  R."     It  has  a 

rupted  line.  length  of  70  mm.,  a  thickness  at  the  visceral  face  of  16  mm.  at  one  end 

192.  Supposed    second    ^^^  j^  ^^    ^^  j|^g  Other.    The  upper  and  lower  faces  are  somewhat  con- 

ng  t  perip  era  .  ^^^  ^^  ^^^  ^^^^  border  there  is  a  broad  emargination.  At  the  bottom 
of  this  emargination  the  bone  is  28  mm.  wide.  At  one  sutural  end  the  width  is  34  mm.  There 
is  no  rib-pit  in  the  visceral  face.  The  peripheral,  supposed  by  Cope  to  be  the  fourth,  is  not 
now  with  the  other  bones. 

The  fragment  of  costal  has  a  width  of  47  mm.  near  the  sutural  border  for  the  neural.  At 
the  middle  of  the  width  the  thickness  is  10  mm.;  at  the  sutural  border  it  is  about  4  mm.  As 
stated  by  Cope,  there  is  present  the  sulcus  bounding  one  of  the  vertebral  scutes.  From  a 
comparison  with  the  figure  publisht  by  Wieland,  and  here  reproduced  (fig.  196),  this  costal  is 
believed  to  be  the  sixth  of  the  right  side.  The  outer  angle  of  the  vertebral  scute  is  placed  near 
the  hinder  sutural  border  of  the  bones,  at  a  distance  of  50  mm.  from  the  neural. 

The  lower  jaw  (plate  28,  fig.  5)  is  of  the  greatest  interest.  It  is  considerably  eroded  and 
does  not  lend  itself  well  to  illustration.    It  is  remarkable  for  the  great  length  of  the  symphysis, 


Figs.  191  and  192. — 
Lytoloma  angusta. 
Peripherals    of 
type.     Xf. 


156  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

52  mm.,  and  for  the  flatness  of  the  triturating  surfaces.  An  unimportant  part  of  the  tip  of  the 
jaw  is  broken  off.  There  was  certainly  no  upturned  beak,  such  as  there  must  have  been  in 
Rhetechelys  platyops  (Cope);  nor  was  there  a  cutting-edge  that  rose  much  above  the  triturating 
surface.  The  lower  surface  of  the  jaw  is  likewise  very  flat,  rising  abruptly  toward  the  free 
borders.  The  thickness  at  the  hinder  end  of  the  symphysis  is  18  mm.;  at  a  distance  of  25  mm. 
behind  the  tip  the  thickness  is  16  mm.  The  coronoid  process  rises  40  mm.  above  the  bottom 
of  the  ramus.  The  rami  are  thoroly  co-ossified.  There  are  no  other  bones  of  the  jaw 
present  except  the  right  coronoid,  which  is  crowded  to  the  inside  of  the  coronoid  process  of  the 
dentary. 

At  the  tip  of  the  jaw  the  borders  of  the  dentaries  diverge  at  an  angle  slightly  greater  than  a 
right  angle.  At  the  fronts  of  the  fossae  for  the  masseter  muscles  the  width  is  91  mm.;  at  the 
hinder  end  of  the  dentaries  it  is  1 10  mm.  The  fossae  just  mentioned  are  large  and  deep.  That 
part  of  each  on  the  dentary  is  40  mm.  long  and  26  mm.  high.  At  the  front  of  each  fossa  is 
a  mental  foramen.  A  line  passing  from  one  of  these  to  the  other  falls  12  mm.  in  front  of  the 
hinder  end  of  the  symphysis. 

The  fragmentary  skull  materials  described  by  Wieland  provisionally  under  the  name  of 
L.  angusta  (Amer.  Jour.  Sci.,xviii,  1904,  p.  184,  185,  figs.  I,  2)  are  here  made  the  types  of  a 
new  species.  The  carapace  which  that  author  has  also  referred  to  /..  angusta  (op.  cit.,  p. 
187,  pis.  vi-viii)  doubtfully  belongs  to  it.  In  case  the  peripheral  regarded  by  Cope  as  the 
second  really  belongs  with  the  type,  the  carapace  described  by  Wieland  certainly  does  not 
belong  to  the  species  to  which  he  has  assigned  it,  for  that  peripheral  in  the  type  has  the  border 
emarginate.  Furthermore,  the  fifth  peripheral  of  L.  angusta  does  not  resemble  closely  any 
of  those  of  the  carapace  described  by  Wieland.  It  resembles  most  nearly  the  fifth  of  Wie- 
land's  specimen,  but  differs  in  relative  length  and  width;  apparently  also  in  the  position  of 
the  pit  for  the  rib.    Only  future  discoveries  can  decide  this  point. 

The  bones  figured  by  Leidy  (as  cited  in  the  synonymy)  under  the  name  of  Chelone  sopita 
have  been  referred  by  Cope  to  Lytoloma  angusta.  They  appear  not  to  agree  with  any  species 
of  Osteopygts  in  that  they  are  much  longer  than  wide,  have  the  sulci  crossing  the  middle  of 
the  length  and  have  the  pits  well  toward  the  rear  end  of  the  bone. 

L.ytoloina  jeanesi  Cope. 

Figs.  193-195. 

Prophura  jeanesii,  CoPE,  Cook's  Geol.  of  New  Jersey,  1868  (1869),  p.  735  (nom.  nud.). 
Lytoloma  jeanesii.  Cope,  Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1869,  p.  145;   \tn.  Cret.  Form.  West, 
1875,  p.  257. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  452. 

Of  this  species  Cope  studied  what  he  regarded  as  portions  of  2  individuals.  Of  the  first, 
discovered  in  the  upper  bed  of  Cretaceous  greensand,  near  Barnesboro,  Gloucester  County, 
New  Jersey,  there  were  secured  only  the  nuchal  bone  and  the  first  peripheral.  Cope  appears 
to  have  lookt  upon  this  lot  as  the  type  of  the  species.  Where  these  bones  are  now  is  not 
known.  The  second  individual  was  obtained  in  the  same  bed  of  greensand,  at  Hornersville, 
New  Jersey.  This  specimen,  or  most  of  it,  is  now  in  the  American  Museum,  where  it  has  the 
number  1473. 

The  nuchal  bone  which  belonged  to  the  first-named  individual  was  described  by  Cope  as 
resembling  an  ordinary  peripheral,  differing  entirely  from  the  nuchal  of  Chelydra  and  Chelone. 
.The  anterior  border  appears  to  have  been  obtuse.  Its  length,  from  side  to  side,  is  not  given; 
the  width  is  stated  to  have  been  16.5  lines  (about  34  mm.).  The  nuchal  scute  which  it  bore  is 
said  to  have  been  about  18  mm.  wide.  The  bone  is  described  as  having  joined  the  first 
.peripheral  by  a  coarse  gomphosis,  the  process  coming  from  the  first  peripheral.  There  was 
also  a  sutural  border  for  union  with  the  first  neural;  but  we  are  not  told  whether  or  not  the 
nuchal  articulated  with  the  first  costals. 

The  first  peripheral  is  described  as  having  a  free  inner  border,  a  condition  showing  that  it 
did  not  articulate  with  the  first  costal.  Its  suture  with  the  nuchal  was  straight;  that  with  the 
second  peripheral  had  the  entering  angle  seen  in  Osteopygis  sopitus,  etc.  The  width  of  the  first 
peripheral  is  given  as  15.5  lines,  about  32  mm.  This  width  was  three-fifths  of  the  length, 
therefore  about  53  mm. 


thai.assemydiDj*:. 


»57 


Of  the  second  individual  examined  by  Cope  the  first  peripheral  is  at  hand  (fig.  193).  It 
has  an  obtuse  free  outer  and  an  acute  free  inner  margin.  The  thickness  near  the  proximal 
end  and  the  outer  border  is  12  mm.  At  the  hinder  end  (fig.  194)  the  thickness  is  somewhat 
less.  On  the  distal  half  of  the  bone  and  near  the  free  margin,  or  rather,  forming  the  free 
margin,  is  a  low  sharp  ridge,  at  which  the  upper  and  the  lower  surfaces  meet.  The  suture  with 
the  nuchal  is  oblique,  running  from  the  inner  border  forward  and  toward  the  midline,  then 
forward  and  outward,  then  again  forward  and  toward  the  midline.  The  end  of  the  bone  was 
somewhat  overlapt  by  the  nuchal.  The  length  along  the  free  outer  border  is  about  65  mm.; 
along  the  free  inner  border,  about  40  mm.;  from  one  extremity  to  the  other,  80  mm.  The 
greatest  width  is  35  mm.;  that  near  the  hinder  end  is  27  mm. 

The  peripheral  regarded  by  Cope  as  the  sixth  (fig.  195)  has  a  length  of  about  100  mm. 
A  part  of  the  free  border  is  broken  away.  The  bone  is  triangular  in  section,  presenting  thus 
three  faces.  The  inner  or  visceral  face  is  quite  concave  the  whole  length  and  has  in  the 
hinder  half  a  deep  conical  pit  for  the  end  of  a  rib.  The  bone  is  about  30  mm.  wide.  The  lower 
face  is  slightly  concave  and  is  30  mm.  wide.  The  upper  face  has  a  width  of  from  35  mm.  to 
38  mm.  and  it  is  nearly  plane.  According  to  the  present  interpretation,  the  bone  belongs  to 
the  right  side.  All  of  the  free  borders  are  acute,  especially  the  upper  inner,  and  in  none  of 
them  is  there  any  emargination. 


Figs.  193-195. — Lytoloma  jeanesi.     Peripherals.     X|.     No.  14.73  A.  M.  N.  H. 

193.  Right  first  peripheral. 

194.  Section  near  distal  end  of  first  peripheral. 

195.  Section  of  sixth .^  peripheral.    Pit  shown  by  interrupted  line. 

Accompanying  the  bones  above  described  is  a  fragment  of  a  costal  which  agrees  in  its 
dimensions  with  the  one  mentioned  by  Cope.  Its  width  is  90  mm.,  while  the  thickness 
thru  the  middle  of  the  width  is  II  mm.  Cope  states  that  the  costals  showed  no  sculpture. 
However,  the  present  costal  has  its  surface  broken  by  numerous  pits  of  varying  form  and  size, 
resembling  thus  closely  the  costals  of  Osteopygis  erosus.  It  is  probable  that  the  bone  belongs 
elsewhere. 

The  peripheral  described  above  as  probably  the  sixth  differs  so  much  from  the  fifth  of 
L.  angusta  that  a  distinct  species  is  clearly  indicated.  The  ratios  of  width  to  length  in  the 
two  bones  are  very  different.  The  width  of  the  peripheral  of  L.  angusta  is  contained  in  the 
length  about  two  and  a  third  times;  while  in  that  of  L.  jeanesi  the  width  is  contained  in  the 
length  three  and  a  third  times.  The  results  are  equally  decisive  in  case  both  peripherals 
should  happen  to  be  fifths  or  sixths.  It  is  wholly  probable  that  neither  of  them  can  belong 
farther  backward  in  the  series. 

The  various  measurements  of  this  bone  show  that  the  carapace  described  by  Wieland  can 

not  belong  to  L.  jeanesi. 

Lytoloma  wielandi  sp.  nov. 

Plate  zS,  figs.  7,  8;  plate  29,  fig.  i;  teit-figs.  196,  197. 

Lytoloma  angusta?,  Wieland,  Amer.  Jour.  Sci.  (4),  xviii,  1904,  p.  183,  plates  vi-viii,  text-figs.  1-3; 
Ibid.,  XX,  1905,  p.  333,  fig.  5. 

Dr.  George  R.  Wieland  has,  with  exprest  doubts,  referred  some  lower  jaws,  the  front  of  a 
skull,  and  a  carapace  of  a  Lytoloma  to  L.  angusta.  His  specimens  are  in  the  Yale  University 
collection.  The  skull  bones  were  secured  by  Professor  O.  C.  Marsh  from  the  upper  Cretaceous 
greensand  bed  at  Hornerstown,  New  Jersey.  The  carapace  came  from  Barnesboro.  It  seems 
evident  that  these  remains  do  not  belong  to  the  species  to  which  they  have  been  assigned, 
and  they  are  here  made  the  types  of  a  new  species,  named  in  honor  of  Dr.  Wieland. 


158  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

In  case  it  shall  hereafter  be  discovered  that  more  than  a  single  species  is  represented  by 
these  bones,  the  lower  jaw  figured  by  Wieland  shall  be  regarded  as  the  type  of  L.  wielandi. 

That  this  lower  jaw  is  not  identical  specifically  with  that  regarded  as  belonging  to  the 
type  of  L.  angusta  appears  from  the  following  considerations: 

(1)  The  angle  subtended  by  the  cutting-borders  of  the  jaw  of  L.  angusta  forms  at  least  a 
right  angle;    in  L.  wielandi  this  angle  is  80  degrees. 

(2)  In  L.  angusta  the  lateral  outlines  of  the  jaw  continue  outward  and  backward  in  nearly 
straight  lines  to  the  mental  foramina;  in  L.  wielandi  the  borders  are  deflected  more  nearly 
backward  at  a  considerable  distance  in  front  of  these  foramina. 

(3)  In  L.  angusta  a  line  drawn  from  one  foramen  to  the  other  falls  12  mm.  in  front  of  the 
hinder  end  of  the  symphysis;   in  L.  wielandi  it  falls  at  the  hinder  end  of  the  symphysis. 

(4)  In  L.  angusta  the  descent  from  the  summit  of  the  coronoid  is  much  more  abrupt  than  in 
the  other  species  considered.  In  the  former  species  the  height  of  the  coronoid  process  is  77 
per  cent,  of  the  length  of  the  symphysis;  in  the  new  species,  only  60  per  cent. 

(5)  The  tip  of  the  jaw  of  L.  wielandi  appears  to  have  been  more  upturned,  more  acute, 
and  in  every  way  more  beak-like  than  in  L.  angusta. 

DiflFerences  so  great  as  indicated  above  in  two  jaws  whose  symphyses  are  respectively  52 
mm.  and  42  mm.  can  hardly  be  attributed  to  differences  in  age  or  sex.  At  least,  so  great 
differences  do  not  appear  in  a  number  of  jaws  of  the  loggerhead  turtle,  to  which  the  jaws  of 
Lytoloma  have  great  resemblances.  In  a  huge  skull  of  the  loggerhead,  the  length  of  which 
from  snout  to  occipital  condyle  is  230  mm.,  the  line  joining  the  mental  foramina  falls  at  the 
hinder  end  of  the  symphysis,  while  it  falls  only  12  mm.  behind  the  symphysis  in  a  young 
specimen  whose  skull  is  only  130  mm.  long.  As  to  the  lateral  outlines  of  jaws,  the  elevation  of 
the  coronoids,  and  the  form  of  the  tip,  there  is  not  much  difference  among  specimens  of  middle 
and  large  sizes.  The  angle  subtended  by  the  outlines  of  the  anterior  portions  of  the  lower 
jaws  of  Caretta  may,  however,  vary  as  much  as  in  the  case  of  L.  angusta  and  L.  wielandi. 

The  width  of  the  jaw  forming  the  type  of  L.  wielandi,  taken  at  the  mental  foramina,  is 
66  mm.;  taken  at  the  hinder  ends  of  the  dentaries,  75  mm.  The  length  of  the  symphysis  is 
42  mm.    The  greatest  thickness  at  the  symphysis  is  1 1  mm. 

The  front  of  the  skull  figured  by  Wieland  agrees  in  size  and  in  the  angle  made  by  the 
borders  of  the  upper  jaws  with  the  lower  jaw  just  described.  A  comparison  made  with  the 
jaw  of  the  loggerhead  indicates  that  the  skull  of  which  it  formed  a  part  had  a  length  of  about 
156  mm.  Seen  from  above  or  below,  it  resembles  considerably  the  same  part  in  the  log- 
gerhead. Seen  from  the  side,  the  tip  of  the  snout  is  much  more  deprest  than  in  the  loggerhead, 
a  condition  due  probably  to  the  little-developt  cutting-edge  of  Lytoloma.  Plate  28,  fig.  7,  rep- 
resents Wieland's  type  skull  seen  from  above;  plate  28,  fig.  8,  as  seen  from  below;  and  plate 
29,  fig.  I,  as  seen  from  behind.  These  figures  are  reproduced  from  drawings  made  for  Dr. 
Baur  in  1888. 

The  orbit  was  large.  The  prefrontals  joined  along  the  midline  for  a  distance  of  at  least 
12  mm.  and  to  a  line  crossing  the  skull  considerably  behind  the  fronts  of  the  orbits.  In  Rhe- 
techelys  platyops  (Cope)  the  prefrontals  were  parted  by  the  frontals  to  a  line  considerably  in 
front  of  the  orbits. 

The  external  nasal  opening  has  its  transverse  and  its  longitudinal  dimensions  each  20  mm. 
The  snout  as  seen  from  above  is  not  acuminate,  as  it  was  in  Rhetechelys  platyops. 

The  vomer  appears,  as  in  Rhetechelys  platyops,  to  have  wholly  separated  the  horizontal 
plates  of  the  palatines.  It  has  a  length  of  33  mm.  and  a  width  of  20  mm.  The  width  of  the 
perpendicular  plate  of  the  vomer,  between  the  narial  passages,  is  1 1  mm.  The  choanae  are 
thrown  well  backward,  but  it  is  doubtful  whether  they  were  pushed  backward  as  far  as  they 
were  in  R.  platyops,  to  a  line  joining  the  hinder  borders  of  the  orbits. 

There  is  no  certainty  that  the  carapace  described  by  Dr.  Wieland  belongs  to  the  present 
species,  and  it  is  so  referred  only  because  it  seems  to  belong  neither  to  L.  angusta  nor  L. 
jeanesi. 

This  carapace  (fig.  196)  was  received  by  Prof.  O.  C.  Marsh,  May  I,  1869,  it  having  been 
sent  to  him  from  the  upper  greensand  bed  of  the  Cretaceous,  near  Barnesboro,  New  Jersey. 

The  estimated  length  of  the  carapace  is  580  mm.;  the  greatest  breadth,  530  mm.  In 
general,  it  resembles  the  carapace  of  the  loggerhead,  but  it  is  far  less  pointed  behind,  a  con- 


THAI.ASSEMYDID^. 


159 


dition  showing  that  the  turtles  of  this  genus  had  not  yet  become  seafarers.  At  Dr.  Wieland's 
disposal,  belonging  to  this  specimen,  were  wholes  or  parts  of  the  third,  fourth,  fifth,  and  sixth 
neurals,  wholes  or  parts  of  two  suprapygals,  wholes  or  parts  of  all  the  costals  of  the  right  side 
and  of  most  of  those  of  the  left  side,  wholes  or  parts  of  all  the  peripherals  of  the  left  side  behind 
the  third  and  of  most  of  those  of  the  right  side  behind  the  third,  and  a  portion  of  the  pygal. 
The  nuchal  and  the  three  anterior  pairs  of  peripherals  were  missing. 

The  neurals  are  hexagonal,  with  the  broader  end  forward,  and  nearly  as  wide  as  long. 
The  third  is  44  mm.  long  and  44  mm.  wide;  the  fifth  41  mm.  long  and  41  mm.  wide;  the  sixth 
41  mm.  long  and  34  mm.  wide.    They  are  each  6  mm.  or  7  mm.  thick.    The  anterior  suprapygal 


Figs.  196  and  197. — Lytoloma  wielandi.     Carapace  and  sections  of  peripherals  of  type. 

196.  Carapace.     X}.    After  W'iel and.    f.  p.  i,  c.  p.  6,  c. />.  8,  first,  siith,  and  eighth  costals;  c.  j.  i,  c.  s.  4,  first  and 

fourth  costal  scutes;  /,  lateral  fontanels;  m.  5.  5,  m.  5.  9,  m.  j.  12,  fifth,  ninth,  and  twelfth  marginal  scutes; 
n.  3,  n.  6,  third  and  sixth  neural  bones;  nu.  p,  nuchal  bone;  nu.i,  nuchal  scute;  per.  2,  per.  9,  per. 
II,  second,  ninth,  and  eleventh  peripheral  bones;  py,  pygal;  spy.  2,  spy.'i,  second  and  third  suprapygal 
bones;  v.  j.  1 ,  r.  i.  2,  first  and  second  vertebral  scutes. 

197.  Sections  through  middle  of  length  of  peripherals.     Xj.    The  numeral  on  each  indicates  the  position  of  the 

bone.    The  dotted  line  indicates  the  pit.    py,  section  along  middle  of  pygal. 

is  37  mm.  long  and  80  'mm.  wide;  the  posterior,  60  mm.  long  and  perhaps  80  mm.  wide.    The 
posterior  articulated  narrowly  with  the  pygal. 

The  costals  varied  in  width  from  50  mm.  to  60  mm.  It  is  evident  that  the  first  costals 
articulated  with  the  nuchal  at  its  outer  extremities.  Cope  states  that  the  nuchal  of 
L.  jeanesi  articulated  with  the  first  neural,  but  he  says  nothing  about  the  articulation  with 
the  first  costals.  The  latter  species  possest  a  nuchal  extremely  narrow,  little  wider  than 
the  first   peripheral,  and  therefore  quite   unlike  that  shown   in  Dr.   Wieland's   restoration. 

However, as  Dr. Wieland's  specimen  lackt  the  nuchal  and 
the  anterior  peripherals,  we  do  not  know  their  structure 
and  connections. 

The  eighth  costal  had  its  rib-end  thrown  back,  so  as 
to  enter  a  pit  in  the  eleventh  peripheral,  a  feature  common 
in  the  Cheloniidae.  As  in  the  Cheloniida;,  too,  there  were 
extensive  fontanels  between  the  distal  ends  of  the  costals 
and  the  peripherals. 


Width. 

Peripheral. 

Length. 

Upper  face. 

Inner  face. 

4 

55 

»S 

24 

6 

71 

43 

ii 

8 

go 

56 

15 

10 

75 

60 

•3 

Vertebral. 

Length. 

Width. 

2 

3 

4 

loo 

no 
.14 

•45 

•35 
ISO 

l6o  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

The  peripherals  have  each  three  faces,  an  inner  or  visceral,  a  superior,  and  an  inferior. 
Each  of  them,  from  the  fourth  to  the  ninth  inclusive,  has  a  pit  for  the  reception  of  the  end  of 
a  rib.  Fig.  197  from  Wieland  represents  sections  of  these  peripherals.  It  will  be  observed  that 
they  grow  broader  and  thinner  from  the  front  of  the  carapace.  The  dotted  line  in  each  repre- 
sents the  depth  of  the  pit.  The  table,  p.  159,  gives  the  dimensions  of  some  of  the  peripherals. 
Dr.  Wieland  has  described  certain  ossicles  intercalated  between  the  peripherals  along  the 
free  borders  of  his  specimen.  He  suggests  that  these  are  a  part  of  the  disappearing  osteo- 
dermal  covering  of  primitive  turtles. 

The  carapace  was  covered  with  horny  scutes,  which  have  left  distinct  impressions  of  the 
sulci  on  the  various  bones.  There  were,  so  far  as  appears,  5  vertebral  scutes,  4  pairs  of  costals, 
and  probably  12  pairs  of  marginals  and  a  nuchal.     The  vertebrals  are  strongly  angulated 

laterally  where  the  sulci  running  down  between  the  costals  are 
given  off.  The  table  herewith  shows  the  dimensions  of  three 
vertebral  scutes. 

How  high  on  the  costal  bones  the  marginal  scutes  rose  can 
not  be  determined. 

There  were  preserved  with  this  carapace  some  fragments  of 
the  plastron,  but  not  enough  to  permit  a  restoration  of  it.  Wie- 
land regards  the  plastron  as  having  been  more  reduced  than  it 
was  in  Osteopygis,  but  otherwise  much  like  it.  Small  pits  in  the  hinder  half  of  the  lower 
inner  free  margin  of  the  fourth  peripheral  show  that  the  hyoplastron  extended  forward  only 
to  it.    There  are  no  pits  to  show  how  far  backward  the  hypoplastron  extended. 

The  reasons  for  regarding  this  carapace  as  distinct  from  that  of  L.  angusta  are  presented 
under  the  latter  species. 

Genus  ERQUELINNESIA  DoUo. 

Pachyrhynchus,  DoLLO,  Bull.  Mus.  roy.  d'Hist.  nat.  Belgique,  4,  1886,  p.  130  (preoccupied). 
Erquelinnesia,  DoLLO,  Geol.  Magazine  (3),  iv,  1887,  p.  393. 

Skull  resembling  that  of  Caretta  caretta,  but  more  elevated  and  descending  more  rapidly 
in  front  of  the  orbits.  Palate  flat,  bounded  by  low  cutting-edges,  and  extending  backward  to 
the  hinder  half  of  the  roof  of  the  mouth.  Choanae  in  the  hinder  half  of  the  roof  of  the  mouth, 
their  anterior  boundary  formed  by  the  palatines,  which  have  met  behind  the  palatal  plate  of 
the  vomer.    Lower  jaw  not  beakt.    Shell  resembling  that  of  Caretta,  but  more  rounded  behind. 

Type:    Erquelinnesia  gosseleti  Do\\o  =  Chelone  crassicostata  Owen. 

For  the  structure  of  the  palate  of  this  genus  the  reader  is  referred  to  Mr.  R.  Lydekker's 
figure  of  Lytoloma  crassicostaium  (Proc.  Zool.  Soc,  London,  1889,  plate  vi).  This  figure 
shows  that  the  choanae  are  placed  in  the  posterior  third  of  the  cranium  and  that  the  palatal 
plates  of  the  palatine  bones  meet  each  other  in  the  midline  behind  the  vomer  and  beneath  the 
narial  passages.  In  the  article  accompanying  this  plate  Mr.  Lydekker  states  that  Dr.  Dollo's 
Erquelinnesia  gosseleti  is  identical  specifically  with  Owen's  Chelone  crassicostata.  For  refer- 
ence to  other  views  of  the  skull  and  to  figures  of  the  carapace  of  this  species,  and  to  the 
literature,  the  reader  is  referred  to  Lydekker's  Catalogue  of  Fossil  Reptiles,  part  iii,  1889, 
page  60.  On  page  26  of  this  work  is  presented  a  figure  of  the  humerus  of  E.  crassicostata. 
It  is  evident  that  the  members  of  the  genus  had  not  yet  developt  a  limb  adapted  for  life  on 
the  open  sea. 

The  following  species  is  assigned  provisionally  to  Erquelinnesia  on  account  of  the  great 
length  of  the  symphysis  of  the  lower  jaw.  This  seems  to  indicate  that  the  choanae  were  located 
far  toward  the  rear  of  the  skull,  so  far  that  the  palatines  must  have  met  behind  the  vomer.  It 
is  probable  that  in  Osteopygis  the  choanae  were  not  removed  so  far  toward  the  rear  of  the  skull. 

Erquelinnesia  molaria  sp.  nov. 
Figs.  198,  199. 

This  species  is  based  on  a  lower  jaw  which  is  found  in  the  collection  of  the  Academy  of 
Natural  Sciences  of  Philadelphia.  It  is  labeled  as  being  Lytoloma  platyops,  as  having  been 
presented  by  Rev.  L.  H.  Lighthipe,  and  as  having  been  secured  at  Birmingham,  New  Jersey. 
It  has,  therefore,  been  collected  from  the  upper  bed  of  the  Cretaceous  greensand. 


THALASSEMYDIDiS. 


l6l 


This  jaw  (figs.  198,  199)  is  remarkable  for  the  great  length  of  the  symphysis,  this  length 
considerably  exceeding  that  of  Lytoloma  angusta.  The  width  of  the  jaw,  at  the  mental  fora- 
mina, is  88  mm.;  at  the  hinder  ends  of  the  dentaries,  100  mm.,  dimensions  almost  exactly  those 
of  the  jaw  belonging  with  the  type  of  L.  angusta.  The  length  of  the  symphysis  is  65  mm.,  that 
of  the  jaw  of  L.  angusta  being  52  mm.  In  the  latter  species  the  hinder  end  of  the  symphysis 
falls  12  mm.  behind  the  line  joining  the  mental  foramina;  in  E.  molaria  it  falls  22  mm.  behind 
that  line.  The  triturating  surface  is  flat  to  near  the  inconspicuous  cutting-edges,  to  which 
it  ascends.  The  lower  surface  of  the  jaw  also  is  flat,  ascending  rather  abruptly  to  the  cutting- 
edges.  Anteriorly  the  lower  surface  approaches  gradually  the  upper  surface  at  the  sharp- 
edged  tip  of  the  jaw.  The  outline  of  this  tip 
is  truncated  and  about  20  mm.  wide.  The 
coronoid  process  rises  about  33  mm.  above  the 
bottom  of  the  ramus,  and  the  descent  from  it 
toward  the  tip  of  the  jaw  is  gradual.  The 
masseter  fossa  is  large. 

The  greatest  thickness  of  the  triturating 
surface  is  near  the  hinder  end  of  the  symphysis. 
The  angle  between  the  borders  of  the  jaw,  in 
front,  is  considerably  more  than  a  right  angle. 
This  jaw  can  not  be  that  of  Rhetechelys 
platyops  (Cope)  for  at  least  two  reasons.  The 
angle  between  the  lateral  borders  is  too  great 
to  fit  the  upper  jaw  oi  R.  platyops.  The  type 
of  the  latter  species  belonged  to  an  individual 
about  twice  as  large  as  the  possessor  of  the  jaw 
here  described;  and,  if  they  belonged  to  the 
same  species,  the  angle  of  the  jaw  of  the  type  of 
R.  platyops  ought  to  be  the  larger.  Again,  in  case 
the  present  jaw  had  belonged  to  R.  platyops, 
the  hinder  end  of  the  symphysis  would  have 
fallen  a  distance  behind  the  choanae  equal  to  the 
length  of  the  palatal  plate  of  the  vomer.  The 
results  of  this  would  have  been  that  a  large  part 
of  the  triturating  surface  of  the  lower  jaw  would 
have  had  no  surface  to  oppose  it  and  it  would 
have  been  applied  against  the  choanae,  thus  interfering  with  breathing. 

From  both  Lytoloma  angusta  and  L.  wielandi  this  species  differs  in  the  greater  length  of 
the  symphysis  and  in  the  smaller  angle  between  the  borders  of  the  jaw. 

Genus  RHETECHELYS  nov. 

Skull  broad  and  deprest.  Temporal  region  widely  rooft  over.  Triturating  surface  of  upper 
jaw  broad,  involving  the  maxillae,  the  palatines,  and  the  vomer.  Choanae  near  the  middle  of 
the  roof  of  the  mou  h;  the  palatines  not  meeting  behind  the  vomer.  A  pit  between  the  pre- 
maxills  for  the  reception  of  the  upturned  beak  of  the  lower  jaw.    Shell  and  limbs  unknown. 

Type :    Euclastes  platyops  Cope. 

This  genus  diflPers  from  the  species  of  Lytoloma  (to  which  genus  it  has  been  referred  since 
the  discovery  that  the  name  Euclastes  is  preoccupied)  in  having  had  the  tip  of  the  lower  jaw 
furnisht  with  an  upturned  beak.  The  existence  of  this  is  inferred  from  the  presence  of  a  deep 
depression  between  the  palatal  plates  of  the  premaxillae  and  an  interruption  of  the  bone. 
Similar  conditions  are  found  in  the  skull  of  Macrochelys.  Osteopygts,  Lytoloma,  and  Erquelin- 
nesla  all  have  lower  jaws  with  broad,  flat  triturating  surfaces,  but  m  none  of  them  do  we  hnd 

any  traces  of  a  beak.  ■      ■      1  in  1  j 

The  only  known  species  of  the  genus  was  a  large  and  powerful  animal,  whose  skull  equaled 
in  size  that  of  the  largest  specimens  of  the  living  loggerhead. 
II 


Figs.  198  and  igg. — Erquelinnesta   molaria. 
Lower  jaw  forming  the  type.     X§. 

198.  Upper  view  of  jaw.  199.  Side  view  of  jaw. 


l62  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

Dr.  W.  B.  Clark  has  referred  provisionally  (Johns  Hopkins  Univ.  Circ,  xv,  1895,  No.  4; 
Bull.  U.  S.  Geol.  Surv.,  141,  p.  59)  some  fragments  of  a  large  turtle  to  Euclastes.  One  of  these 
fragments  has  been  again  mentioned  and  figured  by  Dr.  Case  in  the  Eocene  volume  of  the 
Geological  Survey  of  Maryland  (p.  97,  plate  x,  fig.  7).    The  fragment  is   not  susceptible  of 

generic  determination. 

Rhetechelys  platyops  (Cope). 

Plate  29,  figs.  2,  3. 

Euclastes  platyops,  CoPE,  Proc.  Acad.  Nat.  Sci.  Phila.  1867,  p.  41;  Cook's  Geo!.  New  Jersey,  1868 
(1869),  p.  735;  Amer.  Naturalist,  in,  1869,  p.  89;  Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1869,  p. 
149,  plates  vi,  vii,  fig.  9;    Vert.  Cret.  Form.  West,  1875,  p.  259. 

Lytoloma  platyops,  Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  442. — ^WlELAND,  Amer.  Jour.  Sci. 
(4),  xviii,  1904,  p.  185. 

FPropleura  sopita,  CoPE,  Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1869,  p.  140  (Harrisonville  specimen). 

All  that  we  know  at  present  regarding  this  species  is  what  is  to  be  derived  from  the  type 
skull.  This  is  in  the  collection  of  the  Academy  of  Natural  Sciences  at  Philadelphia.  It  was 
found  in  a  coarse  granular  limestone,  at  HurfFsville,  Camden  County,  New  Jersey.  This 
deposit  belongs  to  the  Upper  Cretaceous  and  was  regarded  by  Cope  as  equivalent  to  the  Fox 
Hills  group.    The  species  formed  the  type  of  Cope's  genus  Euclastes,  a  preoccupied  name. 

The  skull  was  a  large  one,  the  total  length  being  estimated  by  Cope  as  11  inches,  about 
280  mm.;  but  this  must  have  included  the  supraoccipital  process.  At  any  rate,  the  length  was 
equal  to  that  of  the  largest  specimens  of  Caretta.  The  occipital  condyle  is  missing,  but  the 
length  from  the  premaxillae  to  this  condyle  must  have  been  close  to  200  mm.,  perhaps  a  little 
more.  The  width,  a  short  distance  behind  the  orbits,  is  220  mm.  From  this  widest  part  the 
aiteral  outlines  converge  rapidly  to  the  pointed  snout.  Beneath  the  orbit  the  outlines  are 
slightly  concave.  The  angle  included  between  the  borders  of  the  maxillae  is  somewhat  less 
than  a  right  angle.  The  roof  is  broad  and  deprest,  the  frontal  region  being  flat.  The  slope 
from  the  rear  to  the  nasal  opening  is  only  slightly  sinuous.  There  is  no  such  sudden  descent 
from  the  orbits  to  the  premaxillae  as  we  see  in  the  species  oi  Glossochelys.  The  temporal  region 
was  broadly  rooft  over,  as  in  Caretta,  but  extended  backward  still  further.  The  various  bones 
appear  to  have  been  disposed  about  as  in  the  living  genus  mentioned. 

The  orbits  look  outward,  forward,  and  upward.  The  upward  inclination  exceeds  that  of 
Caretta.  The  greatest  diameter  of  the  orbit  is  63  mm.  The  least  interorbital  width  is  about 
50  mm.  The  frontal  bones  are  more  produced  forward  than  in  Caretta,  their  suture  measuring 
55  mm.  They  are  excluded  from  the  rim  of  the  orbits  by  the  union  of  the  postfrontals  with  the 
prefrontals.    The  latter  bones  meet  along  the  midline  a  distance  of  12  mm. 

The  nasal  opening  has  a  width  of  30  mm.  It  looks  forward  and  strongly  upward.  As  in 
other  Cryptodira,  the  prefrontals  send  downward  on  each  side  a  column  of  bone  to  the  vomer. 

The  roof  of  the  mouth  resembles  in  general  that  oi  Caretta,  but  there  are  important  differ- 
ences. The  cutting-edges  of  the  maxillae  are  only  feebly  developt,  descending  but  little  below 
the  level  of  the  grinding  surface.  This  surface  is  formed  by  the  union  of  the  palatal  plates  of 
the  premaxillae,  maxillae,  vomer,  and  palatines.  It  extends  backward  a  distance  of  nearly 
100  mm.  from  the  premaxillae.  It  is  somewhat  concave  on  each  side  of  the  vomer  and  in  the 
premaxillary  region.  In  the  roof  of  the  mouth  the  maxillae  are  each  41  mm.  wide;  the  palatines 
about  26  mm.    The  vomer  is  50  mm.  long  and  28  mm.  wide. 

The  occipital  condyle  is  missing,  but  the  choanae  fall  within  the  anterior  half  of  the  length 
to  the  roof  of  the  mouth.  They  are  bounded  laterally  by  the  palatines  and  anteriorly  by  the 
vomer,  the  edge  of  this  being  98  mm.  behind  the  tip  of  the  snout.  They  are  thus  quite  different 
from  those  of  the  species  of  Erqueltnnesia.  The  palatal  openings  of  the  temporal  fossae  are 
broader  than  long.    The  borders  of  the  pterygoids  were  strongly  emarginated. 

Between  the  anterior  ends  of  the  premaxillae  is  a  perforation  supposed  to  be  for  the  recep- 
tion of  a  hook  on  the  lower  jaw,  as  in  Macrochelys. 

Professor  Cope  supposed  that  the  whole  length  of  the  animal  which  possest  this  skull 
was  a  little  over  6J  feet;  but  it  is  not  safe  to  estimate  the  size  of  a  turtle  from  the  size  of  the 
head.  Nevertheless,  it  must  have  been  a  large  and  formidable  brute.  Probably  it  haunted 
the  coasts  of  the  Cretaceous  seas,  betaking  itself  at  times  to  some  distance  from  the  shore. 


THALASSEMYDID^.  163 

Its  food  has  been  supposed  to  have  been  hard-shelled  animals,  such  as  moUusks,  which  were 
crusht  between  its  mill-stone-Iike  jaws.  The  possession  of  a  hookt  beak  like  that  of  the 
alligator-snapper  suggests,  however,  that  the  animal  may  have  been  accustomed  to  the  captur- 
ing of  a  more  active  prey,  such  perhaps  as  fishes. 

Cope,  as  cited  in  the  synonymy  above,  referred  certain  bones  obtained  at  Harrisonville, 
Salem  County,  New  Jersey,  to  Propleura  sopita.  These  consisted,  as  he  says,  of  2  peripheral 
bones,  part  of  a  costal,  half  a  femur,  and  2  phalanges.  This  lot  is  in  the  American  Museum  and 
is  found  to  include  three  peripherals,  a  fragment  of  a  costal,  and  the  distal  end  of  a  femur. 
The  foot  bones  are  missing.  The  number  is  2361.  These  bones  quite  certainly  do  not  belong 
to  Osteopygis.  In  all  specimens  known  to  belong  to  the  latter  genus  the  pit  for  the  rib-end  is 
placed  at  the  middle  of  the  length  of  the  peripheral  or  not  far  behind  it.  Only  in  the  tenth 
peripheral  is  it  placed  close  to  the  hinder  end  of  the  peripheral.  In  the  bones  of  the  Harrison- 
ville specimen  the  pit  is  placed  far  backward.  Since  Rhctechelys  platyops  was  found  in  the 
same  limestone  not  many  miles  distant,  the  bones  found  at  Harrisonville  are  referred  provis- 
ionally to  the  species  just  named. 

One  of  the  peripherals  appears  to  be  the  left  first.  Its  length  is  85  mm.;  its  height  48  mm.; 
the  thickness  of  the  obtuse  free  border,  19  mm.  in  front.  The  articulation  with  the  first  costal 
was  not  strong  and  apparently  only  along  the  anterior  end  ot  the  bone.  It  is  not  certain  that 
any  part  of  the  first  vertebral  scute  descended  on  this  peripheral.  Another  peripheral  is  prob- 
ably the  left  fifth.  The  anterior  end  is  broken  off,  but  the  length  must  have  been  about  1 10  mm. 
From  the  hinder  end  to  the  intermarginal  sulcus  is  60  mm.  The  height  of  the  upper  face,  at 
the  sulcus,  is  62  mm.;  the  lower  face,  53  mm.;  the  inner  face,  50  mm.  The  pit  is  in  the  hinder 
third  of  the  bone.  The  upper  face  is  slightly  concave;  the  lower  slightly  convex;  the  inner 
concave.  The  remaining  peripheral  is  probably  the  seventh.  Cope  regarded  it  as  the  eighth. 
Most  of  the  outer  border  is  broken  away.  The  length  is  95  mm.;  the  height,  79  mm.;  the 
thickness  of  the  costal  border,  28  mm.  in  front,  24  mm.  behind.  The  upper  surface  is  some- 
what concave;  the  lower,  convex;  The  circular  rib-pit  is  almost  wholly  in  the  hinder  third 
of  the  inner  face.  The  piece  of  costal  is  7  mm.  thick  at  the  sutural  border.  All  these  bones 
are  smooth,  but  markt  by  vascular  grooves.  The  width  of  the  femur  at  the  distal  end  is  45 
mm.    The  diameter  of  the  shaft  is  19  mm.     The  bone  was  considerably  bent. 

FamUy  TOXOCHELYID.«;  Baur. 

Skull  somewhat  deprest.  Temporal  region  extensively  rooft.  Quadrate  notcht  for  the 
columella.  Choan^  situated  well  forward;  not  underfloored  by  the  palatines.  Palatines 
extending  forward  to  the  vomers  and  forming  the  outer  boundaries  of  the  choanae.  Carapace 
with  eleven  pairs  of  peripherals,  in  addition  to  the  nuchal  and  pygal.  Nuchal  not  furnisht  with 
costiform  processes.  Epidermal  shields  present.  Plastron  loosely  articulated  with  the  carapace, 
not  extending  forward  to  the  third  peripheral  and  backward  hardly  to  the  eighth.  Fore  foot 
with  at  least  2  claws;  the  phalanges  furnisht  with  condyles;  the  limb  as  a  whole  resembling 
that  of  the  Trionychidae. 

Genera  2,  Toxochelys  and  Porthochelys.  With  these  may  be  included  provisionally  the 
insufficiently  known  genus  Cynocercus. 

The  writer  excludes  the  members  of  this  family  from  the  Cheloniidx  especially  because  the 
fore  limb  had  not  yet  become  develop!  into  a  flipper  like  that  of  the  modern  sea-turtles.  The 
humerus  offers  scarcely  an  approach  to  that  of  the  sea-turtles.  Nor  was  the  hinder  limb 
nearly  so  much  reduced  as  in  the  latter.  The  limbs  were  probably  greatly  like  those  of  the 
Trionychidse.  That  the  anterior  limbs  were  not  habitually  employed  in  swimming  appears  to  be 
shown  by  the  fact  that  the  shell  was  not  excavated  over  these  limbs  as  it  is  in  the  Chelonndae. 

Genus  TOXOCHELYS  Cope. 

Skull  longer  than  broad.    No  nasal  bones.    Carapace  with  large  lateral  fontanels.    None 
of  the  peripherals  in  contact  with  the  disk  of  the  carapace.     Midline  with  prominent  carma 
rising  at  intervals  into  tubercles,  some  of  which  are  distinct  bones.     Tail  with  a  series  ot 
comprest  tubercles  above.     Plastron  with  median  and  lateral  fontanels. 

Type:    Toxochelys  latiremis  Cope. 


164  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

The  known  species  of  this  genus,  7  in  number,  are  from  the  Niobrara  deposits  of  Kansas. 
All  these  species  except  T.  hauri  Wieland  are  based  on  parts  of  the  skull ;  and  this  portion 
of  the  skeleton  is  more  commonly  found  than  even  the  carapace,  a  rare  circumstance  in  the 
case  of  fossil  turtles.  However,  the  greater  part  of  the  shell  and  limbs  is  known  from  two  or 
three  of  the  species. 

From  studies  made  on  this  genus  some  years  ago  (Field  Columb.  Mus.  Pubs.,  Zool.  ser. 
I,  1896,  p.  loi)  the  writer  concluded  that  the  position  of  this  genus  is  near  the  Cheloniidae,  but 
with  evident  relationships  to  the  Chelydridae,  constituting  a  distinct  family,  which  is  to  be 
called,  as  Baur  has  proposed,  Toxochelyidas.  This  conclusion  has  been  confirmed  by  more 
recent  investigations  made  by  Case,  Wieland,  and  the  present  writer.  The  resemblances  to 
Chelydra  are  to  be  found  especially  in  the  anterior  portion  of  the  skull,  in  the  structure  of  the 
carapace,  in  the  humerus  and  femur,  and  in  the  tuberculated  tail. 

The  roof  of  the  mouth  is  practically  identical  with  that  oi  Chelydra  except  that  the  palatine 
extends  forward  to  articulate  with  the  vomer  in  front  of  the  choanae.  The  masticatory  surfaces 
of  the  two  are  equally  flat,  the  cutting-edges  of  the  maxilla  are  low  in  both,  the  choanae  are 
placed  well  forward  and  are  not  underfloored  by  processes  from  the  palatines;  and  there  are 
in  both  genera  large  palatine  foramina.  On  the  other  hand,  as  in  the  Cheloniidae,  the  tympanic 
cavity  has  not  yet  entered  the  squamosal  bone,  the  notch  in  the  hinder  face  of  the  quadrate 
remains  open,  and  the  back  of  the  skull  is  extensively  rooft  over  by  the  parietal,  postfrontal, 
and  squamosal  bones.  As  regards  the  carapace,  it  is  evident  that  the  nuchal  resembles 
more  that  of  the  Cheloniidae,  it  having  had  no  such  long  costiform  processes  as  we  find  in  the 
Chelydridae.  Again  in  the  presence  of  a  surface  for  articulation  with  the  spine  of  the  eighth 
cervical,  as  determined  by  Wieland,  the  nuchal  resembles  more  that  of  the  Cheloniidae.  There 
were  1 1  peripherals,  as  in  Chelydra  and  most  Cheloniidae.  The  costal  plates  were  less  developt 
than  in  the  Chelydridae,  even  less  than  in  any  living  Cheloniidae,  so  that  there  are  extensive 
fontanels  at  the  sides  of  the  carapace.  The  elements  in  the  midline  appear  to  have  resembled 
more  those  of  Chelydra,  but  there  were  peculiarities.  There  was  a  prominent  carina,  which  at 
intervals  rose  into  comprest  tubercles.  The  latter  were  distinct  bones,  which  rested  on  the 
contiguous  portions  of  two  neurals  or  suprapygals.  The  first  rested  on  the  first  neural;  the 
second,  on  the  second  and  third;  the  third,  on  the  fourth  and  fifth;  the  fourth,  apparently 
on  the  seventh  and  eighth  or  on  the  eighth  peripheral  and  the  first  suprapygal.  If  the  fourth 
was  placed  on  the  seventh  and  eighth  neurals  a  fifth  tubercle  rested  on  the  second  suprapygal. 
Wieland  has  named  these  ossicles  "epineural  spines,"  but  they  are  hardly  to  be  thus  homol- 
ogized  with  the  epineural  bones  of  fishes.  They  were  continued  backward  on  the  upper 
surface  of  the  tail  as  a  series  such  as  we  find  on  the  tail  of  Chelydra.  The  position  of  all  these, 
except  the  most  anterior,  was  described  and  figured  by  the  writer  in  1898  (Amer.  Naturalist, 
XXXII,  p.  936,  fig.  2).  Dr.  Case  was  the  first  to  observe  the  presence  of  one  of  these  bones. 
Wieland  in  1905  (Amer.  Jour.  Sci.,  xx,  p.  331)  describes  a  small  bone  on  the  first  neural 
which  probably  represents  the  first  of  this  series  of  ossicles.  Wieland  in  1896  (Amer.  Jour. 
Sci.,  II,  p.  400)  suggested  that  Archelon  may  have  borne  a  series  of  dorsal  spines;  but  as  those 
spines  were  believed  to  be  horny  and  their  existence  only  hypothetical,  their  discovery  has 
nothing  to  do  with  that  of  the  bony  spines.  The  writer  has  elsewhere  presented  his  reasons 
for  believing  that  these  tubercles  represent  the  original  dermal  skeleton  of  the  Testudines, 
now  retained  only  by  Dermochelys  (Amer.  Naturalist,  xxxil,  1898,  p.  929). 

The  writer  presents  here  a  description  and  figures  (plate  30,  figs,  i,  2)  of  a  portion  of  a 
carapace  belonging  to  an  undetermined  species  of  this  genus,  remains  which  were  collected 
by  Mr.  H.  T.  Martin  in  Gove  County,  near  Monument  Rock,  Kansas.  Since  this  carapace 
was  not  accompanied  by  any  part  of  the  skull,  it  was  not  possible  to  identify  it  specifically. 

The  specimen  furnishes  15  peripherals,  some  fragments  of  costals,  and  a  series  of  median 
elements,  of  which  2  appear  to  be  suprapygals.  The  median  line  of  the  carapace  was  occupied 
by  a  strong  and  sharp  keel.  Anteriorly  the  right  and  left  sides  of  this  keel  make  about  a  right 
angle  with  each  other,  but  posteriorly  they  meet  at  a  smaller  angle,  so  that  the  keel  is  high  and 
sharp.  At  intervals  the  keel  rises  into  comprest  tubercles.  These  were  in  all  cases  originally 
distinct  bones,  but  most  of  them,  especially  posteriorly,  have  become  co-ossified  with  the 
supporting  bones.  The  first  neural  appears  to  be  wanting,  together  with  the  nuchal.^  There 
is  present  i  neural  which  does  not  furnish  satisfactory  contact  with  any  of  the  others.    There 


TOXOCHELYID^. 


165 


are  3  others  joined  in  their  natural  relation,  and  3  more  joined  together  and  the  hinder- 
most  united  with  the  suprapygals.  The  single  neural  must  belong  in  front  of  all  the  others. 
It  can  not  be  the  first  one,  because  it  is  too  thick  in  front  for  the  nuchal,  in  case  this  was  as 
thin  behind  as  in  the  genus  generally;  also  because  it  is  not  crost  by  the  sulcus  separating  the 
first  from  the  second  vertebral  scute.  It  can  hardly  be  anything  else  than  the  second  neural. 
At  the  hinder  end  of  the  upper  surface  there  is  a  half-facet  for  another  bone,  one  of  the  series 
of  ossicles  mentioned  above.  The  neural  which  is  regarded  as  the  third  has  on  its  anterior 
end  a  half-facet  which  completes  the  one  on  the  supposed  second  neural.  Behind  this  facet 
is  a  sulcus,  believed  to  be  the  one  which  divides  the  first  from  the  second  vertebral  scutes. 
The  fourth  neural  has  no  tubercle  of  its  own,  but  its  hinder  end  supported  a  small  part  of 
the  tubercle  which  belongs  to  the  fifth  neural.  This  tubercle  has  a  length  of  20  mm.  Behind 
it  is  the  sulcus  which  passes  between  the  third  and  the  fourth  vertebral  scutes.  The  tubercle 
is  wholly  co-ossified  with  the  bones  on  which  it  rests,  but  there  are  traces  of  the  sutures.  The 
sixth  neural  is  sharp  along  the  midline,  while  its  sides  slope  steeply,  like  a  high-pitcht  roof. 
The  seventh  neural  is  short  and  closely  joined  to  the  eighth.  A  long  and  strongly  comprest 
tubercle  occupies  nearly  the  whole  length  of  both  these  neurals  and  appears  to  be  co-ossified 
with  both,  only  traces  of  the  sutures  remaining. 

The  suprapygals  are  co-ossified.  The  first  is  sharply  rooft,  while  the  next  one  has  a  rather 
high  and  comprest  tubercle.     The  anterior  suprapygal  appears  to  have  been  expanded  on 

each  side,  but  the  expansions  are  broken  away.  The  sulcus 
between  the  fourth  and  the  fifth  vertebral  scutes  doubtless 
crost  behind  the  tubercle  on  the  second  suprapygal.  The 
pygal  is  represented  in  plate  30,  fig.  I.  Its  height  is  14  mm.; 
its  width  from  side  to  side,  27  mm.  Its  upper,  or  anterior, 
border  appears  to  have  articulated  with  a  suprapygal  which 
is  now  missing.  The  upper  surface  of  the  pygal  is  longitudi- 
nally grooved,  while  the  inferior  has  a  more  extensive  longi- 
tudinal channel.  This  pygal  is  quite  different  from  that 
of  the  type  of  T.  stenopora.  The  dimensions  of  the  neurals 
and  suprapygals  are  shown  in  the  accompanying  table. 
It  is  evident  that  there  were  1 1  pairs  of  peripherals,  as 
in  most  turtles.  The  two  anterior  are  narrow  and  thin.  These  are  followed  by  4  others  which 
are  thicker  and  broader,  and  these  again  by  others  which  are  thin.  The  table  gives  the 
dimensions  of  the  peripherals  present.  The  width  is  taken  at  the  front  end. 

The  anterior  end  of  the  first  peripheral  is  obhque  for  articulation  with  the  nuchal.  The 
third  and  the  succeeding  peripherals  to  the  ninth  inclusive  have  each  a  pit  for  a  corresponding 
rib-end.  The  tenth  has  no  pit.  The  eleventh  is  not  present.  Since  the  hinder  end  of  the 
tenth  peripheral  is  19  mm.  wide  and  the  articular  end  of  the  pygal  only  12  mm.  wide,  it  follows 
that  the  eleventh  was  considerably  wider  at  one  end  than  the  other.  All  the  peripherals  are 
crost  by  shallow  sulci. 

Dr.  Wieland  has  represented  (Amer.  Jour.  Sci.,  xx,  1905,  p.  335,  fig  6;  here  reproduced 
as  fig.  229)  the  rib-end  of  the  eighth  costal  as  entering  a  pit  in  the  anterior  end  of  the  eleventh 

peripheral.  The  end  of  the  rib  was  not  present  and  it  is 
stated  that  the  rib-pits  are  all  small.  In  the  specimen 
figured  by  Dr.  Case  (Univ.  Geol.  Surv.  Kans.,  iv,  1898) 
the  eighth  costal  comes  down  to  a  thin  edge  and  there 
appears  to  have  been  no  rib-end.  Moreover,  Case  states 
that  the  eleventh  peripheral  has  no  groove  nor  pit  for  a 
rib.  At  my  request  Dr.  C.  E.  McClung,  of  the  University 
of  Kansas,  examined  this  specimen.  He  finds  the  pygal 
and  the  eleventh  peripheral  in  their  natural  positions  and 
the  eighth  costal  with  a  sharp  border  and  no  trace  of  a 
rib.  Case  is  probably  in  error  in  representing  the  rib  of 
the  seventh  costal  plate  as  going  to  the  tenth  peripheral. 
The  plastron  appears  to  have  resembled  quite  as  much  that  of  the  Cheloniidae  as  it  did  that 
of  Chelydra.    As  in  the  former  family,  that  part  of  the  plastron  which  lay  between  the  fore  and 


Element. 

length. 

Width. 

1 

27 

25 

i8 

23 

18 

22 

28 

M 

22 

20 

7 

'3 

18 

8 

10 

>5 

1st  suprapygal... 

24 

zd  suprapygal... 

•1        31 

13 

Peripherals. 

Length. 

Width 
upper  face. 

Thickness. 

, 

»S 

II 

2 

16 

II 

3 

30 

8 

12 

4 

33 

15 

'5 

s 

36 

12.5 

•5 

6 

38 

•5 

10 

7 

36 

15 

8 

8 

3* 

16 

5 

9 

33 

'5 

S-5 

10 

3» 

16 

7-5 

i66 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


hind  legs  was  much  broader  than  it  is  in  the  case  of  Chclydra;  and,  as  in  the  sea-turtles,  there 
was  a  fontanel  between  the  outer  end  of  the  hyoplastron  and  hypoplastron.  There  was  also 
an  extensive  umbilical  fontanel.  The  bones  of  the  right  and  left  sides  were  joined  along  the 
midline  more  like  those  of  Chelydra  than  like  those  of  the  Cheloniidae.  The  epiplastron  and 
entoplastron  are  figured  by  Wieland  (Amer.  Jour.  Sci.,  xx,  p.  336,  figs.  7,  8).  The  former  are 
slender,  the  latter  broad  and  lance-shaped.  The  xiphiplastron,  as  represented  by  that  of 
T.  stenopora  (Case,  op.  cit.,  plate  Ixxx.,  fig.  5),  is  slender  and  apposes  digitations  to  its  fellow. 
Cervical  vertebrae  have  been  figured  by  Dr.  Case  (op.  cit.,  plate  Ixxxiii,  figs.  2-4).  These 
were  more  or  less  injured,  being  comprest  laterally.  A  more  complete  series  is  in  the  Marsh 
collection  at  Yale,  and  these  have  been  described  by  Dr.  Wieland  (Amer.  Jour.  Sci.,  xiv,  1902, 
p.  102).  According  to  this  author,  the  anterior  5  have  their  articular  ends  fashioned  as  in 
Chelydra  and  the  great  majority  of  turtles;  that  is,  the  first  is  composed  of  4  bones;  the 
centra  of  the  second  and  third  are  convex  in  front  and  concave  behind;  that  of  the  fourth  is 
convex  at  both  ends,  as  in  turtles  generally.  The  next  four  centra  are  concave  at  the  anterior 
ends,  convex  at  the  posterior.  Toxochelys  differs  from  modern  Cheloniidae  in  not  having  the 
double  concavities  developt  on  the  anterior  end  of  the  last  cervical.  The  specimen  furnishing 
these  cervicals  was  not  accompanied  by  the  carapace,  so  that  we  can  not  estimate  the  length  of 


^  / 


x> 


Fig.  200. — Toxochelys  latiremis.     Front  limb.      X  .28.     Specimen  in  Yale  Univ.  coll. 

fl,  head  of  humerus;  fc,  radial  process;  c,  ulnar  process;  cen,  centrale;  e,  ectepicondylar  groove;  £,  entocondyle; 
hunty  humerus;  intj  intermedium;  pj  pisiforme;  rad^  radius;  «/,  ulna;  u/n,  ulnare;  I,  II,  etc.,  metacar- 
pals;   I,  2,  3,  etc.,  distal  carpal  bones.    Figure  by  Wieland. 

the  neck  relatively  to  the  shell.  The  estimated  length  of  the  neck  is  226  mm.  The  skull  was 
1 14  mm.  to  the  occipital  condyle. 

Regarding  the  caudal  vertebrae  little  that  is  certain  is  known.  It  is  not  at  all  improbable 
that  the  vertebrae  which  were  described  by  Cope  under  the  name  Cynocercus  incisus  belong  to 
Toxochelys.  Two  caudals  are  in  a  small  collection  of  bones  received  from  the  University  of 
Chicago,  with  the  catalog  number  230  and  belonging  to  Toxochelys  latiremis.  The  centrum 
of  one  is  18  mm.  long.  These  vertebrae  probably  belonged  toward  the  end  of  the  tail.  They 
are  procoelous  and  possess  short  lateral  processes.  In  general  these  vertebrae  resemble  those 
of  Cynocercus,  but  the  cup  is  deeper  and  without  sign  of  the  perpendicular  incision  seen  in 
Cynocercus,  and  the  ball  is  more  prominent. 

The  coraco-scapular  arch  is  more  like  that  of  the  sea-turtles  than  like  that  of  the  snappers. 
The  coracoid  is  long,  narrow,  and  spatulate.  A  considerable  neck  is  interposed  between  the 
glenoid  fossa  and  the  base  of  the  proscapular  process. 

The  fore  limb  is  best  known  from  a  specimen  in  the  collection  at  Yale  (fig.  200),  which 
has  been  described  by  Dr.  Wieland  (Amer.  Jour.  Sci.,  xiv,  1902,  p.  95,  fig.  i).  The  humerus 
has  also  been  figured  by  Dr.  Case.  Dr.  Leidy  also  has  figured  the  proximal  end  of  the  humerus 
of  what  is  no  doubt  a  member  of  this  genus  (Cont.  Ext.  Vert.  Fauna  West.  Terrs.,  1873,  plate 
xxxvi,  fig.  17).  For  a  figure  of  the  humerus  of  T.  latiremis  'see  fig.  200,  shown  above.  This 
specimen  was  accompanied  by  the  lower  jaw,  and  its  identification  thus  made  certain. 

The  humerus  of  Toxochelys  is  regarded  by  Dr.  Wieland  as  representing  the  form  which 
he  has  called  "thalassoid, "  especially  because  he  believes  that  the  radial  process  has  descended 
lower  on  the  shaft  than  it  is  in  Chelydra  and  that  the  ulnar  and  radial  processes  have  moved 


TOXOCHELYID^.. 


167 


nearer  their  respective  borders  of  the  huinerus.  To  the  present  writer  the  principal  changes 
which  have  affected  the  thalassic  and  parathalassic  humeri,  as  represented  by  Caretta  and 
Dermochelys,  are  to  be  found  in  the  straightening  of  the  shaft;  the  change  of  the  head  from  a 
position  looking  upward,  in  the  natural  position  of  the  bone,  to  one  looking  toward  the  median 
plane  of  the  animal;  the  descent  of  the  radial  process,  on  the  shaft;  the  transference  of  this 
process,  or  of  a  component  of  it,  toward  the  radial  border;  and  the  removal  of  the  condyles 
for  the  radius  and  ulna  and  of  the  ectepicondylar  foramen  or  groove  toward  the  ulnar  border  of 
the  bone.  Of  all  these  changes  none  seems  to  have  taken  place  in  Toxochelys,  except  a  slight 
descent  of  the  radial  process.  In  every  other  respect  the  bone  retains  the  characteristics  of 
ChelyJra. 

In  many  other  features  the  fore  limb  of  Toxochelys  has  made  approaches  to  the  flipper  of 
the  marine  turtles,  as  Dr.  Wieland  has  shown.  The  ulna,  as  compared  with  that  of  Chelydra, 
has  become  shorter  relatively  to  the  humerus  while  the  radius  has 
become  longer,  as  it  has  also  to  a  greater  degree  in  Caretta.  The  ulna 
has  become  shorter  than  the  radius,  and  the  third  and  fourth  fingers 
have  become  greatly  elongated;  but  in  these  respects  it  is  far  behind 
Caretta.  The  first  and  second  fingers  retain  about  the  same  ratio  to 
the  humerus  that  they  have  in  Chelydra.  Taken  altogether,  the  limb 
may  be  regarded  as  standing  between  that  of  Chelydra  and  the  sea- 
turtles  but  nearer  to  that  of  Chelydra.  From  the  fact  that  the  head  of 
the  humerus  had  the  position  that  it  has  in  the  freshwater  turtles  and 
that  the  phalanges  possest  well-developt  condyles  we  may  be  quite  cer- 
tain that  the  species  of  Toxochelys  had  no  difficulty  in  getting  about 
on  the  land. 

The  first  and  second  fingers  of  Toxochelys  were  composed  of 
phalanges  which  were  much  stouter  than  those  of  the  other  fingers. 
The  terminal  phalanges  were  encased  in  horn  and  formed  strong 
curved  claws.  The  other  fingers  did  not  probably  extend  beyond  the 
border  of  the  skin.  Dr.  Case  (op.  cit.,  plate  Ixxxii,  figs,  i,  2)  repre- 
sents the  first  finger  as  having  3  phalanges.  This  figure  is  evidently 
that  of  the  second  finger. 

The  following  measurements  are  taken  from  Dr.  Wieland's  des- 
cription of  the  fore  limb  in  Yale  University  Museum  (fig.  200) :    Length 
of  humerus,  135  mm.;    radius,  75  mm.;    ulna,  66  mm.;   total  length 
of  the  first  finger,  65  mm.;  of  second  finger,  95  mm.;  of  third  finger, 
estimated,  130  mm.;   of  fourth  finger,  estimated,  135  mm.;   of  fifth  finger,  estimated,  90  mm. 
The  pelvis  is  somewhat  more  like  that  of  Caretta  than  like  that  of  Chelydra.     Dr.  Case 
has  given  figures  of  the  ilium  (op.  cit.,  plate  Ixxxi.,  fig.  8)  and  of  the  ischium  (op.  cit.,  pi.  Ixxxii, 
fig.  6).     The  antero-lateral  processes  of  the  pubis  are  broader  than  they  are  in  Chelydra. 
The  femur  is  not  an  uncommon  bone  in  collections  of  Toxochelys  materials.     Figures  of 
the  bone  are  presented  hy  Case  (op.  cit.,  plate  Ixxxi)  and  Leidy  (op.  cit.,  plate  xxvi,  fig.  18). 
Unfortunately  the  bone  is  usually  crusht,  so  that  its  exact  form  is  questionable.    It  is  certain, 
however,  that  the  greater  and  the  lesser  trochanters  were  separated  by  a  deep  fossa,  as  Case 
has  described  the  bone.     This  fossa  was  probably  like  that  found  in  Chelydra.     In  Caretta 
and  again  in  Testudo  this  fossa  is  nearly  obsolete.    Case  believed  that  the  femur  was  a  weaker 
bone  than  the  humerus.     This  view  is  probably  correct,  and  is  corroborated  by  the  relative 
izes  of  the  humerus  and  femur  figured  by  Leidy.    It  is  not  certain,  however,  that  these  bones 
belonged  to  the  same  individual.    In  Chelydra  the  femur  is  the  longer  bone. 

The  tibia  and  fibula  are  not  well  known.  There  is  presented  in  fig.  201  a  portion  of  the 
hinder  limb  in  the  possession  of  the  author  and  believed  to  belong  to  Toxochelys.  The  tibia 
and  fibula  are  elongated  and  slender,  more  like  those  of  Chelydra  than  like  those  of  Caretta. 
Four  tarsals  are  present.  The  metatarsal  is  probably  that  of  the  first  toe.  Case  (op.  cit.,  p.  378) 
describes  the  hind  foot  of  an  incomplete  specimen,  but  the  error  is  made  of  assigning  four 
phalanges  to  the  first  digit.  The  digit  may  have  been  the  second,  including  the  metatarsal. 
The  terminal  claw  was  strong  and  much  curved.  The  phalanges  of  the  remaining  digits  were 
longer  and  slenderer,  and  the  terminal  one  did  not  support  a  claw. 


Fig.  201.- 

sp.  indet.  Tibia,  fib- 
ula, and  some  foot 
bones,      xi. 


i68 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


Key  to  Species  of  Toxochelvs. 
A.  Species  based  on  skull. 

a.  Symphysis  of  lower  jaw  short,  about  one-fifth  of  length  of  lower  crushing-surface  of  jaw. 
b.  Snout  rather  pointed. 

c.  Jaws  slender  and  weak;    symphysis  thin,  sloping  on  upper  surface latiremis 

cc.  Jaw  rather  heavy;   the  upper  surface  of  the  symphysis  horizontal serrtfer 

hb.  Snout  broad  and  rounded hrachyrhina 

aa.  Symphysis  long,  at  least  one-third  the  length  of  the  crushing-surface. 

d.  Nasal  opening  narrow;   upper  surface  of  the  symphysis  sloping stenopora 

dd.  Nasal  opening  normal;    symphysis  flat  above. 

e.  Skull  as  broad  as  long elkader 

ee.  Skull  longer  than  broad procax 

A  A.  Species  based  on   shell  only bauri 


Figs.  202-205. — Toxochelys  latiremis.     Skulls  and  lower  jaw.      Xj. 

202.  Upper  view  of  front  of  skull.    No.  1496  A.M.N.  H. 

Z03.  Upper  view  of  skull.    No.  1497A.  M.  N.  H.    at,  atlas;  ^iv,  axis;   s;,  squamosal. 

204.  Lower  view  of  same  skull  as  preceding,    at,  atlas;   ax,  axis;  qu,  quadrate;   sq,  squamosal. 

205.  Dentary  portion  of  lower  jaw,  with  section  along  the  symphysis.    No.  1497  A,  M.  N.  H. 

Toxochelys  latiremis  Cope. 

Figs.  200,  202-206. 

Toxochelys  latiremis.  Cope,  Proc.  Acad.  Nat.  Sci.  Phila.  1873,  p.  10;  Vert.  Cret.  Form.  West,  1875, 
pp.  98,  260,  pi.  viii,  figs.  I,  2;  Proc.  Amer.  Fhilos.  Soc,  xvii,  1877,  p.  176. — Hay,  Pubs.  Field 
Columb.  Mus.,  Zool.,  I,  1896,  p.  loi,  pis.  xiv,  xv;  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  442; 
Bull.  Amer.  Mus.  Nat.  Hist.,  xxi,  1905,  p.  177. — Case,  Univ.  Kansas  Geol.  Surv.,  iv,  1898,  p.  371, 
plate  Ixxix;  plate  Ixxx,  figs,  i,  2;  .'plate  Ixxxi,  figs.  1-8,  10-13;  -'p'ste  Ixxxii,  figs,  i,  2;  plate  Ixxxiii, 
figs.  2-4. — ^Wagner,  Kansas  Univ.  Quarterly,  vii,  A,  1898,  p.  201,  fig.  I.— Wieland,  Amer.  Jour. 
Sci.  (4),  xiv,  1902,  p.  95,  figs.  1,2.^ 

Cynocercus  incisus,  Leidy,  Cont.  Ext.  Vert.  Fauna  West.  Terrs.,  1873,  P-  ^79,  plate  xxxvi,  figs.  17-21. 

The  type  of  the  present  species  consists  of  a  portion  of  the  lower  jaw  and  a  coracoid,  of 
the  Cope  collection  of  reptiles  and  fishes,  and  is  now  in  the  American  Museum  of  Natural 
History,  New  York,  having  the  number  2362.     The  specimen  was  collected  by  Professor 


TOXOCHELYID^. 


169 


B.  F.  Mudge,  in  the  Niobrara  deposits  of  Kansas,  near  the  forks  of  the  Smoky  Hill  River. 
The  animal  was  a  large  one,  since  the  mandible,  from  the  symphysis  to  the  angle  of  the  jaw, 
measures  157  mm.  In  1877,  as  cited  in  the  synonymy,  Professor  Cope  came  into  possession 
of  2  nearly  complete  skulls,  which  he  identified  as  belonging  to  T.  latiremis,  and  these  he 
described.  These  skulls  are  now  in  the  American  Museum  and  bear  respectively  the  numbers 
1496  (fig.  202)  and  1497  (figs.  203,  204).  The  latter  (and  probably  both  specimens)  was 
collected  somewhere  along  the  Smoky  Hill  River.  A  comparison  of  the  lower  jaws  of  these 
skulls  with  that  of  the  type  makes  it  certain  that  the  former  were  correctly  referred. 

The  first  publisht  figure  of  the  skull  of  this  species  was  made  by  Hay,  as  cited.  This 
skull  lackt  the  lower  jaw;  but  a  comparison  with  the  skulls  described  by  Cope  reveals  no 
differences.    Other  skulls  have  been  figured  by  Case  and  Williston,  as  cited. 

This  appears  to  have  been  the  commonest  turtle  in  the  Niobrara  beds  of  Kansas,  yet  many 
parts  of  its  skeleton  remain  unknown.  The  size  attained  was  considerable.  If  the  length  of 
the  coracoid  bore  the  same  relation  to  the  length  of  the  carapace  that  subsists  between  these 
bones  in  Chelydra  or  Caretta,  the  carapace  must  have  been  about  a  meter  in  length.  It  may  be 
remarkt  here  that  the  coracoid  of  Cope's  type  was  225  mm.  long,  that  author's  statement 
that  it  was  250  mm.  being  incorrect.  The  ramus  of  the  mandible  has  a  length  of  157  mm.,  so 
that  the  skull,  from  the  tip  of  the  snout  to  the  occipital  condyle,  was  close  to  160  mm. 

The  skull  of  this  species  is  broad  posteriorly. 
In  front  of  the  quadrates  the  width  is  gradually 
reduced,  so  that  the  head  is  wedge-shaped  and 
the  snout  pointed.  Altho  all  the  skulls  yet  found 
are  considerably  flattened  by  pressure,  it  is  quite 
certain  that  the  head  was  rather  deprest,  more 
like  that  of  Chelydra  than  like  that  of  any  of  the 
living  Cheloniidae.  The  supraoccipital  is  long. 
The  temporal  region  is  rooft  over  about  as  in 
Caretta,  and  the  squamosal  appears  to  have  come 
into  narrow  contact  with  the  parietal.  The  orbits 
lookt  upward  and  outward,  resembling  more 
those  of  Chelydra  than  those  of  the  Cheloniidae. 
The  opening  of  the  anterior  nares  is  large,  con- 
trasting strongly  with  that  of  T.  stenopora.  The 
tympanic  cavity  did  not  extend  into  the  squa- 
mosal, but  had  the  stage  of  development  seen  in 
the  loggerhead.  The  cutting-edge  of  the  maxilla 
is  moderately  high  anteriorly,  but  becomes  very 
low  at  the  hinder  end.  As  seen  in  profile,  it  is  convex.  There  is  a  rough  ridge  on  the  palatine 
near  its  articulation  with  the  maxilla.  The  alveolar,  or  masticatory,  surface  of  the  upper  jaw  is 
somewhat  concave  from  side  to  side.  Including  the  ridge  on  the  palatine,  this  surface  is  not 
so  wide  as  is  the  fossa  containing  the  choanae.  There  are  large  posterior  palatine  foramina. 
The  narrowest  portion  of  the  palate,  across  the  pterygoids,  is  rather  wide  compared  with  the 
other  species,  and  is  flat.  More  posteriorly  each  pterygoid  bears  a  groove  which  is  directed 
outward  and  backward  toward  the  hinder  border  of  the  quadrate. 

The  lower  jaw  is  relatively  weak.  The  alveolar  surface  is  narrower  than  in  the  other 
species  in  which  it  has  been  observed.  Fig.  205  represents  the  lower  jaw  belonging  to 
specimen  shown  in  figures  203  and  204.  The  outer  edge  is  sharp  and  rises  somewhat  above 
the  inner  edge.  The  latter  rounds  off  into  the  inner  face  of  the  jaw,  which  face  is  in  no 
way  hidden  by  the  surface  referred  to.  At  the  symphysis  the  alveolar  surface  extends  back- 
ward little  more  than  one-half  as  far  as  does  the  lower  face  of  the  bone.  The  tip  of  the  jaw  is 
slightly  beakt. 

Notwithstanding  the  fact  that  a  considerable  number  of  skulls  of  this  species  have  come 
to  light,  portions  of  the  carapace  or  plastron  are  rare.  Wieland  (as  cited)  mentions  portions 
of  the  carapace  and  plastron  in  Yale  University,  but  he  does  not  describe  them. 

The  cervical  vertebra  and  some  caudals  have  already  been  described  in  the  discussion 
of  the  genus.    No  other  vertebrae  are  known. 


Fig.   206. — Toxochelys  lattremis.     Scapula  and 
coracoid.    Xj.  Redravpn  from  figures  by  Case. 


170 


FOSSIL    TURTLES    OF    NORTH    AMKRICA. 


For  description  of  the  shoulder-girdle  (fig.  206,  from  Case)  and  remarks  thereon,  see  page 
166.     The  structure  of  the  anterior  limb  has  also  been  described  and  illustrated. 

No  pelvis  definitely  known  to  belong  to  this  species  has  been  described.  References  to 
femora  supposed  to  belong  to  this  species  have  already  been  given,  but  these  may  have  belonged 
to  other  species,  as  T .  procax  or  T .  brachyrhina.  Case  (op.  cit.,  p.  378)  describes  a  hind  foot 
which  he  refers  to  T.  latiremts.     This  has  already  been  mentioned  on  page  167. 

Wagner  has  described  and  figured  a  portion  of  a  skull  of  a  turtle  from  the  Pierre  shales 
of  Kansas,  which  he  identifies  as  T.  latiremts.  The  present  writer  has  not  seen  this  skull. 
The  lower  jaw  figured  by  Wagner  certainly  does  not  belong  to  T .  latiremts. 

Toxochelys  serrifer  Cope. 

Figs.  207-213. 

Toxochelys  serrifer,  Cope,  Vert.  Cret.  Form.  West,  1875,  p.  299. — Hay,  Bibliog.  and  Cat.  Foss.  Vert. 
N.  A.,  1902,  p.  442;    Bull.  Amer.  Mus.  Nat.  Hist,  xxi,  1905,  p.  178,  figs.  1-7. 

The  type  of  this  species  is  No.  1835  of  the  Cope  collection  of  reptiles  and  fishes  in  the 
American  Museum  of  Natural  History,  New  York.  It  consists  of  the  greater  portion  of  both 
maxillae,  the  left  dentary,  the  greater  portion  of  the  pterygoids,  the  right  quadrate,  the  frontals 


212 


Figs.  207-212. — Toxochelys  serrifer.     Portions  of  skull  of  type.      Xi. 


207.  Left  dentary.    Shows  cutting-edge  and  grinding- 

surface. 

208.  View  of  inner  face  of  dentary. 

209.  Symphysis  of  lower  jaw. 


210.  Cutting-edge  and  grinding-surface  of  upper  jaw. 

mx,  maxilla;   pat,  portion  of  palatine. 

211.  Base  of  skull,    fcoc,  basioccipital;   />f,  pterygoid. 

212.  Upper  aspect  of  skull,    /r,  frontalsj   pa,  parie- 

tal;  prjj  prefrontal. 


and  prefrontals,  and  two  peripherals.  They  were  collected  somewhere  in  the  Niobrara  deposits 
of  Kansas  by  Professor  Merrill,  in  1865. 

The  dentary  (figs.  207-209)  had  not  yet  become  co-ossified  with  its  fellow.  Its  length  is, 
as  Cope  states,  48  mm.;  its  width  above,  9  mm.;  the  depth  of  the  inner  face,  7  mm.  Longi- 
tudinally the  alveolar  surface  is  more  strongly  concave  than  in  T.  latiremts.  Near  the  sym- 
physis the  surface  is  considerably  concave  transversely,  but  posteriorly  it  is  nearly  flat.  The 
inner  border  of  this  surface  is  nearly  on  the  same  level  as  the  outer.  At  the  symphysis  (fig.  209) 
the  alveolar  surface  extends  nearly  as  far  backward  as  does  the  lower  face  of  the  bone.  The 
inner  face  of  the  dentary  is  occupied  by  a  broad  groove.  The  length  of  the  alveolar  surface  of 
the  symphysis  is  9  mm. 

Slightly  more  than  the  posterior  half  of  each  maxilla  (fig.  210)  is  present.  The  alveolar 
surface  is  flat,  and  the  cutting-edge  retains  its  height  to  its  hinder  end.  In  T.  latiremis  the 
height  becomes  reduced  posteriorly.  The  pterygoids  (fig.  211,  pt)  present  no  peculiarity. 
Where  narrowest  the  portion  of  the  palate  formed  by  the  pterygoids  is  15  mm.  wide.  The 
quadrate  does  not  differ  from  that  of  T.  latiremis,  except  that  the  articular  surface  for  the 


rOXOCHEl.YID^. 


171 


Fig.  21^ — Tosochehs  ser- 
rijer.  One  peripheral 
and  part  of  another. 
XI. 


lower  jaw  is  much  smaller.     This  surface  is  triangular,  the  inner  lobe  seen  in  T.  latiremis 
being  greatly  reduced  in  T .  serrifer. 

The  interorbital  space  (fig.  212)  had  a  width  of  16  mm.  where  narrowest.  The  groove  on 
the  under  surface  of  the  frontals  for  the  olfactory  nerve  is  relatively  narrower  than  in  T. 
latiremis,  in  which  the  groove  is  nearly  one-third  as  wide  as  the  interorbital  space;   whereas, 

in  T.  serrifer  it  is  only  about  one-sixth  the  width  of  that  space.  The 
anterior  borders  of  the  prefrontals  are  broken  away,  so  that  the 
width  of  the  anterior  narial  passage  can  not  be  determined.  It  is 
certain,  however,  that  the  nasal  cavity  itself  had  the  lateral  extent 
that  it  had  in  T.  latiremis. 

An  estimate  shows  that  the  length  of  the  skull  from  the  snout  to 
the  occipital  condyle  was  about  80  mm. 

Two  adjacent  peripheral  bones  are  present,  probably  the  left 
eighth  (fig.  213)  and  the  ninth.  The  eighth  is  40  mm.  long  and  32 
mm.  wide,  the  ninth  43  mm.  long  and  32  mm.  wide.  Each  is  notcht 
just  behind  the  widest  portion  and  here  the  width  of  the  eighth  is  25 
mm.,  of  the  ninth  27  mm.  The  thickness  of  the  inner  face  is  nearly 
7  mm.,  and  at  the  hinder  end  of  this  face  is  a  pit  for  a  rib. 

The  specimens  which  were  referred  to  this  species  by  Case  (Univ. 
Geol.  Surv.  Kan.,  iv,  p.  379)  are  described  as  T.  stenopora.  From 
the  latter  species  T .  serrifer  differs  in  having  a  dentary  with  an 
alveolar  surface  much  wider  in  proportion  to  its  depth,  and  not  beakt 
at  the  tip. 

It  is  evident  that  the  skull  (and  probably  the  whole  skeleton)  of  T.  serrifer  was  much  larger 
than  that  of  T.  stenopora.  This  makes  it  all  the  more  remarkable  that  the  dentary  of  the 
former  is  relatively  so  short  and  that  the  depth  of  T.  stenopora  is  so  great.  It  seems  not  im- 
probable that  the  carapace  and  part  of  the  plastron  described  by  Wieland  as  T.  baurt  will 
prove  to  belong  to  the  present  species. 

Toxochelys  brachyrhina  Case. 

Plate  31,  fig.  1. 

Toxochelys  brachyrhinus ,  Case,  Univ.  Geol.  Surv.  Kansas,  iv,  1898,  p.  378,  pi.  Ixxxiv,  figs,  i,  2.— Hay, 
Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  442;   Bull.  Amer.  Mas.  Nat.  Hist.,  xxi,  1905,  p.  177. 

The  type  of  this  species  is  a  skull,  the  property  of  Kansas  University,  and  bearing  the 
number  1 21 2.  Dr.  Case's  description  of  it  is  exceedingly  brief.  The  character  which  he  gives 
as  distinguishing  it  from  T.  latiremis  is  the  much  blunter  snout.  Case's  fig.  I  of  his  plate  is 
three-fourths  of  the  natural  size;  and,  while  the  form  of  the  skull  is  shown,  the  details  are  not 
well  represented.  His  fig.  2  is  a  restoration  of  the  size  of  nature,  but  it  does  not  indicate  the 
sutures;  likewise  it  represents  the  anterior  half  of  the  skull  as  somewhat  too  broad. 

The  skull  of  this  species  appears  to  be  distinguisht  from  that  of  T.  latiremis  in  being 
narrower  posteriorly  in  relation  to  the  length  and  in  having  a  broader  snout.  Another  distin- 
guishing character  seems  to  be  found  in  the  narrower  posterior  region  of  the  palate.  In  the 
case  of  a  large  specimen  of  T.  latiremis,  130  mm.  from  the  snout  to  the  occipital  condyle,  the 
pterygoid  portion  of  the  palate,  where  narrowest, is  36  mm.  wide.  In  the  type  off.  brachyrhina, 
1 17  mm.  to  the  occipital  condyle,  the  palate  is  only  20  mm.  wide.  The  interorbital  space  also 
is  relatively  narrower  than  in  T.  latiremis.  In  the  specimen  of  the  latter  referred  to,  the  space 
between  the  orbits  is  24  mm.  wide,  in  T.  brachyrhina,  only  19  mm.— too  great  a  difference  to 
be  due  to  difference  of  size  alone. 

The  following  measurements  are  given  of  the  type  specimen: 

Millimeters. 

Length  from  the  snout  to  the  occipital  condyle n? 

Length  to  extremity  of  supraoccipital  bone I34 

Distance  between  the  outer  faces  of  quadrates 9° 

Distance  between  outsides  of  squamosals 94 

Width  at  hinder  borders  of  orbits °° 

Width  at  front  of  orbits 5° 


172 


FOSSIL    TURTLES    OK    NORTH    AMERICA. 


The  anterior  nares  do  not  appear  to  have  been  different  from  those  of  T.  latiremis.  As 
seen  in  the  type  and  the  figures  here  presented,  the  quadrates  have  been  squeezed  forward 
somewhat.  The  lower  jaw  is  present,  but  is  so  closely  prest  against  the  roof  of  the  mouth 
that  its  alveolar  surface  can  not  be  seen.  So  far  as  can  be  judged,  it  is  not  greatly  different 
from  that  of  T.  latiremis;  but  the  symphysis  is  evidently  shorter.  It  is  very  desirable  that 
this  surface  should  be  seen,  in  order  to  distinguish  this  species  clearly  from  T .  serrifer. 

In  explanation  of  the  figure,  it  should  be  said  that  the  inner  nares  are  hidden  by  some 
fragments  of  bone,  probably  of  the  hyoids. 

The  type  was  found  in  the  Niobrara  deposits  of  Gove  County,  Kansas. 


220 


Figs.  214-220. — Toxochelys  stenopora.     Portions  of  type. 


214.  Dentary  portion  of  lower  jaw.     Xi. 

215.  Left  dentary,  showing  inner  face.     Xi. 

216.  Section  along  symphysis  of  lower  jaw.     Xi. 

217.  Upper  aspect  of  skull.     Xi.    /r,  frontal ;  mx, 

maxilla  ;    pa,  parietal ;    pal,  palatine  ;    pmx, 
premazilla ;  prf,  prefrontal ;   pt,  pterygoid . 


218.  View  of  palatal  surface  of  skull.     Xi.' 

219.  Supraoccipital.     Xi. 

220.  Left  hyoplastron,  hypoplastron,  and  xiphiplastron 

of  type.     X^.    Redrawn  from  figure  by  Case. 


Toxochelys  stenopora  Hay. 

Figs.  214—220. 

Toxochelys  serrifer.  Case,  Univ.  Geol.  Surv.  Kansas,  iv,  1898,  p.  379,  plate  Ixxx,  figs.  3-9;  plate  Ixxxii, 
figs.  4,  5;  plate  Ixxxiii,  fig.  i. — Hay,  Amer.  Naturalist,  xxxil,  1898,  p.  935,  figs.  1-3;  Bibliog.  and 
Cat.  Foss.  Vert.  N.  A.,  1902,  p.  442,  in  part. — Williston,  Trans.  Kansas  Acad.  Sci.,  xvil,  1901, 
p.  198. 

Toxochelys  stenoporus,  Hay,  Bull.  Amer.  Mas.  Nat.  Hist.,  xxi,  1905,  p.  180,  figs.  8-12. 

The  present  writer  is  not  able  to  agree  with  Dr.  Case  in  his  identification  of  the  testudinate 
remains  belonging  to  the  University  of  Kansas  which  he  has  described  and  figured  as  Tox- 
ochelys serrifer.  The  type  of  Cope's  T.  serrifer  belongs  to  the  American  Museum  of  Natural 
History  and  was  not  accessible  to  Dr.  Case  when  he  was  studying  the  fossil  turtles  of  Kansas. 

Of  the  bones  figured  by  Case,  the  skull  (plate  Ixxxii,  figs.  4,  5),  the  marginals  (fig.  i, 
plate  Ixxxiii),  and  the  hyoplastron  (fig.  3,  plate  Ixxx),  are  markt  with  the  number  2060;  while 
the  elements  furnishing  fig.  4  of  the  last-named  plate,  and  the  neurals  and  suprapygal  of  fig.  i. 


1 

Dimension. 

Toxochelys 
serrifer. 

: 

Toxochelys  r 
stenopora,  \ 

33 
6-S 

7 

9 

11.5 

Length  from  tip  of  jaw  to  hinder  end 

48 
9 

7 

8 

10 

Width  of  grinding  surface 

Width   of  inner  face  at   middle  of 

length  

Whole  depth  of  jaw  at  middle 

Length  of  symphysis  on  upper  surface 

TOXOCHELYID^.  17-1 

plate  Ixxxiii,  belong  to  No.  1270.    There  appears  to  be  no  reason  for  doubting  that  these  bones 
all  belong  to  the  same  species. 

The  principal  differences  between  the  present  species  and  Cope's  T.  serrifer  must  be  sought 
in  the  form  of  the  lower  jaws  and  of  the  peripheral  bones.    Unfortunately  we  can  not  determine 

the  form  of  the  anterior  nares  of  T.  serrifer. 
The  lower  jaw  of  T.  serrifer  shows  no  indica- 
tions of  a  beak,  while  that  of  T.  stenopora 
(figs.  214-216)  is  plainly  beakt.  Case  recog- 
nized this  difference.  The  table  herewith 
presents  the  dimensions  of  the  two  jaws. 

It  is  seen  from  these  measurements  that, 
although  the  lower  jaw  of  T.  stenopora,  as 
represented  by  the  masticatory  surface,  is 
much  shorter  than  that  of  T.  serrifer,  the  jaw 
is  nevertheless  deeper,  the  inner  face  of  equal 
depth,  and  the  symphyseal  line  of  the  masticatory  surface  longer.  The  width  of  the  inner 
face  of  T.  stenopora  may  be  somewhat  greater  than  the  figures  indicate,  since  there  is  evi- 
dence of  some  downward  crushing.  The  symphyseal  line  above  slopes  downward  and  back- 
ward in  T.  stenopora;  in  T.  serrifer,  it  is  nearly  horizontal. 

The  peripherals  of  T.  serrifer  are  much  broader  and  flatter  in  proportion  to  their  length 
than  in  T.  stenopora.  Thus,  in  comparing  what  appear  to  be  the  eighth  peripherals,  we  find 
that  of  T.  serrifer  measuring  49  mm.  in  length  and  32  mm.  in  width,  while  that  of  T.  steno- 
pora is  23  mm.  long  and  10  mm.  wide. 

The  bones  bearing  the  number  2060  of  Kansas  University  museum  are  made  the  type 
of  the  present  species,  and  in  case  it  should  be  found  that  the  skull  and  the  other  bones  of 
2060  are  not  all  of  the  same  species,  the  former  is  to  be  regarded  as  the  type. 

As  will  be  seen  from  the  figures  (figs.  217,  218),  the  skull  has  been  damaged,  especially  the 
hinder  portion.  Nearly  the  whole  of  the  roof  of  the  temporal  region  is  missing.  The  quadrates 
and  the  supraoccipital  are  present,  but  detacht  from  the  rest  of  the  skull.  Dr.  Case's  figures 
represent  the  skull  as  larger  by  one-half  than  the  originals;  but  this  has  probably  been  due  to 
the  failure  of  the  engraver  to  reduce  the  original  drawings. 

The  skull  was  evidently  short  and  broad.  The  distance  between  the  hinder  ends  of  the 
maxillae  equaled  the  distance  from  the  snout  to  the  middle  of  the  basisphenoid;  whereas  in 
T.  latiremis  the  distance  between  the  extremities  of  the  maxillae  extends  only  to  the  narrowest 
portion  of  the  pterygoids.  The  length  of  the  skull  to  the  hinder  border  of  the  basisphenoid  is 
46  mm.;  to  the  occipital  condyle  was  probably  about  10  mm.  more;  while  the  length  to  the 
hinder  end  of  the  supraoccipital  bone  was  about  82  mm.  The  palate,  where  narrowest,  is 
10  mm.  wide;  the  interorbital  space,  13  mm.  The  alveolar  surface  of  the  upper  jaw,  including 
the  rough  ridge  on  the  palatine,  is  relatively  broader  than  in  T.  latiremis,  being  contained  in 
the  length  of  the  cutting-edge  3  times.  In  T.  latiremis  it  is  contained  4  times.  This  increase 
in  the  width  of  the  surface  appears  to  be  at  the  expense  of  the  fossa  for  the  choanae,  which  is 
but  little  wider  than  the  surface  referred  to;  whereas  in  T.  latiremis  the  fossa  is  much  wider. 
In  the  wideness  of  the  alveolar  surface  and  the  narrowness  of  the  fossa  the  present  species 
resembles  T.  procax. 

There  were  without  doubt  posterior  palatine  foramina,  as  in  the  other  species  of  the  genus. 
That  which  distinguishes  this  species  from  all  others  of  the  genus,  so  far  as  known,  is  the 
narrowness  of  the  anterior  nares.  This  slit-like  opening  is  evidently  natural,  or  due  only  very 
slightly  to  any  compression  during  fossilization.  The  skull  is  flattened  somewhat  by  pressure, 
from  which  condition  we  may  conclude  that  the  narial  opening  originally  had  possibly  a  more 
perpendicular  position  than  at  present. 

A  portion  of  one  parietal  bone  is  among  the  remains  of  the  skull.  It  presents  a  part  of 
the  roof  of  the  temporal  region.  The  supraoccipital  (fig.  219)  has  a  length  of  35  mm.  and  a 
maximum  height  of  16  mm.,  being  thus  relatively  long  and  high. 

This  skull  is  accompanied  by  the  pygal  and  nearly  all  of  the  peripherals  of  one  side.  Some 
of  these  have  been  figured  by  Dr.  Case  (op.  cit.,  plate  Ixxxiii,  fig.  i).  The  pygal  has  a  sharp 
posterior  border  and  a  rounded  anterior  border.    From  the  latter  there  springs  a  process  which 


174 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


has  joined  the  hindermost  supiapygal.  Above  and  below,  the  pygal  is  broadly  grooved  from 
front  to  back.  The  most  anterior  peripheral  is  thin  and  narrow.  The  second  is  only  slightly 
wider.  The  third  has  its  inner  face  more  developt  and  possesses  a  pit  which  received  the 
extremity  of  the  rib  of  the  first  costal  plate.  The  inner,  or  costal,  face  of  the  succeeding  periph- 
erals increases  in  breadth,  until  a  section  of  the  bone  is  a  nearly  equilateral  triangle;  then 
the  face  is  reduced,  so  that  at  about  the  eighth  the  bone  has  grown  quite  thin  and  flat  and 
relatively  broad.  Each  peripheral,  except  the  first  and  the  second,  has  a  pit  for  the  reception 
of  a  rib-end,  until  we  come  to  the  tenth. 

Ordinarily  in  turtles  the  eighth  costal  plate  sends  its  rib  to  the  tenth  peripheral,  but  in 
Toxochelys  the  eighth  costal  plate  is  short  and  its  rib  does  not  extend  beyond  the  border  of  the 
plate.  As  in  Chelydra  and  most  other  turtles,  there  is  no  rib-end  reaching  the  eleventh  periph- 
eral. In  the  Cheloniidae  the  rib  of  the  eighth  costal  plate  is  turned  backward  to  this  periph- 
eral, one  of  the  more  anterior  peripherals  not  receiving  a  rib.  However,  Wieland  represents 
the  rib  of  the  eighth  costal  plate  as  entering  a  pit  in  the  eleventh  peripheral.  See  fig.  235  of 
the  present  work. 

No.  1270  of  the  Kansas  University  museum  furnishes  a  number  of  costal  plates,  a  few 
neurals  and  the  anterior  suprapygal  bone.  These  are  represented  in  Case's  figure  already 
referred  to.  According  to  the  present  writer's  views,  another  peripheral  ought  to  be  inserted 
between  the  last  one  of  that  figure  and  the  pygal;  and  there  was  almost  certainly  at  least  one 
suprapygal  behind  the  one  there  represented.  The  neural  which  Dr.  Case  has  called  the  ninth 
is  certainly  the  eighth,  since  it  has  articulated  with  it  the  eighth  costal.  Resting  partly  on  this 
neural  and  the  first  suprapygal  is  a  comprest  tubercle  at  the  base  of  which  is  a  distinct  suture. 
The  neural  seen  in  front  of  the  one  just  referred  to  is  probably  in  its  correct  position;  but  the 
next  one  in  front  is  certainly  wrongly  placed,  being  probably  the  fifth.  The  facet  on  the  anterior 
end  of  the  upper  surface  of  the  sixth  has  undoubtedly  supported  a  tubercle  similar  to  the  one 
resting  on  the  eighth  neural. 

The  midline  of  the  carapace  of  T.  stenopora  was  traverst  by  a  sharp  and  tuberculated 
keel,  such  as  has  been  described  as  occurring  in  the  specifically  undetermined  species  (p.  164). 
As  in  that  form,  the  more  anterior  tubercles  were  connected  with  their  underlying  bones  by 
open  sutures.   The  elevation  of  the  shell  was  probably  about  the  same  that  we  find  in  Chelydra. 

In  the  figure  presented  by  Dr.  Case,  the  costal  plates  are  probably  correctly  placed  with 
reference  to  one  another.  As  will  be  seen,  there  were  large  fontanels  between  the  distal  ends 
of  the  ribs. 

The  plastron  is  represented  by  fig.  220,  reproduced  from  Dr.  Case's  work  so  often  quoted. 
Nothing  is  known  regarding  the  entoplastron  and  epiplastron.  There  was  a  large  umbilical 
fontanel,  while  there  was,  on  each  side,  another  fontanel  bounded  by  the  peripherals  outwardly 
and  by  the  hyoplastron  and  hypoplastron  in  front  and  behind.  The  lateral  digitations  of  the 
plastral  bones  did  not  enter  into  pits  in  the  peripherals.  The  median  digitations  probably 
approacht  closely  those  of  the  opposite  side.  A  prominent  longitudinal  ridge  on  each  side 
crost  the  hyoplastron  and  hypoplastron. 

Toxochelys  elkader  sp.  nov. 

Figs.  Z2I-223. 

Of  the  type  of  this  species.  No.  6137  of  the  American  Museum  of  Natural  History,  there 
were  secured  the  skull  nearly  complete;  large  portions,  perhaps  the  whole,  of  the  plastron; 
the  shoulder-girdles;  portions  of  the  pelvis;  and  apparently  one  or  two  peripherals.  Excepting 
the  skull,  the  parts  have  not  yet  been  prepared  for  study.  The  specimen  was  found  in  the 
Niobrara  beds,  near  Elkader,  Logan  County,  Kansas,  by  Mr.  H.  T.  Martin,  of  the  University 
of  Kansas. 

The  skull,  like  most  specimens  found  in  the  Niobrara  beds,  is  somewhat  crusht.  The 
length  from  the  snout  to  the  occipital  condyle  is  105  mm.;  to  the  end  of  the  supraoccipital 
spine,  143  mm.  From  the  outside  of  one  quadrate  to  that  of  the  other  is  loi  mm.  The  outline 
of  the  skull,  from  a  little  in  front  of  the  quadrate,  is  nearly  straight  to  the  rather  pointed  snout. 

Both  squamosals  (fig.  221)  are  missing,  but  it  is  probable  that  each  sent  upward  a  process 
to  the  parietal.    The  latter  bones  are  complete.    The  jugal  extended  nearly  to  the  pedicel  ot  the 


TOXOCHELYID^. 


175 


quadrate.  On  the  right  side  the  whole  of  the  quadratojugal  is  missing,  but  on  the  left  most  of 
it  is  present,  but  crusht.  The  interorbital  space  is  22  mm.  wide.  The  orbit  has  an  antero- 
posterior length  of  38  mm.    The  nasal  opening  is  15  mm.  wide. 

The  pterygoid  portion  of  the  palate  (fig.  222),  where  narrowest,  is  20  mm.  wide,  being 
narrower  than  in  T .  latiremis.  The  distance  between  the  ends  of  the  pterygoid  processes  is 
46  mm.;  whereas,  in  T.  latiremis  of  the  same  size,  the  distance  is  53  mm.  The  postpalatine 
foramina  have  a  diameter  of  5  mm.;  those  of  T.  latiremis,  a  diameter  of  13  mm. 


Pigs.  221  and  222. — Toxochelys  elkaJer.     Skull  of  type. 
221.  Upper  view.  222.  Lower  view. 

The  choanae  are  slightly  further  from  the  snout  than  in  T.  latiremis,  the  anterior  boundary 
being  28  mm.  away.  This  region  is  constructed  much  as  in  T.  procax,  but  the  choanae  are 
relatively  nearer  the  snout.  The  triturating  surface  of  the  upper  jaw  is  21  mm.  wide,  including 
a  roughened  ridge  5  mm.  wide  on  the  palatine. 

The  lower  jaw  (fig.  223)  is  apparently  somewhat  crusht  downward.  It  is  complete,  except 
that  both  articulars  appear  to  be  missing.  The  triturating  surface  looks  directly  upward,  is 
slightly  concave  transversely,  and  its  inner  border  overhangs  the  inner  face  of  the  bone.    The 

surface  is  15  mm.  wide  at  the  middle  of  the  length,  widening 
forward,  becoming  narrower  backward.  The  symphysis  has 
a  width  of  23  mm.,  both  above  and  below. 

So  far  as  is  to  be  seen,  the  plastral  bones  do  not  differ 
from  those  of  T.  serrifer.  One  coracoid  is  observed.  The 
length  is  85  mm.;  the  width  of  the  free  end,  48  mm.  The  bone 
is  therefore  both  shorter  [and  wider  Jthan  that  of  T.  latiremis. 
Some  of  the  ways  in  which  this  species  differs  from 
T.  latiremis  have  been  mentioned;  but  the  lower  jaws  are 
especially  different.  In  T.  latiremis  the  grinding-surface  is 
narrower  and  it  slopes  downward  and  inward  toward  the  inner 
face. 

T.  serrifer  differs  in  having  the  grinding-surface  more  con- 
cave from  front  to  back,  of  equal  width  from  end  to  end,  and 
the  superior  line  of  the  symphysis  equal  to  the  width  of  the 
grinding-surface,  and  to  the  lower  line  of  the  symphysis. 

In  T.  stenopora  the  triturating  surface  of  the  lower  jaw 
slopes  downward  and  inward  to  meet  the  inner  face  of  the  jaw.  The  upper  line  of  the  sym- 
physis slopes  downward  and  backward  and  is  somewhat  shorter  than  the  lower  line.  The 
nasal  opening  is  contracted.     The  length  of  the  prefrontal  suture  is  equal  only  to  one-halt 


Fig.  223. — Toxochelys  elkader. 
Lower  jaw  of  type,  with  section 
at  symphysis.     X^. 


176  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

the  interorbital  space,  whereas  in  T.  elkader  the  same  suture  is  equal  to  the  whole  width  of  the 
interorbital  space. 

T.  brachyrhina  is  a  species  with  a  blunter  snout,  a  narrower  lower  jaw,  and  a  much  shorter 
symphysis.    The  skull  is  narrower  behind  in  proportion  to  the  length. 

T.  procax  also  has  a  relatively  narrower  skull  and  the  choanse  are  placed  further  behind 

the  snout. 

T.  bauri,  having  been  founded  solely  on  portions  of  the  shell,  can  not  be  compared  with 
any  species  based  on  the  skull  alone. 

Toxochelys  procax  Hay. 

Figs.  2x4-228. 

Toxochelys  procax.  Hay,  Bull.  Amer.  Mus.  Nat.  Hist.,  xxi,  1905,  p.  181,  figs.  13,  14. 

The  type  of  the  present  species  is  a  large,  but  somewhat  damaged,  skull  which  belongs  to 
the  American  Museum  of  Natural  History,  New  York.  Its  number  is  234.  It  was  obtained 
from  Mr.  H.  T.  Martin,  who  collected  it  in  the  Niobrara  deposits  along  the  Smoky  Hill  River, 
in  Kansas,  in  1901.  On  the  lower  surface,  the  lateral  wings  of  the  pterygoids  are  broken  away; 
also  the  hinder  extremity  of  one  maxilla,  and  a  small  portion  of  the  palatines.  On  the  upper 
surface,  the  greater  part  of  the  frontals  and  parietals  is  gone,  as  well  as  the  whole  of  the  jugals. 


Figs.  224-228. — Toxochelys  procax.     Skull  and  lower  jaw. 


224.  Upper  aspect  of  anterior  portion  of  skull  of  type. 

225.  Skull  of  type,  showing  palatal  surface. 

226.  Tip  of  lower  jaw,  with  section  (226a)  along 

symphysis.    No.  234  A.  M.  N.  H. 

227.  Tip  of  lower  jaw.    No.  220  A.  M.  N.  H. 

228.  Dentary  bones.    No.  2050  Kansas  Univ. 

quadratojugals,  and  squamosals.    On  the  lower  jaw  there  are  present  a  portion  on  each  side 
of  the  symphysis  and  the  hinder  end  of  one  dentary. 

The  form  of  the  skull  (figs.  224,  225)  is  like  that  of  7".  latiremis,  except  that  the  outlines  of 
the  maxillse,  as  seen  from  below,  are  nearly  straight,  until  the  snout  is  approacht;  whereas 
in  T.  latiremis  the  whole  outline  is  convex.  The  skull  is  likewise  more  elongated  than  that  of 
T.  latiremis.    The  interorbital  space  is  27  mm.  wide;  and  the  pterygoids,  where  narrowest,  are 


TOXOCHELYIDiE. 


177 


22  mm.  wide,  taken  together.  In  T.  latiremis,  No.  1497  of  the  American  Museum,  with  skull 
only  two-thirds  as  long  as  the  type  of  T.  procax,  the  interorbital  space  is  20  mm.  and  the  ptery- 
goids are  23  mm.    T.  procax  is  therefore  characterized  by  a  very  narrow  palate. 

The  most  important  character  for  differentiating  this  species  from  T.  latiremis  is  found  in 
the  lower  jaw.  As  shown  by  the  symphyseal  portions  of  the  dentaries,  the  alveolar  surface  is  very 
broad,  horizontal,  and  very  slightly  concave.  In  the  midline  this  surface  extends  as  far  back- 
ward as  does  the  symphysis  on  the  lower  side  of  the  jaw;  whereas  in  T.  latiremis  the  alveolar 
surface  extends  backward  little  more  than  half  as  far  as  the  lower  face  of  the  bone. 

From  the  type  of  Cope's  T.  serrifcr  this  species  is  likewise  distinguisht  by  the  width  of  the 
symphyseal  portion  of  the  alveolar  surface.  In  T.  serrifer  the  surface  extends  backward  nearly 
as  far  as  does  the  lower  surface  of  the  bone;  but  the  width  above  is  contained  in  the  length  of  the 
alveolar  surface  nearly  5  times,  whereas,  in  T .  procax,  it  is  contained  only  2.5  or  3  times.  The 
inner  face  of  the  dentary  is  furthermore  much  deeper  proportionally  in  T.  serrifer  than  in 
T.  procax.  From  T .  brachyrhtna  this  species  differs,  so  far  as  known,  in  having  a  more  pointed 
head  and  a  still  narrower  pterygoid  region.  The  lower  jaws  of  the  two  can  not  yet  be  com- 
pared. From  T.  stenopora  the  present  species  differs  in  a  much  wider  narial  orifice  and  in  the 
character  of  the  lower  jaw,  as  well  as  in  various  other  respects.  T.  elkaJer  has  a  relatively 
broader  skull  and  choanae  not  so  far  removed  from  the  snout.  The  lower  jaws  of  the  two  species 
appear  to  be  greatly  alike. 

The  length  of  the  skull  of  the  type  of  T.  procax  is  165  mm.  from  the  tip  of  the  snout  to  the 
occipital  condyle.  The  distance  between  the  outer  faces  of  the  quadrates  is  138  mm.  Seen 
from  below  the  skull  is  wedge-shaped,  and  the  snout  rather  pointed.  The  anterior  narial 
opening  is  of  the  usual  form.     Little  can  be  said  regarding  the  upper  surface  of  the  skull. 

The  alveolar  surface  of  the  upper  jaw  (fig.  225)  is  broad,  and  a  strongly  developt  and  very 
rough  ridge  starts  from  the  premaxilla  and  runs  backward,  first  on  the  premaxilla,  then  on  the 
palatine.  Between  the  anterior  ends  of  these  ridges  there  runs  a  deep  median  groove.  The 
palatine  bones  encroach  more  on  the  choanae  than  they  do  in  T.  latiremis,  so  that  these  orifices 
resemble  somewhat  those  of  Chelonta.  The  alveolar  surfaces  are  fully  as  broad  at  the  anterior 
ends  of  the  choanae  as  they  are  posteriorly;  whereas  in  T.  latiremis  they  widen  posteriorly. 
There  is  a  deep  pit  in  the  midline  on  the  lower  surface  of  the  premaxillae,  from  which  we  may 
infer  that  the  lower  jaw  bore  a  sharp  horny  beak.  The  cutting-edges  of  the  maxillae  descend 
but  little  below  the  level  of  the  alveolar  surfaces. 

The  tympanic  cavity  appears  to  have  had  about  the  same  degree  of  development  that  we 
find  in  Caretta. 

At  the  symphysis  (fig.  226)  the  alveolar,  or  masticatory  surface,  extends  backward  as  far 
as  does  the  lower  face  of  the  bone,  and  each  measures  32  mm.  The  alveolar  surface  is  slightly 
concave  on  each  side  of  a  low  median  ridge,  which  forks  posteriorly.  The  symphysis  has  a 
thickness  of  but  12  mm.,  which  thinness  may  be  due  slightly  to  compression,  but  this  is  doubt- 
ful. The  groove  on  the  inner  face  of  the  dentary  continues  to  the  symphysis.  Fig.  227  repre- 
sents another  jaw  fragment  in  the  American  Museum.    Its  number  is  220. 

No.  2050  of  the  Kansas  University  furnishes  the  united  dentaries  of  this  species  (fig.  228), 
but  it  has  belonged  to  a  smaller  specimen  than  the  type.  A  small  portion  has  been  broken  from 
the  tip.  The  total  length  of  one  dentary  is  80  mm.  The  width  of  the  masticatory  surface  at 
the  symphysis  is  24  mm.,  and  it  extends  as  far  backward  as  the  symphysis  does  on  the  lower 
side  of  the  jaw.  The  thickness  of  the  bone  at  the  hinder  end  of  the  symphysis  is  9  mm.,  but 
in  life  this  may  have  been  greater.  The  masticatory  surface  is  broad  and  flat,  but  narrows 
posteriorly.  Both  the  inner  and  the  outer  borders  are  sharp,  the  latter  overhanging  the  groove 
along  the  inner  face  of  the  bone.    The  groove  just  referred  to  passes  forward  to  the  symphysis. 

The  writer  has  been  enabled  to  examine  a  skull  and  lower  jaw  of  this  species,  which  belongs 
to  the  University  of  Chicago.  Its  catalog  number  is  572.  The  exact  locality  in  Kansas  is 
unknown.  The  skull  is  117  mm.  long  from  the  snout  to  the  condyle.  The  upper  surface  is 
damaged  to  the  same  extent  as  in  the  type  specimen.  The  masticatory  surface  of  the  lower 
jaw  extends  backward  60  mm.  from  the  tip  of  the  jaw.  Anteriorly  it  is  somewhat  concave, 
but  along  the  symphysis  there  is  a  rather  prominent  ridge.  The  thickness  of  the  jaw  at  the 
hinder  end  of  the  symphysis  is  10  mm. 

12 


.78 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


Toxochelys  bauri  Wieland. 

Figs.  229-230. 
Toxochelys  btitiri,  WiELAND,  Amer.  Jour.  Sci.,  XX,  1905,  p.  .^25,  plate  x,  text-figs.  1-8. 

Up  to  the  present  time  no  better  carapace  of  a  Toxochelys  has  been  recovered  than  that 
forming  the  basis  of  Wieland's  Toxochelys  bauri.  This  specimen  forms  No.  2823  of  the  Yale 
University  collection.  It  was  found  in  the  Niobrara  deposits,  near  Monument  Rocks,  Gove 
County,  Kansas.  It  furnishes  all  the  neurals,  and  the  nuchal;  large  portions  of  all  the  costals 
of  the  right  side,  except  the  fifth;  the  proximal  ends  of  all  the  costals  of  the  left  side;  all  the 
peripherals  of  the  right  side,  except  the  fifth  to  the  eighth  inclusive;  all  of  those  of  the  left  side, 
except  the  first  three  and  the  seventh,  ninth,  and  eleventh.  Of  the  plastron  there  is  present 
a  considerable  part  of  the  right  hyoplastron  and  hypoplastron.  A  number  of  Wieland's  figures 
are  here  reproduced. 

As  to  the  distinctness  of  this  species  from  all  that  have  hitherto  been  described  there  may  be 
doubts,  which  it  is  too  early  to  remove.    Of  two  of  the  described  species,  T.  brachyrhina  and 


Fig.  229. — Toxochelys  bauri.     Carapace  of  the  type.      X». 

c.  p.  I,  c.  p.  1,  c.  p.  8,  first,  second  and  eighth  costal  plates;  /,  fontanels  behind  nuchal;  n.  1,  n.  2,  etc.,  the  neural 
bones;  nu.p,  nuchal  plate;  per.  10,  the  tenth  peripheral;  py,  pygal  bone;  spy.  i,  spy.  2,  spy.  3,  the 
suprapygal  bones.      Or,  spy.  i  may  be  the  ninth  neural;  spy.  2  and  spy.  3,  first  and  second  suprapygals. 

T.  procax,  no  portions  of  the  shell  are  known;  and  T.  bauri  may  be  the  shell  of  one  of  these. 
Of  T.  latiremis  only  small  portions  of  the  shell  are  known;  but  to  judge  from  the  figures  of  the 
nuchal  that  have  been  publisht,  the  species  is  distinct  from  T.  bauri.  The  latter  appears  pretty 
certainly  to  be  distinct  from  T.  stenopora.  Of  the  carapace  of  T.  serrifer  Cope  there  are  known 
only  two  peripherals,  apparently  the  eighth  and  the  ninth.  These  appear  to  resemble  greatly 
the  same  peripherals  of  Wieland's  species.  They  belonged  to  an  individual  about  half  the 
size  of  the  latter.  The  eighth  of  Wieland's  type  had  a  length  of  80  mm.  and  a  width,  at  the 
notch,  of  45  mm.;  the  ninth,  a  length  of  75  mm.  and  a  width  of  45  mm.  The  eighth  oiT .  serrifer 
is  41  mm.  long  and  25  mm.  wide;  the  ninth,  43  mm.  long  and  27  mm.  wide.    It  will  be  seen  that 


TOXOCHELYID^. 


179 


the  latter  two  peripherals  are  slightly  wider  proportionally  than  are  those  of  T.  bauri.  As 
regards  the  thickness  no  definite  statements  can  be  made  about  either  species,  but  both  appear 
to  resemble  the  corresponding  peripherals  of  Lytolomn. 

The  carapace  of  T.  bauri  has  a  length  of  about  530  mm. ;  its  greatest  width,  when  restored 
to  what  is  regarded  as  its  original  form,  is  about  400  mm.  The  species  was  therefore  of  consid- 
erable size  and  the  form  was  relatively  narrow.  In  front  the  outline  is  concave  along  the  nuchal; 
while  the  rear  is  rounded.  There  are  no  excavations  over  the  anterior  limbs,  such  as  are  seen 
in  the  modern  Cheloniidae. 

This  carapace  is  composed  of  8  pairs  of  costals,  a  nuchal,  9  neurals,  apparently  3  suprapy- 
gals,  a  pygal,  and  11  pairs  of  peripherals.  The  first,  second,  and  tenth  peripherals  had  no 
connection  with  the  costals.  The  others  received  each  the  extremity  of  a  rib  in  a  pit.  In  all, 
except  the  third  and  the  eleventh,  this  pit  is  nearest  the  hinder  end  of  the  peripheral.  There 
are  large  costo-peripheral  fontanels,  which  extended  from  the  peripherals  half-way  to  the 
neurals.  Besides  these  vacuities,  there  is  a  small  one  on  each  side  at  the  common  meeting- 
place  of  the  nuchal,  the  first  costal,  and  the  first  neural.  Similar  vacuities  are  found  in  a  few 
of  the  Trionychidae. 

The  accompanying  table  shows  the  dimensions  of  the  neurals,  taken  from  Wieland's 
description  of  the  species.    The  forms  may  be  determined  from  fig.  229. 


Neural. 

Length. 

Width.    ' 

I 

38 

38       i 

1 

44 

37 

3 

44 

40 

4 

46 

♦+        ( 

5 

34 

+5       i 

6 

50 

40       1 

7 

40 

38 

8 

25 

35 

9 

'S 

35 

Fig.  230. — Toxochelys   bauri.     Shell   presenting   left   side.      Xn. 

/,  fontanels  behind  the  nuchal;   i,  5, 5,  series  of  ossicles  surmounting  certain  of  the 
neural  bones.    Reproduced  from  figure  by  Wieland, 

It  seems  evident  that  an  extra  neural  was  intercalated  in  the  series.  This  is  shown  by  the 
fact  that,  as  the  series  runs,  most  of  them  are  crowded  somewhat  out  of  their  natural  positions, 
being  nearly  as  much  in  contact  with  the  costals  in  front  of  them  as  with  those  to  which  they 
belong.  This  intercalation  is  shown  in  another  way.  There  is  a  series  of  ossicles,  4  in  number, 
along  the  midline — ossicles  which  Wieland  calls  epineurals.  The  first  forms  a  slight  boss  on 
the  first  neural.  The  second  lies  across  the  suture  between  the  third  and  the  fourth  neurals; 
the  third,  across  the  suture  between  the  fifth  and  the  sixth  neurals;  the  fourth  rests  on  the 
eighth  and  ninth  neurals  and  the  first  suprapygal.  This  arrangement  does  not  agree  with 
that  appearing  to  exist  in  the  other  specimens  of  this  genus  which  have  furnisht  the  neurals. 
Moreover,  it  does  not  correspond  with  the  usual  arrangement  of  the  horny  scutes  of  turtles.  In 
the  specimen  described  by  the  writer  in  the  American  Naturalist  (xxxii,  1898,  p.  936)  and  in 
the  specimen  here  described  on  page  i64,a  sulcus  passes  behind  each  of  the  tubercles  surmount- 
ing the  neurals.  This  sulcus  in  each  case  separates  two  of  the 
vertebral  scutes.  Now,  almost  without  exception,  the  first  sulcus 
crosses  the  first  neural,  the  second  crosses  the  third  neural,  the 
third  traverses  the  fifth  neural.  The  position  of  the  fourth  trans- 
verse sulcus  varies  somewhat,  but  it  is  usually  found  on  the  eighth 
neural.  In  the  present  specimen  the  sulci  must  have  crost  on  the 
first,  the  fourth,  the  sixth  neurals  and  the  first  suprapygal.  It 
seems  evident  that  it  is  the  third  neural  of  the  series  that  is  an 
intruder  and  disturber.  In  a  specimen  of  Colpochelys  kempi,  in 
the  American  Museum  of  Natural  History,  there  are  all  together 
13  neurals.  The  sulci  cross  on  the  first,  the  fourth,  the  eighth, 
and  the  twelfth  neurals. 

The  nuchal  bone  has  a  width  of  120  mm.  along  the  free 


Peripheral. 

Length. 

Width. 
»5 

60 

5° 

*5 

59 

28 

60 

65 

28 

70 

33 

7 

75 

8 

80 

45 

9 

75 

45 

10 

70 

45 

II 

68 

45 

l8o  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

border;  a  maximum  width  of  145  mm.  Its  fore-and-aft  extent  is  55  mm.  The  table  gives  the 
dimensions  of  the  peripherals.  The  width  is  taken  at  the  notch  of  each  where  the  sulcus  crost 
the  free  border. 

On  account  of  considerable  crushing  the  thickness  has  not  been  given.  We  are  informed 
by  Wieland  that  transverse  sections  are  approximately  as  in  the  peripherals  of  Lytoloma 
angusta  (  =  /..  ^vielandi). 

The  pygal  measures  65  mm.  along  the  free  border  and  45  mm.  along  the  midline. 

The  reader  is  referred  to  page  165  for  remarks  on  the  connection  of  the  rib  of  the  eighth 
costal  plate  with  the  eleventh  peripheral  of  this  species. 

Genus  CYNOCERCUS  Cope. 

A  genus  based  on  caudal  vertebrae  and  a  medapodial.  Caudals  procoelous  and  provided 
with  chevrons.    The  articular  cup  with  a  median  perpendicular  groove  or  incision. 

Type:  Cynocercus  incisus  Cope. 

This  little-known  genus  is  placed  in  the  present  family  because  of  the  possibility  that  it  is 
identical  with  Toxochelys. 

Cynocercus  incisus  Cope. 

Cynocercus  incisus,  CoPE,  Proc.  Amer.  Philos.  See,  xil,  1872,  p.  jo8;  Proc.  Acad.  Nat.  Sci.  Phila.  1872, 
p.  129;  Fifth  Ann.  Report  U.  S.  Geol.  Surv.  Mont.,  etc.,  1871  (1872),  p.  ;?J5;  Vert.  Cret.  Form. 
West,  1875,  pp.  96,  260,  plate  viii,  figs.  3-5. — Williston,  Univ.  Geo).  Surv.  Kansas,  iv,  1898, 
p.  368,  fig.  6. — Hay,  Pubs.  Field  Columb.  Museum,  Zool.,  i,  1896,  p.  106;  Bibliog.  and  Cat.  Foss. 
Vert.  N.  A.,  1902,  p.  442. 

Cynocercus  incisus  was  based  on  two  caudal  vertebrae  and  a  metapodial.  These  were 
found  by  Cope  in  the  yellow  chalk,  probably  the  Niobrara,  near  Butte  Creek,  south  of  Wallace, 
Kansas.  These  bones  are  now  in  the  American  Museum  of  Natural  History  and  have  the 
number  1582.    It  is  not  known  whether  the  metapodial  belongs  to  the  fore  or  the  hinder  foot. 

The  vertebrae  were  fully  described  and  figured  by  Cope  as  cited  above.  Williston  repro- 
duced a  portion  of  the  description  and  the  figures  of  the  vertebrae.  The  reader  is  referred  to 
these  authors.  It  may  be  here  stated  that  the  length  of  the  centrum  of  each  of  these  vertebrae 
is  27  mm.,  a  fact  showing  that  the  animal  must  have  been  of  considerable  size.  They  did  not 
belong  among  the  most  anterior,  for  they  possest  chevrons.  Cope  stated  correctly  that  they 
differ  from  those  of  Chelydra  in  being  procoelous.  They  differ  further  from  those  of  the  latter 
genus  in  being  more  comprest  and  in  having  higher  neural  arches.  Cope  suggested  a  resem- 
blance to  those  of  the  Trionychoidea.  From  the  latter  they  difl^er  in  possessing  chevrons  and 
in  having  the  transverse  processes  attacht  to  the  centrum.  The  vertebrae  of  the  anterior  half  of 
the  tail  of  soft-shelled  turtles  have  high  neural  arches;  from  these  spring  transverse  processes. 

What  appears  to  distinguish  these  caudals  from  those  of  any  other  known  genus  is  the 
presence  of  a  sharp  groove,  or  incision,  running  perpendicularly  down  the  middle  of  the  articu- 
lar cup.  It  has  been  suggested  by  more  than  one  author  that  these  vertebrae  are  those  of 
some  species  of  Toxochelys;  but  this  has  not  yet  been  proved. 

Genus  PORTHOCHELYS  Williston. 

Skull  as  broad  as  long.    Nasal  bones  present.    Lateral  fontanels  of  the  carapace  obsolete. 
All  of  the  peripherals  articulating  closely  with  the  costals.    No  carina  along  the  middle  of  the 
back  and  no  tubercles.    Plastron  with  small  median  and  lateral  fontanels. 
Type  :  Porthochelys  laticeps  Williston. 

Porthochelys  laticeps  Williston. 

Plate  31,  figs.  2,  3;   text-figs.  231-234. 

Porthochelys  laticeps,  Williston,  Trans.  Kansas  Acad.  Sci.,  xvii,  B,  1901,  p.  195,  plates  xviii-xxii. 
Hay,  Bull.  Amer.  Mus.  Nat.  Hist,  xxi,  1905,  p.  183. 

The  type  of  this  fine  species  is  the  property  of  Kansas  University  and  was  collected  in  the 
Niobrara  beds,  on  the  Saline  River,  in  Trego  County,  Kansas.  The  remains  comprize  the 
greater  portion  of  the  skull,  nearly  the  whole  of  the  left  side  of  the  carapace,  the  whole  of  the 


TOXOCHELYID^:. 


iSl 


plastron  (except  the  epiplastia  and  the  entoplastron)  and  the  right  humerus.  From  the  portion 
of  the  carapace  present  the  whole  has  been  restored,  as  seen  in  Professor  Williston's  original 
description.  The  figures  presented  in  the  present  work  have  been  redrawn,  with  slight  modi- 
fications, from  Williston's  paper. 

The  skull  (figs.  231,  232)  is  remarkable  for  its  breadth  and  the  massiveness  of  the  jaws. 
As  shown  by  the  figures,  the  posterior  breadth  is  maintained  with  slight  diminution  far  forward, 
so  that  the  head  appears  very  blunt,  altho  the  snout  is  somewhat  produced.  The  narial 
opening  is  broader  than  high,  and  its  upper  boundary  is  furnisht  mostly  by  a  pair  of  small 
nasals.  The  orbits  are  rather  large  and  directed  rather  strongly  upward.  The  interorbital 
space  is  19  mm.  wide.    The  bones  covering  the  temporal  region  are  so  much  damaged  that  the 


Figs.  231  and  232. — Porthochelys  laticeps.     Skull  of  type. 

251.  Upper  surface.  232.  Palatal  surface. 


Xi. 


extent  of  the  roof  can  not  be  determined;    but  it  was  probably  as  extensive  as  in  Toxochelys. 
The  bones  of  the  upper  surface  of  the  skull  are  much  roughened,  as  in  Chelydra. 

The  palatal  surface  of  the  skull  is  shown  in  fig.  232.  The  cutting-edge  of  the  maxilla  is 
deeper  than  in  Toxochelys  latiremis,  and  its  depth  increases  toward  the  jugal  bone.  The  palatal 
surface  of  the  bone,  10  mm.  wide  in  front,  increases  to  20  mm.  at  the  hinder  end.  The  masti- 
catory surface  extends  over  on  the  palatine  and  is  markt  internally  by  a  rough  ridge.  Trans- 
versely the  surface  is  slightly  concave.  The  choanae  are  not  encroached  on  by  plates  from  the 
vomer  and  palatines,  as  they  are  in  the  Cheloniidae,  but  lie  well  forward  in  a  shallow  fossa. 
They  are  separated  by  the  vomer,  which  is  wide  anteriorly,  narrow  between  the  choanae,  and 
develops  a  sharp  ridge  on  its  palatal  surface.    As  in  Chelydra,  each  pterygoid  developt  a  strong 

lateral  process,  against  which  the  mner  surface  of  the 
dentary  workt.  The  width  of  the  pterygoids,  where 
narrowest,  is  30  mm.  The  quadrates  are  notcht  behind 
for  the  passage  of  the  columella,  as  in  Toxochelys. 

Of  the  mandibles  only  the  united  dentaries  are  pres- 
ent (fig.  233).  They  are  very  heavy  and  strong  bones. 
The  masticatory  surface  is  somewhat  concave  both  trans- 
versely and  longitudinally,  and  is  bounded  internally 
along  the  anterior  half  by  a  rough  ridge.  At  the  sym- 
physis the  two  ridges  unite  and  run  to  the  front  of  the 
jaw.  This  masticatory  surface  is,  in  front,  only  about 
half  as  wide  as  is  the  symphysis  itself;  but  it  widens 
backward  and  overhangs  the  inner  lower  border  of  the 
jaw.  The  coronoid  process  is  considerably  elevated, 
ipace  (plate  31,  fig.  2;  text-fig.  234)  is  now  very  flat.  How  deprest  it  was  during 
ossible  now  to  say;   but  it  probably  had  no  great  elevation.    It  is  nearly  circular, 


Fig.  233. — Porthochelys  laticeps.  Den- 
tary bones  of  type.  Xi-  Redrawn 
from  Williston's  figure.  Showsgrind- 
ing-surfaces. 


The  carap 
life  it  is  impossible  now  to  say; 


1 82 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


the  width  being  785  mm.,  the  length  only  730  mm.  The  border  appears  to  have  been  slightly 
excavated  in  front,  elsewhere  somewhat  repand.  The  costal  plates  are  so  extensively  ossified 
that  there  now  remain  only  insignificant  fontanels  at  their  outer  ends.  The  greater  portion  of 
the  nuchal  bone  is  missing.  The  peripherals  are  eleven  in  number  on  each  side.  They  are 
rather  narrow  in  front  but  their  width  increases  posteriorly,  and  they  become  quite  thick. 
The  sixth  from  the  front  is  equal  in  width  to  one-eighth  of  the  width  of  the  carapace;  the  eighth 
is  a  little  more  than  one-sixth  of  the  width  of  the  carapace. 

Of  the  neurals  the  fifth  and  sixth  are  wholly  wanting,  while  the  fourth  and  seventh  are 
represented  each  by  only  a  small  portion.   Those  present  are  narrow,  about  30  mm.  wide.   The 

second,  third,  and  fourth  have  their  anterior  outer  angles 
cut  off  by  contact  with  the  costals  in  advance.  The 
neurals  are  smooth,  and  without  trace  of  the  tubercles 
which  are  so  conspicuous  in  Toxochelys.  There  are  two 
suprapygals,  each  forming  a  symmetrical  trapezoid,  and 
these  are  placed  base  to  base. 

Dermal  scutes  were  present,  and  are  indicated  by  very 
distinctly  markt  sulci.  The  vertebrals  are  narrow,  the 
third  and  fourth  being  about  one-seventh  as  wide  as  the 
shell.  The  first  is  slightly  wider;  the  fifth  has  a  width 
equal  to  one-fourth  the  width  of  the  shell.  The  mar- 
ginal scutes  lie  almost  wholly  on  the  peripheral  bones. 
The  plastron  (plate  31,  fig.  3)  resembles  greatly  that 
of  Toxochelys.  There  were  small  central  and  lateral 
fontanels.  Probably  the  right  and  left  halves  of  the 
plastron  approacht  each  other  more  closely  than  is 
shown  in  the  figure.  The  thickness  of  the  hyoplastron 
and  hypoplastron  where  they  join  is  from  10  to  12  mm. 
They  are  thin  and  serrated  along  the  median  border. 
The  right  humerus  accompanies  the  remains,  but  the 
ulnar  process  is  broken  away.  The  bone  is  flattened, 
mostly  as  a  result  of  compression  during  burial.  It 
appears  to  have  resembled  closely  the  corresponding  bone 
oi  Toxochelys;  but  the  radial  process  has  been  directed 
more  strongly  toward  the  ulnar  side.  The  total  length  of 
the  bone  was  140  mm.  The  position  and  extent  of  the 
epicondylar  groove  and  of  the  condyles  for  the  radius  and  ulna  seem  to  have  been  the  same  as 
in  Toxochelys.  Two  cervical  vertebrae,  a  small  portion  of  the  scapula,  and  a  claw  are  mentioned 
by  Williston  as  furnishing  no  important  differences  when  compared  with  those  of  Toxochelys. 
In  general  appearance  this  turtle  differs  greatly  from  Toxochelys.  The  head  is  of  heavier 
construction  and  of  blunter  form;  there  are  nasals;  the  carapace  is  circular,  instead  of 
elongated  and  pointed  behind;  it  is  more  extensively  ossified;  and  there  is  no  carina  along  the 
middle  of  the  back.  Otherwise  Porthochelys  agrees  with  Toxochelys.  As  already  remarkt, 
the  presence  of  nasals  is  regarded  as  being  of  no  more  than  generic  value. 

Porthochelys  browni  Hay. 
Figs.  235-237. 
Porthochelys  browni,  Hay,  Bull.  Amer.  Mus.  Nat.  Hist,  xxi,  1905,  p.  183,  figs.  15,  16. 

The  type  of  this  species  was  collected  during  the  summer  of  1903,  by  Mr.  Barnum  Brown 
of  the  American  Museum  of  Natural  History,  in  deposits  shown  by  their  invertebrate  fossils 
to  belong  to  the  Pierre  formation.  The  locality  is  20  miles  southeast  of  Edgemont,  South 
Dakota.    The  catalog  number  of  the  specimen  is  6080. 

The  specimen  presents  the  skull  and  the  lower  jaw  nearly  complete,  some  pelvic  bones, 
one  humerus,  one  scapula,  a  femur,  and  some  other  limb  bones.  Unfortunately  most  of  the 
bones  are  crusht  nearly  flat  and  were  covered  with  a  layer  of  gypsum.  Altho  the  skull  is  consid- 
erably crusht,  the  most  essential  elements  of  its  construction  may  be  determined. 


Fig.  234. — Porthochelys  laticeps.  Cara- 
pace of  type.  X  i.  Restored  por- 
tions indicated  by  dotted  lines. 


TOXOCHELYID^,. 


183 


The  skull  is  broad  and  it  was  probably  originally  considerably  deprest,  but  to  what  extent 
the  present  flatness  is  due  to  pressure  can  not  be  determined.  The  outlines  as  seen  from  above 
(%•  235)  are  greatly  like  those  of  Porthochelys  laticeps,  but  the  skull  of  the  present  species 
is  longer  than  broad.  The  sides  of  the  skull  converge  slowly  to  the  front  of  the  orbits,  where  the 
width  is  still  100  mm.,  then  rapidly  approach  the  tip  of  the  snout.  The  outline  is  such  that  the 
snout  appears  somewhat  produced.  The  occipital  condyle  is  broken  away,  but  from  its  esti- 
mated position  to  the  end  of  the  snout  is  160  mm.;  from  the  end  of  the  supraoccipital  spine  to 
the  snout,  190  mm.  The  breadth  from  the  outside  of  one  quadrate  to  that  of  the  other  is  142 
mm.  The  bones  of  the  upper  surface  of  the  skull  are  smooth,  whereas  those  of  P.  laticeps  are 
ridged  and  grooved.  The  temporal  region  is  rooft  over  not  quite  as  far  backward  as  the 
hinder  borders  of  the  exoccipitals  and  paroccipitals,  so  that  the  latter  bones  are  seen  from  above. 
Hence,  the  roof  is  not  so  extensive  as  in  Chehnia  mydas,  but  about  as  complete  as  in  Carettn. 


Fig.  235. — Porthochelys  browni.     Skull  of  type,  upper  aspect,      xi.     No.  6080  A.  M.  N.  H. 
fr,  frontal;  ju,  jugal;   mx,  maxilla;   pa,  parietal;  pof,  postfrontal;   />rf,  prefrontal;   sq,  squamosal. 

The  eyes  of  this  turtle  were  evidently  directed  strongly  upward  as  well  as  outward.  The 
distance  from  the  middle  of  the  lower  part  of  the  rim  of  one  orbit  to  that  lof  the  other  is  90  mm. 
The  width  of  the  interorbital  space  is  30  mm.  If  now  the  middle  of  the  interorbital  space 
stood  50  mm.  above  the  roof  of  the  mouth  the  plane  of  the  orbits  would  stand  at  an  angle  of 
45°  with  the  horizontal.  It  is  not  probable  that  the  elevation  of  the  skull  was  greater  than  that 
supposed.  The  longitudinal  diameter  of  the  orbit  is  50  mm.  The  transverse  diameter  of  one 
is  now  33  mm.,  of  the  other  30  mm.  If  the  elevation  of  the  skull  was  originally  50  mm.  above 
the  roof  of  the  mouth  the  transverse  diameter  of  the  orbit  must  have  been  about  43  mm.  It 
is  not  likely  to  have  been  more.  Hence,  we  seem  to  be  justified  in  believing  that  the  eyes  were 
directed  strongly  upward. 

It  is  evident  that  the  nasal  opening  was  higher  than  wide.  Its  present  width  is  19  mm.,  its 
height  21  mm.   The  distance  from  the  orbit  to  the  hinder  border  of  the  temporal  roof  is  53  mm. 

The  anterior  borders  of  the  choanae  are  placed  43  mm.  behind  the  tip  of  the  snout  (fig.  236). 
The  palatines  appear  to  have  joined  the  vomer,  as  in  Toxochelys.  The  crushing-surfaces  of 
the  upper  jaws  have  a  width  of  about  27  mm.  They  are  concave  from  the  cutting-edge  of  the 
jaw  to  the  palatines.     The  width  of  the  combined  pterygoids,  where  narrowest,  is  39  mm. 


184 


FOSSIL    TURTLES    OF    NORTH    AMFRICA. 


The  lower  jaw  (fig.  237)  is  nearly  complete.  The  crushing-surface  has  a  width  of  18  mm. 
and  is  convex  transversely.  The  cutting-edge  is  acute  and  directed  outward,  possibly  due 
partly  to  distortion.  The  tip  of  the  jaw  appears  to  have  been  somewhat  upturned  as  a  beak, 
and  there  is  a  corresponding  pit  in  the  upper  jaw  just  behind  the  premaxillae.  The  symphysis 
has  a  length  of  35  mm. 

The  humerus  is  crusht  very  flat  and  the  ulnar  process  is  broken  off.  The  length  of  the  bone, 
measured  from  the  proximal  surface  of  the  head  to  the  distal  end,  is  156  mm.    The  impression 


Figs.  256  AfiD z^J.-Porthochelys  hrowni. 
Skull  and  lower  jaw  of  type.      Xj. 

236.  Palatal  surface,  m.v,  maxilla;  palf  palatine; 
pt,  pterygoid;   qUj  quadrate;   z?om,  vomer. 

237.  Lower  jaw.  ang^  angular;  art,  articular; 
dartf  dermarticular;  den,  dentary;  sur, 
supraangular. 

of  nearly  the  whole  head  appears  on  the  upper  side  of  the  flattened  bone;  hence  it  is  evident 
that  the  head  was  directed  upward  when  the  bone  was  horizontal  and  not  as  it  is  in  the 
Cheloniidae.  The  radial  process  was  connected  with  the  head  and  there  existed  a  broad  exca- 
vation, or  fossa,  between  this  process  and  the  ulnar  process.  In  short,  the  humerus  appears 
to  have  had  practically  the  form  of  that  of  Chelydra. 

The  distal  end  of  the  femur  is  missing,  but  the  bone  was  at  least  nearly  as  long  as  the 
humerus.    It  was,  however,  a  slenderer  bone. 

The  ilium  resembles  closely  that  of  Toxochelys. 

Family  DESMATOCHELYIDyE  Williston. 

Skull  with  temporal  region  rooft  over  as  far  backward  as  the  occipital  condyle.  Large 
nasal  bones  present.  Choanae  placed  well  foi-ward,  not  underfloored  by  the  vomer,  maxillae, 
and  palatines.  Small  posterior  palatine  foramina  present.  Humerus  indicating  a  paddle-like 
fore  limb.    Plastron  loosely  joined  to  the  carapace. 

The  type  of  this  family  is  the  genus  Desmatochelys,  but  the  genera  Atlantochelys  and 
Neptunochelys  are  provisionally  included.  The  two  latter  are  known  only  from  humeri. 
These  are  not  greatly  different  from  the  same  bones  in  the  Cheloniidae. 

Genus  DESMATOCHELYS  Williston. 

Desmatochelys,  WiLLlSTON,  Kansas  Univ.  Quart.,  in,  1894,  p.  5. 
Desmochelys,  BouLENGER,  Zool.  Record,  Reptiles,  1895,  p.  29. 

The  generic  characters  are  not  yet  to  be  distinguisht  from  those  of  the  family. 
The  type  of  the  genus  is  Desmatochelys  lowi  Williston. 


DESMATOCHELYIDiE. 


185 


This  genus  is  a  most  interesting  one,  inasmuch  as  it  shows  evident  relationships  with  the 
Cheloniidae,  and  at  the  same  time  presents  characters  which  must  be  regarded  as  more  primitive 
than  those  of  the  latter  family.  Among  these  characters  is  the  possession  of  well-developt 
nasal  bones.  The  choanae  too  have  their  primitive  position  just  behind  the  premaxillae  and  are 
separated  by  the  body  of  the  vomer.  In  the  Cheloniidae  the  latter  bone  sends  downward  a 
perpendicular  plate,  the  lower  border  of  which  expands  laterally  and  joins  horizontal  plates 
of  the  maxillae  and  of  the  palatines,  forming  a  floor  beneath  the  narial  passages  and  pushing 
the  choanae  further  backward.  The  possession  of  small  posterior  palatine  foramina  shows  a 
closer  connection  with  Amphichelydian  stock  than  exists  in  the  Cheloniidae,  which  have  lost 
these  foramina. 

Williston  thinks  that  the  cervical  vertebrae  indicate  pleurodiran  characters.  The  posses- 
sion of  strongly  developt  transverse  processes  is  to  be  regarded  as  an  inheritance  rather  trom 
the  Amphichelydia  than  from  the  Pleurodira.  The  articular  ends  of  the  cervical  vertebrae 
show  decided  aflinities  with  the  Cryptodira.  An  intervertebral  articulation  which  is  26  mm. 
wide  and  only  15  mm.  high,  belonging  to  a  centrum  only  26  mm.  long,  would  not  lend  itself 
readily  to  flexure  sidewise,  while  it  would  permit  easy  flexure  in  a  perpendicular  plane. 

The  Desmatochelyidae  are  to  be  arranged  close  to  the  Cheloniidae;  but  their  many  prim- 
itive characters  demand  that  they  be  kept  in  a  distinct  family.  For  those  who  are  seeking  a 
Cretaceous  ancestor  for  the  modern  sea-turtles,  Desmatochelys  presents  itself  as  a  more  eligible 
form  than  any  of  the  Cretaceous  Thalassemydidae. 


Figs.  238  and  239. — Desmatochelys  lowi.     Skull  of  type.     Xj. 
238.  Upper  surface.  239.  Seen  from  below. 


Desmatochelys  lowi  Williston. 

Figs.  238-243. 

Desmatochelys  lowii,  Williston,  Kansas  Univ.  Quart.,  ill,  1894,  p.  5;   Univ.  of  Kansas  Geol.  Surv., 
IV,  1898,  p.  353,  plates  Ixxiii-ixxviii. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  443. 

The  original  and  only  known  materials  belonging  to  the  present  species  are  the  property 
of  the  University  of  Kansas.  They  consist  of  the  skull,  finely  preserved,  but  lacking  the  hinder 
part  of  the  base;  3  cervical,  the  sacral,  and  some  caudal  vertebrae;  the  pectoral  girdle,  the 
humerus,  radius,  and  some  metacarpal  bones;  most  of  the  pelvic  bones  and  an  incomplete 
femur;  some  fragments  of  the  carapace  and  some  of  the  plastron.  The  animal  was  apparently 
preserved  in  fine  condition,  but  was  damaged  in  collecting.    The  remains  were  found  in  Benton 


1 86 


KOSSIL    TURTLES    OF    NORTH    AMKRICA. 


deposits,  near  Fairbury,  Nebraska.  An  extended  description  of  the  species,  with  figures,  is 
given  by  Williston,  as  cited  above.  A  number  of  his  drawings  have  been  reproduced  in  the 
present  work. 

This  turtle  was  evidently  a  large  one.  The  skull  (figs.  238,  239)  is  uncrusht,  but  the  hinder 
portion  of  the  base  is  damaged.  The  total  length  from  the  snout  to  the  end  of  the  supraoc- 
cipital  spine  is  205  mm.;  the  width  thru  the  quadrates  is  145  mm.  The  skull  is  remarkable 
for  the  length  of  the  posterior  lateral,  or  squamosal,  processes.  These  lack  but  little  of  extend- 
ing backward  as  far  as  the  supraoccipital  process;  while  the  latter  has  about  its  usual  length. 
The  parietals  are  unusually  narrow.  Williston  informs  us  that  these  bones  join  the  squamosals. 
The  frontals  and  the  prefrontals  together  occupy  the  area  occupied  in  Chelonia  mydns  by  the 
frontals.  In  front  of  the  prefrontals  come  the  large  nasals,  bones  rarely  found  in  Cryptodira. 
These  nasals  are  about  13  mm.  long  and  each  is  about  19  mm.  wide.    The  antero-posterior 


Figs.  240-243. — Desmatochelys  lowi.     Portions  of  the  type.      Xj. 


240.  Humerus. 

241.  Pelvic  bones.    //,  ilium;   ijc/t,  ischium;   puhj  pubis. 


242.  Fragments  of  peripheral  bones. 

243.  Fragments  of  plastron  and  peripheral  bones. 


diameter  of  the  nasal  opening  is  24  mm.;  the  transverse  diameter,  18  mm.  It  looks  strongly 
upward.  The  orbits  have  an  antero-posterior  diameter  of  60  mm.  The  interorbital  space  is 
58  mm.  wide. 

The  palate  (fig.  239)  is  remarkable  on  several  accounts.  The  choanae  are  considerably 
further  forward  than  they  are  in  the  Cheloniidae;  but  what  is  more  important,  there  is  no  floor 
beneath  them  formed  by  the  bones  bounding  them.  Each  is  at  the  anterior  end  of  a  longitudinal 
concavity,  whose  depth  diminishes  backward.  The  transverse  sutures  between  the  palatmes 
and  the  pterygoids  are  relatively  much  further  backward  than  they  are  in  Chelonia  mydas. 
The  pterygoid  processes  are  therefore  more  posterior  than  usual.  The  possession  of  posterior 
palatine  foramina  is  another  feature  distinguishing  this  species  from  any  of  the  modern  sea- 
turtles.  They  are  small,  and  may  be  regarded  as  vestigial.  Behind  the  pterygoid  processes 
the  palate  narrows  to  a  width  of  about  22  mm.  In  front  of  the  processes  named  there  is  another 
slight  constriction  of  the  palate.  The  longitudinal  median  sutures  are  not  discernible,  and  it 
is  not  certain  that  the  palatines  joined  in  the  midline. 


DESMATOCHELYID^.  iS/ 

The  lower  jaw  is  firmly  cemented  to  the  skull,  hence  no  examination  can  be  made  of  the 
triturating  surfaces;  they  were,  however,  undoubtedly  narrow.    The  symphysis  is  43  mm.  long. 

Williston  has  described  and  figured  one  cervical  vertebra.  It  is  26  mm.  long,  a  fact  indi- 
cating that  the  neck  was  short.  The  articular  surface  is  26  mm.  from  side  to  side  and  15  mm. 
vertically.    Near  the  hinder  end  of  the  centrum  there  is,  on  each  side,  a  stout  transverse  process. 

The  sacral  and  several  caudal  vertebrx  are  preserved  and  have  been  described  by  Williston. 
The  caudals  are  all  small  and  procoelous. 

The  length  of  the  scapula,  measured  from  the  tip  to  the  lower  border  of  the  proscapular 
process,  is  158  mm.  The  process  just  named  is  82  mm.  long.  The  coracoid  has  a  length  of 
100  mm.  and  a  width,  at  the  free  end,  of  35  mm.  The  shaft  is  much  constricted  in  the  middle 
of  the  length. 

The  humerus  (fig.  240)  is  a  large  flat  bone,  which,  by  its  whole  structure,  shows  that  it 
belonged  to  a  turtle  which  dared  the  open  seas.  The  length,  from  the  proximal  surface  of  the 
head  to  the  distal  end,  is  202  mm.;  while  the  extreme  length  is  260  mm.  The  last  dimension 
indicates  the  great  height  of  the  ulnar  process.  The  width  across  the  head  and  the  ulnar 
process  is  about  1 10  mm.  The  shaft,  where  narrowest,  has  a  diameter  of  80  mm.  The  distal 
end  is  rounded  and  has  a  width  of  80  mm.  The  radial  process  is  large  and  extends  downward 
on  the  shaft  about  90  mm.  below  the  upper  surface  of  the  head. 

Williston  figures  a  radius,  a  supposed  ulna,  and  various  bones  belonging  to  the  hand. 
Fig.  241,  from  Williston,  represents  the  ilium,  ischium,  and  pubis  of  the  right  side.  Williston 
figures  also  an  incomplete  femur.    Evidently  it  was  a  feebler  bone  than  the  humerus. 

But  littleof  the  carapace  was  secured.  The  costal  plates  have  a  thickness  of  only  2  or  3  mm. 
The  rib-heads  are  stout.  One  of  the  hinder  costals  has  a  width,  near  the  proximal  end,  of 
40  mm.  The  neural  corresponding  to  it  is  32  mm.  wide.  No  sulci  have  been  observed  on  any 
of  the  bones  of  the  carapace. 

Fig.  242,  from  Williston,  represents  the  pygal  and  the  adjoining  right  peripheral.  The 
pygal  measures  antero-posteriorly  at  the  midline,  61  mm.;  and  from  side  to  side,  97  mm. 
Its  thickness  is  6  mm. 

Fig.  243  represents  a  fragment  of  one  of  the  plastral  bones  and  one  of  the  lateral  peripherals. 
Evidently,  the  plastral  bones  were  loosely  connected  with  the  carapace,  as  in  the  Cheloniidae. 
The  peripheral  has  a  length  of  130  mm.,  and  a  width  of  about  35  mm.,  and  a  thickness  of  6  mm. 
Other  peripherals,  believed  to  be  more  anterior  in  position,  are  thicker  and  longer. 

Not  enough  of  the  plastron  was  secured  to  furnish  exact  knowledge  regarding  its  structure. 

Genus  NEPTUNOCHELYS  Wieland. 

A  genus  based  wholly  on  a  humerus  of  a  turtle  which  was  adapted  for  life  on  the  sea. 
Humerus  flattened;  the  head,  the  ulnar,  and  the  radial  processes  in  the  plane  of  flattening,  or 
nearly  so.  Radial  process  not  so  far  removed  from  the  head  as  in  the  Protostegidae.  Humerus 
resembling  that  of  the  Cheloniidae,  still  more  that  of  Desmatochelys,  differing  from  the  latter 
in  having  the  head  more  nearly  in  the  axis  of  the  bone  and  the  ulnar  process  nearly  parallel 
with  the  axis. 

Type:    Neptunochelys  tuberosa  (Cope). 

Neptunochelys  tuberosa  (Cope). 

Fig.  244. 

?Holcodus  acutidens,  Leidy,  Smithson.  Contrib.  Knowl.,  xiv,  art.  vi,  1865,  pp.  42,  118,  plate  viii,  figs.  I,  2. 
Protostega  tuberosa,  CoPE,  Fifth  Ann.  Report  U.S.  Geol.  Surv.,  Montana,  etc.,  1871  (1872),  p. 334;  Vert. 

Cret.  Form.  West,  1875,  p.  257. 
Atlantochelys  tuberosus,  Leidy,  Ext.  Vert.  Fauna  West.  Terrs.,  1872,  p.  342. 
Neptunochelys  tuberosa,  Wieland,  Amer.  Jour.   Sci.  (4),  IX,  1900,  pp.  417,  418. — Hay,  Bibliog.   and 

Cat.  Foss.  Vert.  N.  A.,  1902,  p.  440. 

No  part  of  this  great  sea-turtle  is  known  except  the  humerus.  This  was  found  many 
years  ago  by  Dr.  Spillman,  in  Upper  Cretaceous  deposits,  at  Columbus,  Mississippi.  Having 
been  found  associated  with  the  bones  of  a  mosasauroid  reptile  and  described  before  the  limbs  of 
the  Mosasauria  were  known,  it  was  believed  to  be  possibly  the  humerus  of  HolcoJus  acutidens. 


i88 


FOSSIL    TURTLES    OF    NORTH    AMKRICA. 


Cope  was  the  first  to  refer  the  hone  to  the  turtles,  and  he  placed  it  in  his  genus  Protostega. 
At  a  little  later  time  Leidy  referred  it  to  Atlantochelys.  In  1889  Baur  correctly  concluded 
that  it  could  belong  to  neither  Protostega  nor  to  Atlantochelys,  but  he  did  not  name  the  genus. 
This  was  reserved  for  Wieland  to  do  in  1900. 

The  total  length  of  the  humerus  (fig.  244)  is  10  inches,  or  253  mm.  The  shaft,  where 
narrowest,  is  48  mm.  wide  and  28  mm.  thick.  The  distance  from  the  extremity  ot  the  ulnar 
process  to  that  of  the  radial  process  was  estimated  to  be  152  mm.  The  breadth  ot  the  distal 
end  is  93  mm.;  the  thickness,  30  mm.  The  form  of  the  bone  is  shown  by  the  figure,  copied 
from  Leidy. 

Genus  ATLANTOCHELYS  Agassiz. 

A  genus  based  on  the  proximal  end  of  a  humerus  of  a  sea-turtle.  The  head  and  the  ulnar 
and  radial  processes  in  approximately  the  same  plane.  Radial  process  hardly  separated  from 
the  head.     Ulnar  process  directed  nearly  parallel  with  axis  of  bone.     Shaft  unusually  slender. 

Type:  Atlantochelys  mortem  Agassiz. 


Fig.     244. — Neptunochelys    tuherosa. 
Humerus  forming  the  type.    Xj. 


Fig, 


245. — Atlantochelys  mortoni.   Portion  of  humerus 
forming  the  type.      X  §  ± .  After  Leidy. 


Atlantochelys  mortoni  Agassiz. 
Fig.  245. 

Atlantochelys  mortoni,  Agassiz,  Proc.  Acad.  Nat.  Sci.  Phila.  1849,  p.  169  (no  description);  in  Leidy, 
Smithson.  Contrib.  Knowl.,  xiv,  art.  vi,  1865,  p.  43. — Leidy,  Ext.  Vert.  Fauna  West.  Terrs., 
1872,  p.  342. — Wieland,  Amer.  Jour.  Sci.  (4),  1900,  p.  419,  figs.  14-16. — Hay,  Amer.  Naturalist, 
XXXII,  1898,  p.  930;   Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  440. 

Mosasaurus  mitchelli,  Leidy,  Smithson.  Contrib.  Knowl.,  xiv,  art.  vi,  1865,  43,  117,  plate  viii,  figs.  3-5. 

Protostega  neptunia.  Cope,  Fifth  Ann.  Report  U.  S.  Geol.  Surv.  Terrs.,  1871  (1872),  p.  334;  Proc.  Amer. 
Philos.  Soc,  XII,  1872,  p.  433;   Vert.  Cret.  Form.  West,  1875,  p.  257. 

Like  Neptunochelys  tuherosa,  this  species  is  based  on  a  humerus  which  was  derived  from 
the  Upper  Cretaceous  formation.  The  exact  locality  and  level  were  not  reported,  but  we 
know  that  the  fossil  was  found  in  one  of  the  beds  of  Cretaceous  greensand  in  Burlington 
County,  New  Jersey. 

Of  this  humerus  (fig.  245)  there  was  secured  only  the  proximal  half  or  less.  This  fragment 
had  a  length  of  about  280  mm.  The  shaft  was  extremely  slender,  being  73  mm.  wide  and 
60  mm.  thick.    The  ulnar  process  rises  above  the  head  about  75  mm.    The  radial  process  is 


DESMATOCHELYID^. 


189 


hardly  separated  from  the  head.  The  ulnar  process  is  nearly  parallel  with  the  long  axis  of  the 
bone.  The  head  is  farther  removed  from  the  axis  than  in  Neptunochelys.  In  these  two 
respects  Atlantochelys  resembles  Desmatochelys;  but  it  differs  from  the  latter  in  having  a 
slender  shaft.  This  humerus  must  have  been  fully  as  long  as  that  of  Archelon,  but  it  was  of 
very  different  form.    A  very  large  turtle  is  indicated. 

Family  PROTOSTEGIDiE  Cope. 

Marine  turtles  with  the  fore  limbs  converted  into  flippers  resembling  those  of  the  Che- 
loniidae.  Carapace  greatly  reduced,  the  disk  extending  not  one-half  the  distance  toward  the 
distal  ends  of  the  ribs.  Peripherals  present.  Plastron  loosely  connected  with  the  carapace 
and  with  a  large  median  fontanel.  Entoplastron  T-shaped,  with  the  lateral  wings  elongated 
and  distally  expanded.  Epiplastra  not  certainly  known.  Xiphiplastra  short  and  bent.  Skull 
large,  temporal  region  broadly  rooft  over.  Region  in  front  of  the  orbits  elongated.  Jaws  with 
large  crushing-surfaces.     Choanae  far  forward;  not  underfloored  by  the  surrounding  bones. 

Genera:    Protostega,  Archelon,  and  probably  Protosphargis,  all  of  the  Upper  Cretaceous. 

The  writer  is  strongly  of  the  opinion  that  the  genera  Protostega  and  Archelon  ought  to  be 
kept  apart  from  the  modern  sea-turtles  as  a  distinct  family.     That  both  the  Protostegidae 


Fig.  246. — Protostegfi  potens.     Entoplastron  and  xiphiplastron  of  type.     X  i. 
ent,  entoplastron;    xiph,  xiphiplastron. 

and  the  Cheloniidae  had  their  origin  from  a  common  ancestor,  which  was  a  sea-going  turtle, 
need  not  be  denied;  but  the  two  branches  have  been  separated  so  long,  and  each  has  developt 
so  many  peculiarities,  that  it  seems  unwise  to  force  them  into  the  same  family.  That  the 
Cheloniidae  have  been  derived  directly  from  the  Protostegidae  it  is  impossible  to  believe.  The 
latter  family  was  in  several  respects  more  highly  differentiated  than  the  living  sea-turtles. 
The  greatly  reduced  carapace,  the  peculiar  entoplastron,  the  abbreviated  xiphiplastra,  the 
large  preorbital  region,  and  the  strongly  modified  humeri  are  examples  of  these  differentiations. 

For  the  discussion  of  the  relationships  of  this  family  to  the  Cheloniidae  and  to  the  Der- 
mochelyidse,  the  reader  is  referred  to  the  papers  of  Baur,  Case,  Fiirbringer,  Van  Bemmelen, 
Boulenger,  Lydekker,  Dollo,  Wieland,  and  Hay. 

The  bone  which  is  here  regarded  as  the  entoplastron  (fig.  246,  ent)  was,  in  Protostega, 
originally  described  by  the  present  writer,  on  the  advice  of  Dr.  Baur,  as  the  nuchal.  This 
view  was  adopted  by  Case  and  afterwards  by  Wieland.*  The  latter,  in  describing  Archelon, 
originally  held  the  bone  to  be  the  coalesct  epiplastra  and  entoplastron,  called  by  him  the 
paraplastron.  A  re-examination  of  the  subject,  in  the  light  of  all  the  known  materials,  has 
led  the  present  writer  to  change  his  opinion.  The  reasons  for  regarding  this  bone  as  the 
entoplastron  are  the  following: 

(i)  The  bone  has  never  been  found  in  direct  connection  with  peripheral  bones. 

(2)  It  has  been  found  four  times  closely  associated  with  plastral  bones,  and  in  two  or 
three  of  these  cases  it  was  in  its  apparently  natural  position  with  relation  to  the  hyoplastra. 

♦Since  this  was  sent  to  the  press  Dr.  Wieland  has  publisht  a  paper  (Ann.  Carnegie  Mus.,  iv,  1906, 
p.  8)  in  which  he  accepts  the  view  that  the  bone  is  the  entoplastron. 


lyO  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

In  the  first  instance  it  accompanied  only  plastral  bones  that  were  described  by  the  writer. 
Then  Case  found  it  with  its  lateral  wings  resting  on  the  hyoplastra.  He  supposed  that  it 
had  fallen  from  the  carapace  to  its  position,  a  not  unreasonable  conclusion.  After  this 
Wieland  informed  us  that  he  had  found  it  twice  in  place,  resting  directly  upon  the  anterior 
portions  of  the  hyoplastra  and  beneath  numerous  other  skeletal  parts. 

(3)  Wieland  described  a  bone  as  the  nuchal  which  can  hardly  be  anything  else. 

(4)  In  the  specimen  described  here  as  P.  potens  the  bone  in  question  again  occurs.  On 
the  visceral  surface,  near  the  anterior  border,  there  is,  on  each  side,  a  deep  and  broad  groove 
(fig.  246)  that  must  have  received  another  bone.  This  groove  reaches  nearly  to  the  midline. 
It  is  quite  improbable  that  the  first  peripheral  had  a  long  process  that  filled  this  groove.  On 
the  other  hand,  the  epiplastron  might  be  expected  to  lie  on  the  upper  side  of  the  entoplastron. 
The  structure  of  this  entoplastron  is  not  far  distant  from  that  of  Chelydra.  In  this  genus 
there  is  a  median  backwardly  directed  process  from  the  anterior  end  of  which,  on  each  side, 
there  projects  a  lateral  slender  process.  Were  these  lateral  processes  to  become  directed 
at  right  angles  with  the  median  process  and  to  become  broader,  we  would  have  just  such  an 
entoplastron  as  we  have  in  Protostega.  In  Chelydra,  Chelonia,  and  Caretia  we  find  that 
the  epiplastra  overlap  the  lateral  processes  of  the  entoplastron,  just  as  they  seem  to  have 
done  in  Archelon  and  Protostega. 

As  regards  the  superposition  of  the  T-shaped  bone  on  the  hyoplastra  of  Protostega  there  is 
this  to  be  said.  The  entoplastron  appears  naturally  to  join  the  hyoplastra  edge  to  edge.  Often, 
perhaps  usually,  the  hyoplastra  push  themselves  slightly  over  the  entoplastron  anteriorly. 
It  is,  however,  certain  that  the  posterior  spine-like  prolongation  falls  above  the  hyoplastra. 
If  the  entoplastron  expanded  laterally  without  suturally  joining  the  hyoplastra,  there  appears 
to  be  no  reason  why  it  should  not  rather  pass  above  than  below  the  latter  bones.  The  epiplastra 
are  missing  in  all  the  specimens  in  which  the  T-shaped  bone  accompanies  plastral  bones. 
These  were,  however,  probably  thin,  light  bones  and  could  easily  be  removed  from  their 
natural  position.  Their  outer  ends,  doubtless,  were  in  ligamentous  union  with  the  anterior 
borders  of  the  hyoplastra. 

In  Wieland's  paper  just  referred  to  he  describes  a  bone  of  Archelon  which  he  regards 
as  the  left  epiplastron.  He  holds  that  this  bone  was  overlapt  by  the  outer  end  of  the  T- 
shaped  entoplastron,  that  certain  grooves  in  the  bone  were  filled  by  digitations  or  ridges  of 
the  entoplastron,  and  that  the  thickened  anterior  end  of  the  bone  projected  outward  and 
forward  as  in  the  trionychids.  The  present  writer  finds  it  impossible  to  place  the  bone  in 
this  position.  It  seems  more  probable  that  the  bone  is  the  right  epiplastron,  that  the  thinner 
end  narrowed  to  a  point  and  was  directed  inward  on  the  upper  surface  of  the  wing  of  the 
entoplastron,  while  the  thickened  end  was  directed  backward  along  the  border  of  the  hyo- 
plastron. 

Genus  PROTOSTEGA  Cope. 

Premaxillary  beak  less  developt  than  in  Archelon.  Maxilla  with  a  rather  broad  grinding- 
surface,  which  extends  backward  to  behind  front  of  orbit.  Lower  jaw  with  the  rami  early 
co-ossified.  Entoplastron  T-shaped,  with  the  middle  third  of  the  anterior  border  concave 
from  side  to  side,  the  distal  ends  convex.     Radial  process  of  humerus  large. 

Type:  Protostega  gigas  Cope. 

Protostega  gigas  Cope. 

Figs.  247-253. 

Protostega  gigas,  CoPE,  Proc.  Amer.  Philos.  See,  Xll,  1871,  pp.  175,  452;  Fifth  Ann.  Report  U.S.  Geo!. 

Surv.  Montana,  etc.,  1871  (1872),  pp.  323,  335;   Vert.  Cret.  Form.  West,  1875,  pp.  48,  102,  256, 

plate  ix,  figs.  1-7;   plates  x-xiii;  Amer.  Naturalist,  xil,  1878,  p.  137.- — Hay,  Pubs.  Field  Columb. 

Mus.,  Zool.,  1, 1895,  p.  57,  plate  iv,  v;  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  440. — Case,  Jour. 

Morphology,  xiv,  1897,  p.  21,  plates  v-vi. — Wieland,  Amer.  Jour.  Sci.  (4),  ix,  1900,  pp.  416,  420, 

figs.  8,  19;  Mem.  Carnegie  Mus.,  11,  1906,  p.  279,  plates  xxxi-xxxiii,  text-fig.  I. — WlLLISTON,  Amer. 

Jour.  Sci.  (4),  XIII,  1902,  p.  276,  fig.  I. — OsBORN,  Science,  xix,  1904,  p.  35. — Sternberg,  Trans. 

Kansas  Acad.  Sci.,  xix,  1905,  p.  123. 
Atlantochelys  gigas,  Dana,  Manual  Geol.,  ed.  11,  1875,  p.  466. 


PROTOSTEGID^. 


191 


The  specimen  of  this  species  which  Cope  originally  described  was  found  by  him  in  1871, 
in  Niobrara  deposits,  near  Butte  Creek,  south  of  Wallace,  Kansas.  This  is  now  in  the  Ameri- 
can Museum  of  Natural  History  and  has  the  number  1503.  At  the  time  of  its  discovery  the 
bones  were  much  distorted  and  comprest;  and  most  of  them  were  much  fractured  in  collecting 
them.  Cope  states  that  the  portions  described  by  him  were  reconstructed  out  of  over  800 
pieces.  One  of  the  large  bony  plates,  described  as  overlying  the  ribs,  had  been  broken  into 
108  pieces.  Most  of  the  bones  are  yet  in  the  condition  in  which  Cope  left  them;  the  large 
plates  are,  to  a  great  extent,  again  broken  up. 

As  stated  by  Cope,  the  remains  preserved  include  many  parts  of  the  skull;  5  vertebrx, 
more  or  less  incomplete;  the  scapular  arches  of  both  sides,  with  the  coracoids;  both  humeri 
perfect,  and  some  phalanges;  10  ribs;  i  doubtful  neural  bone;  10  peripherals;  parts  of  4 
large  plates,  described  as  overlying  the  ribs;  and  some  undetermined  bones. 

From  his  study  of  his  materials  Cope  arrived  at  the  conclusion  that  Protostega  was  a 
large  marine-turtle  closely  allied  to  Dermochelys,  and  had  a  total  length  of  about  12  feet. 

The  first  author  who  added  to  the  knowledge  of  the  species  was  Dr.  George  Baur,  who 
(Zool.  Anzeiger,  ix,  1886,  p.  688),  regarding  the  genus  as  Atlantochelys,  stated  that  the  plates 
assigned  by  Cope  to  the  dorsal  region  were  really  portions  of  the  plastron.  This  determination 
was  undoubtedly  made  from  the  bones  collected  by  Cope.    Hay,  as  cited,  gave,  in  1897,  a 


Fig.  247. — Protostega  gigas.     Skull  of  type 


Cope's  determinations  of  the  bones  within  parentheses,  ju  (pt),  jugal,  Cope's  pterygoid  ;  m.v  (por),  inaiilla, 
called  by  Cope  the  postorbital;  prf,  prefrontal;  pof,  postfrontal;  quj  (col),  quadratojugal,  Cope's  columella; 
sj  (mx),  squamosal,  called  by  Cope  maxilla. 

description,  with  figures,  of  the  hyoplastra  and  hypoplastra  of  a  specimen  that  had  been 
collected  for  him  near  Butte  Creek,  Kansas.  Case  (1897,  as  cited)  described  portions  of  the 
skull  and  a  more  complete  plastron  than  had  previously  been  secured,  materials  now  in  the 
University  of  Kansas;  and  made  correction  of  Hay's  restoration  of  the  xiphiplastra.  More 
recently  Wieland  has  described  excellent  materials  which  belong  to  the  Carnegie  Museum, 
at  Pittsburg. 

Cope  had  considerable  portions  of  the  skull  and  most  of  these  he  figured.  The  writer 
has  studied  these  bones  and  has  found  that  in  most  cases  Cope's  determinations  were  incorrect. 
Baur  had  also  examined  these  cranial  bones  and  accepted  Cope's  determinations  (Amer. 
Naturalist,  xxiv,  1890,  p.  532). 

Fig.  247  represents  these  bones,  each  having  its  name  indicated.  Cope's  determinations 
are  indicated  in  parentheses. 

The  first  of  these  elements  that  will  be  noticed  is  that  which  Cope  called  the  postfrontal 
(Vert.  Cret.  Form.  West,  plate  xi,  figs.  30,  3*).  In  his  description  he  called  this  the  left  post- 
frontal; but,  since  the  straight  margin  was  regarded  as  the  lower,  the  bone  would  have  to  be 
placed  on  the  right  side.  In  reality,  the  bone  is  the  left  maxilla  (fig.  247,  mx),  joined  to  the 
prefrontal.  The  straight  border  is  the  cutting-border  of  the  maxilla;  and  the  crusht  tritu- 
rating surface  is  seen,  in  Cope's  figure,  pushed  below  this  border.     Evidently  the  cuttmg- 


192 


FOSSIL    TURTLES    OP"    NORTH    AMERICA. 


edge  did  not  extend  much  below  the  triturating  surface  during  Hfe.  We  can  not  now  tell 
how  wide  the  triturating  surface  was  originally.  At  its  anterior  end  is  seen  a  broad  articular 
surface  for  the  vomer.  Cope  thought  that  this  surface  was  for  the  "zygomatic"  bone.  Cope 
did  not  recognize  the  suture  between  the  lower  and  the  upper  portions  of  the  mass  of  bone 
figured  by  him.  The  suture  is  not  distinct,  but  the  radiations  on  the  surfaces  of  the  bones 
show  distinctly  where  the  suture  is  located.  The  upper  bone  is  the  prefrontal,  prf.  On  the 
inner  side  of  its  upper  border  is  a  broad  articular  surface  for  union  partly  with  its  fellow  bone, 
partly  with  the  frontal.  Posteriorly  the  prefrontal  articulated  with  the  postfrontal,  pof,  thus 
excluding  the  frontal  from  the  orbit.  In  Cope's  fig.  ^a  is  seen  a  bridge  of  bone  joining  the 
prefrontal  with  the  maxilla.  The  upper  part  of  this  bridge  is  undoubtedly  the  descending 
plate  of  the  prefrontal  which  joined  the  vomer;  the  lower  portion  of  the  bridge  is  quite  certainly 
a  portion  of  the  palatine.  The  foramen  between  the  bridge  and  the  maxilla  is  the  nasopalatine. 
Cope  did  not  explain  the  presence  of  such  a  bridge  of  bone  on  the  supposed  postfrontal. 

The  bones  described  by  Cope  as  the  pterygoid  and  the  columellar,  and  accepted  as  such 
by  Baur,  are  the  jugal,  ju,  and  the  quadratojugal,  quj.  Those  of  the  right  side  are  shown  in 
Cope's  fig.  5,  plate  x;  those  of  the  left  side  in  his  fig.  i,  plate  xi.  What  Cope  regarded  as  the 
posterior  end  of  the  larger  bone  is  the  anterior.  The  more  concave  border  formed  a  part  of 
the  rim  of  the  orbit.  The  form  of  both  these  bones  is  almost  exactly  as  in  Archelon  ischyros, 
as  figured  by  Wieland.  As  in  that  species,  the  jugal  extended  backward  to  the  quadrate. 
The  hinder  border  of  the  quadratojugal  is  concave  to  form  the  anterior  boundary  of  the 
tympanic  cavity.  '  It  is  to  be  noted  that  the  conspicuous  oval  mark  shown  in  Cope's  fig.  i, 
plate  xi,  is  nothing  but  a  little  matrix  overlaid  by  a  thin  layer  of  bone,  probably  of  some  fish. 
In  Cope's  fig.  5,  plate  x,  the  quadratojugal  is  in  nearly  its  natural  position.  It  is  there  recog- 
nized as  the  zygomatic  (quadratojugal),  but  it  is  the  fellow  of  the  bone  which  on  the  other 
side  is  determined  as  the  pterygoid.  The  other  bone,  the  jugal,  has  been  turned  end  about, 
to  agree  with  Cope's  idea  of  its  proper  position. 

Both  quadrate  bones  are  present;  and  that  of  the  right  side  is  represented  in  Cope's 
fig.  5,  plate  X.  Both  are  badly  crusht,  but  that  of  the  right  side  shows  the  condyle  less  distorted. 
Just  above  the  condyle,  on  the  outside  of  the  bone,  is  a  scar  where  the  quadratojugal  articu- 
lated with  the  quadrate.  On  the  inner  border  of  the  latter  bone  is  another  articular  surface  for 
the  hinder  end  of  the  pterygoid. 

Cope's  fig.  2,  plate  xi,  represents  a  bone  which  he  identifies  doubtfully  with  the  anterior  end 
ot  the  pterygoid.  It  is  really  nearly  the  whole  of  the  pterygoid,  a  small  portion  of  the  anterior 
end  alone  being  broken  away.  Cope's  figure  represents  the  bone  as  seen  from  below.  At  the 
hinder  end  of  the  bone,  on  its  upper  surface,  is  a  large  rough  surface  for  articulation  with  the 
quadrate.  From  this  extends  forward  a  ridge  which  may  have  joined  anteriorly  either  the 
columellar  bone  of  the  lower  end  or  the  descending  process  of  the  parietal.  At  the  hinder  end 
and  below,  and  represented  in  Cope's  figure,  is  a  rough  excavation  for  the  border  of  the  basioc- 
cipital.  The  mesial  half  of  the  middle  third  of  the  lower  surface  is  occupied  by  a  rough  surface 
which  was  overlapt  by  the  basisphenoid.  The  relations  here  appear  to  have  been  much  as  in 
Dermochelys.    The  pterygoids  are  relatively  narrow,  outer  borders  thickened  and  obtuse. 

The  bone  identified  by  Cope  as  the  maxilla  (fig.  247,  sq)  is  the  squamosal.  Cope  represents 
that  of  the  left  side.  He  regarded  the  curved  border  above  the  elongated  process  as  the  border 
of  the  orbit  and  states  that  the  width  of  the  bone  below  the  orbit  was  35  mm.  Fortunately,  the 
corresponding  bone  of  the  other  side  is  present;  and  this  shows  that  that  curved  border  is  the 
result  of  damage  to  the  bone.  The  upper  edge  of  the  bone  should  extend  above  the  lower 
border  at  least  90  mm.  What  Cope  took  to  be  the  cutting-edge  of  the  maxilla  is  the  free, 
sharp,  and  smooth  hinder  border  of  the  squamosal,  ascending  toward  the  parietal.  What 
Cope  regards  as  the  premaxillary  border  is  a  free  border  descending  to  the  quadrate.  The  wing 
of  bone  seen  extending  upward  in  Cope's  figures  is  the  horizontal  plate  of  the  squamosal  which 
overlapt  the  upper  end  of  the  quadrate  and  the  outer  end  of  the  paroccipital.  Pressure  has 
caused  it  to  lie  nearly  parallel  with  the  body  of  the  bone.  On  the  outer  border,  that  opposite 
the  long,  straight  border,  is  seen  a  portion  of  the  tympanic  cavity.  Wieland's  figure  of  the  skull 
of  this  species  shows  that  a  process  of  the  squamosal  reaches  the  outer  border  of  the  parietal. 

The  true  postfrontal  bone  (fig.  247,  pof)  is  present,  but  it  was  not  figured  by  Cope  and 
appears  not  to  have  been  mentioned.     It  has  on  its  lower  border  a  process  which  articulates 


protostegidj*:. 


193 


with  the  upper  border  of  the  jugal.  The  hinder  end  of  the  bone  is  broken  away,  so  that  the 
whole  length  can  not  be  determined.  The  breadth  of  the  bone,  taken  just  behind  the  process 
mentioned,  is  105  mm. 

No  other  parts  of  the  palatines  appear  to  have  been  preserved  than  that  already  mentioned. 
No  parts  of  the  premaxillae,  nor  vomer,  nor  parietals,  nor  supraoccipital  appear  to  have  been 
obtained  with  the  bones  above  described. 

Portions  of  the  skull  of  this  species  were  described  by  Case  as  cited  in  the  synonymy. 
The  supraoccipital  is  stated  to  resemble  closely  that  of  the  Cheloniidae,  and  to  be  quite  different 
from  that  of  Dermochelys.  The  basioccipital  resembles  that  of  the  latter  species,  except  that 
the  portion  belonging  in  the  condyle  is  well  ossified.  The  basisphenoid  is  said  to  resemble  that 
oi  Dermochelys,  but  is  not  so  large.  Case  pointed  out  that  the  hinder  end  of  the  pterygoid  was, 
as  in  Dermochelys,  separated  from  the  exoccipital  by  a  lateral  process  of  the  basioccipital.  The 
imperfectly  preserved  palatines  indicated  that  the  choanae  were  placed  far  forward.  The  vomer 
had  no  descending  process  to  assist  in  underflooring  the  nasal  passages.  The  quadratojugal 
and  the  squamosal  were  found  to  be  as  in  the  Cope_specimen,  but  to  the  present  writer  it 

pmxTL — ^ — r~^    mx,         ......  /!^  TQd 


Fig.  248. — Proiostega  gigas.     Skull,  limb  bones,  and  front  of  carapace.     Xi. 
No.  1421  Carnegie  Museum,  Pittsburg. 

Skull,    /r,  frontal;  y'u,  jugal;    mj:,  maiilla  ;   nor,  nares ;   ori,  border  of  orbit ;   ;ia,  parietal ;   />r/,  prefrontal ;   pmx, 

premaiilla;    pof,  postfrontal;  ?a,  quadrate;  qj,  quadratojugal;   sq,  squamosal. 
Lower  jaw.    ang,  angular;  dart,  dermarticular,  or  prearticular;    den,  dentary;   hy,  hyoid;   jar,  supraangular. 
Carapace,    nu.p,  part  of  nuchal;  per.  i,  per.  2,  first  and  second  peripherals;  r.  i,  second  rib. 
Fore  limb,    c,  centrale;    hum,  humerus;   rod,  radius ;    ul,  ulna  ;    ralf,  radiale  ? ;    i,  intermedium ;  uln,  ulnare ;  pi, 

pisiforme;    1-5,  carpals  of  second  row;   I-V,  metacarpals. 

appears  that  Case  has  mistaken  the  upper  border  of  the  quadratojugal  for  the  lower.  The 
mandible  was  in  perfect  condition.  The  symphysis  is  represented  as  being  equal  to  a  very  little 
more  than  one-third  the  whole  length  of  a  ramus.  In  addition  to_the  bones  found  in  the  lower 
jaw  of  ordinary  turtles  Case  states  that  the  bone  called  by  Baur^he  presplenial,  by  Williston 
the  true  splenial,  is  present. 

The  bones  described  and  figured  by  Cope  as  metapodials  (Cope's  plate  xu,  figs.  3,  4)  are 
certainly  not  such,  but  epipodials.  The  original  of  his  fig.  3  appears  to  be  a  tibia.  The  bone 
on  the  right  of  his  fig.  4  may  be  a  radius.  The  same  bone  in  Archelon,  as  Wieland  mforms 
the  writer,  is  now  regarded  by  him  as  the  ulna. 

No.  1421  of  the  Carnegie  Museum,  Pittsburg,  was  secured  in  the  Niobrara  Cretaceous, 
near  Hackberry  Creek,  Gove  County,  Kansas.  It  furnishes  the  nearly  complete  skull;  the 
humerus,  radius,  ulna,  most  of  the  carpal  bones,  and  some  phalanges  of  the  right  flipper;  and 
the  nuchal  and  first  three  right  peripherals.  These  bones  are  yet  imbedded  in  the  matrix,  so 
that  only  their  upper  surfaces  are  visible.  The  remains  have  been  studied  and  described  by 
Wieland,  whose  figure  is  here  reproduced  (fig.  248).  The  following  measurements  of  the  skull 
are  taken  from  his  paper: 


1^4  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

Millimeters. 

Extreme  length  of  ramus  of  lower  jaw 370 

Extreme  length  of  symphysis  of  lower  jaw 160 

Length  of  skull  from  beak  to  end  of  supraoccipital  spine 580 

Median  length  of  narial  opening 75 

Width  of  narial  opening 55 

Antero-posterior  length  of  orbit 120 

It  will  be  observed  that  this  skull  was  nearly  2  feet  in  length.  In  Wieland's  figure  the 
suture  between  the  parietals  was  omitted;  but  this  is  here  supplied. 

It  is  unfortunate  that  only  a  portion  of  the  nuchal  was  preserved.  Its  presence  would  have 
settled  the  question  regarding  the  identity  of  the  T-shaped  bone,  which  has  been  regarded  as 
the  nuchal.  The  portion  of  the  nuchal  (fig.  248,  iiu.  p)  remaining  with  this  specimen  does  not, 
the  writer  believes,  particularly  favor  the  opinion  that  it  is  the  T-shaped  bone. 

No.  1393  of  the  Carnegie  Museum  was  obtained  at  Twin  Butte  Creek,  Logan  County, 
Kansas.     It  is  fragmentary,  but  presents  various  portions  of  the  plastron,  limbs,  and  skull. 


Fig.  249. — Protostega  gtgas.      X  I's.     Carapace  of  No.  1420  Carnegie  Museum. 

I— 10,  the  ribs  of  the  carapace;    5,  sacral  rib. 

Some  series  of  the  peripherals  show  that  there  was  a  sharp  free  border  along  each  side.  From 
this  a  plate  of  bone  from  50  to  70  mm.  wide  rose  over  the  distal  ends  of  the  ribs.  From  the 
same  border  another  plate,  from  25  mm.  to  30  mm.  wide,  past  horizontally  inward  below  the 
rib-ends.  The  hyoplastron  and  the  hypoplastron  taken  together  measure  about  400  mm.  in 
length.  The  greatest  thickness  of  the  hyoplastron  is  about  15  mm.  The  hypoplastron  is 
somewhat  thinner.  Both  xiphiplastra  are  present.  They  are  of  the  form  shown  in  Case's 
figure,  but  they  are  not  so  abruptly  bent. 

Little  is  known  regarding  the  vertebrae  of  this  species.  Cope  had  remains  of  5,  but  he  was 
unable  to  determine  where  they  belonged.  They  probably  appertained  to  the  tail.  Cope 
supposed  that  the  dorsal  vertebrae  possest  transverse  processes,  but  Wieland's  figure  shows 
this  conclusion  to  have  been  erroneous.  Wieland  stated  that  a  specimen  at  the  Carnegie 
Museum  furnisht  6  of  the  cervicals,  but  he  did  not  describe  them.  Case  describes  2  caudals. 
They  were  procoelous. 

The  carapace  of  this  species  is  of  great  interest,  and  has  been  studied  by  Cope,  Case,  and 
Wieland.    Cope  had  secured  portions  of  10  ribs  of  the  type  specimen.    He  recognized  clearly 


PROTOSTEGID^. 


195 


the  fact  that  the  costal  plates  were  greatly  reduced,  so  that  the  ribs  were  free  from  one  another 
to  near  their  proximal  ends.  He  supposed  that  he  had  found  evidences,  from  the  great  length 
of  the  costal  plates  from  the  origin  of  the  rib-heads  to  the  proximal  border,  that  there  were  no 
neural  bones,  and  that  the  rib-heads  were  attacht  to  transverse  processes.  He  was  undoubtedly 
wrong  in  both  conclusions.  Case  had  for  examination  only  fragments  of  the  ribs.  He  found 
that  the  neural  borders  of  the  costal  plates  were  digitated;  and  from  the  considerable  extension 
of  these  plates  toward  the  midline  from  the  origin  of  the  rib-head,  he  concluded  that  there  was 
no  room  for  neurals.  He  found  that  the  costal  plates  extended  along  the  ribs  for  about  a  third 
of  their  length.  Wieland  had  the  opportunity  to  study  a  carapace,  No.  1420  of  the  Carnegie 
Museum,  which  showed  a  nearly  complete  series  of  ribs.  Fig.  249,  reproduced  from  Wieland, 
shows  this  carapace  as  seen  from  below.  He  found  the  neurals  to  be  present,  but  of  papery 
thinness  and  much  crusht  down  on  the  neural  arches.  Contrary  to  what  is  found  in  most 
turtles,  the  first  rib  is  not  turned  backward  against  the  second.  It  is  relatively  short.  The 
other  ribs  are  about  35  mm.  wide  at  the  middle  of  their  length.    The  costal  plates,  forming  the 


Fig.  250. — Protostega  g'gas.     Plastron.     X  ,'5.     After  figure  by  Case. 

«nr,  entoplastron;    /i;yo,  hyoplastron  ;   A)ipo,  hypoplastron ;   jfipA,  xiphiplastron. 
On  the  left  is  a  number  of  peripherals. 

disk  of  the  carapace,  extend  not  more  than  one-third  the  length  of  the  ribs.  The  total  length 
of  the  ten  dorsal  centra  was  680  mm.  The  distance  between  the  distal  extremities  of  the 
ribs  of  the  fourth  pair  was  1060  mm. 

The  nuchal  bone  of  some  members  of  the  Protostegidae  has  already  been  discust.  Cope 
figured  a  bone  which  he  regarded  as  the  nuchal.  It  is  certainly  a  median  bone,  but  it  appears 
to  be  too  small  to  be  the  nuchal,  and  may  be  the  pygal.  The  nuchal  may  be  supposed  to 
resemble  that  oi  Archelon,  as  figured  by  Wieland  (Amer.  Jour.  Sci.,  v.,  1898,  p.  17). 

Of  the  peripherals  Cope  had  12,  but  the  exact  position  of  these  could  not  be  determined. 
They  were,  moreover,  greatly  flattened  by  the  pressure  to  which  they  had  been  subjected. 
Some  of  these  had  only  a  single  lamina,  that  rising  to  the  ribs.  Others  possest,  besides  this,  a 
lamina  that  projected  toward  the  bones  of  the  plastron.  The  end  of  a  rib  was  partly  buried  m 
the  lower  surface  of  the  upper  lamina  of  each.  The  external  border  of  each  peripheral  behmd 
the  second  was  acute.  The  upper  lamina  was  thin  and  its  upper  border  terminated  in  digita- 


196 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


tions.  We  are  indebted  to  Case  for  more  exact  knowledge  of  the  peripherals.  He  had  a  series 
of  8  of  these  in  their  natural  order  (fig.  250).  The  most  anterior  was  supposed  to  be  the  second. 
It  is  slender,  concave  along  its  free  border,  as  if  to  make  room  for  free  movements  of  the  limb, 
and  has  no  pit  for  a  rib.  It  is  170  mm.  long  and  only  30  mm.  wide.  The  third  is  strong,  broad, 
and  has  a  rib-pit.  Its  length  is  170  mm.  and  its  width  118  mm.  The  succeeding  ones  are  longer 
than  wide  and  have  2  laminae,  the  uppermost  of  which  is  the  broader.  All  these  peripherals 
are  closely  joined  together  by  means  of  coarse  sutures. 

^Wieland  figures  (Mem.  Carnegie  Mus.,  11,  p.  282)  a  portion  of  a  nuchal  bone  and  the  first 
and  second  peripherals.    The  figure  is  here  reproduced  (fig.  248). 

The  hyoplastra  and  the  hypoplastra  were  described  by  Cope  as  dermal  bones  that  were 
supposed  to  overlie  the  ribs.  Baur's  suggestion  that  these  bones  belonged  to  the  carapace  has 
been  mentioned.  They  had  been  comprest  until  the  greatest  thickness  was  only  about  15  mm. 
A  plastron  described  by  the  present  writer  showed  that  these  bones  were  really  thick  and  heavy, 
the  thickness  amounting  to  as  much  as  45  mm.  in  the  case  of  the  hyoplastron.  The  plastron 
described  by  Case  (fig.  250)  was  somewhat  larger  than  the  one  last  referred  to  and  furnisht 
representatives  of  all  the  elements  except  the  epiplastra.  The  hyoplastra  and  hypoplastra  are 
bones  of  an  irregularly  triangular  form,  with  all  the  borders  digitated,  except  over  the  fore  and 


met. 
phal. 


Fig.  251. — Protostega  gigas.     Right  shoulder-girdle  and  limb;    dorsal  view.     XA. 

c,  centrale;    cor,   coracoid;    hum,  humerus;   Int,  intermedium;   I-V,  the  digits;   met,  metacarpals;    phal,  first  row  of 
phalanges;  pi,  pisiforme;  pcor,  procoracoid  process;  rod,  radius;  ul,  ulna;  uln,  ulnare;  1-5,  carpals  of  second  row. 

hinder  limbs.  From  the  anterior  inner  angle  of  the  hyoplastron  a  thickening,  appearing  on  the 
lower  surface  as  a  low  ridge,  runs  backward  thru  the  articulation  with  the  hypoplastron  and 
on  backward  to  the  xiphiplastra.  From  this  ridge,  in  each  direction,  the  thickness  is  reduced 
until  the  borders  are  reacht.  Evidently  there  were  considerable  spaces  left  between  the  plastral 
bones  and  the  peripherals.  In  the  midline  there  was  a  great  fontanel,  which  extended  from 
the  entoplastron  to  the  xiphiplastra.  The  union  of  the  plastral  bones  with  the  peripherals  was 
a  ligamentous  one. 

As  stated,  the  entoplastron  was  first  described  by  Hay  as  a  nuchal.  Case  figured  a  more 
complete  specimen  as  a  nuchal.  This  was  found  lying  with  its  wings  overlapping  the  anterior 
ends  of  the  hyoplastra  (fig.  250).  It  extended  from  side  to  side  a  distance  of  599  mm.  The 
greatest  breadth  of  the  wings  was  131  mm.  From  the  midline  of  the  bone  there  reacht  back- 
ward a  spine  which  must  have  attained  a  length  equal  to  that  of  the  wings.  The  outline  of  this 
bone  was  concave  in  front  to  middle  of  wings,  then  convex.     The  epiplastra  are  unknown. 

The  xiphiplastra  are  remarkable  bones.  Instead  of  extending  backward  and  gradually 
inward  as  they  do  in  the  Cheloniidae,  just  behind  their  articulation  with  the  hypoplastra  they 
turn  directly  inward  at  almost  a  right  angle,  to  meet  at  the  midline  by  an  overlapping  joint. 

The  limbs  of  this  species,  as  of  all  the  Protostegidae,  are  modified  for  permanent  residence 
on  the  seas. 


PROTOSTEGID^. 


197 


Cope  described  and  figured  the  humerus  and  some  other  hmb  bones.    Case  also  added  to 
our  knowledge  of  the  limbs ;  to  Wieland  most  of  all  we  are  indebted  for  their  complete  restora- 
tion.    The  materials  furnishing  his  observations  are  in  the  Carnegie  Museum,  at  Pittsburg. 
The  scapula,  with  its  procoracoid  process,  is  a  stout  bone.    The  coracoid  is  so  long  that  it 

reacht  the  pelvis.  The  humerus  is  greatly  modified,  resem- 
bling in  some  respects  that  of  Dermochelys.  The  fingers  are 
elongated  to  form  a  great  paddle  for  beating  the  sea.  The 
length  of  this  limb,  from  the  glenoid  cavity  to  the  tip  of  the  third 
finger,  is  estimated  by  Wieland  as  being  1060  mm.  The  greatest 
spread  of  the  fore  limbs  is  supposed  to  have  been  2500  mm.  For 
details  on  the  structure  of  the  flippers  the  student  is  referred 
toWieland's  paper  and  to  the  figure  here  presented  (fig.  251). 
Fig.  252,  reduced  from  Wieland's  paper,  represents  a 
humerus  of  Protostega  now  in  Carnegie  Museum.  The  total 
length  is  340  mm. 

Fig.  253,  taken  from  Wieland,  represents  the  hinder  limb 
and  the  pelvis.  Both  the  pelvis  and  the  limb  resemble  closely 
those  of  the  Cheloniidae.  The  ilium  is  a  stout  bone.  The 
ischium  and  the  pubis  appear  to  have  met  on  the  midline.  The 
hinder  limb,  in  comparison  with  the  fore  limb,  is  relatively 
longer  than  it  is  in  most  Cheloniidae.  The  greatest  spread  of 
the  hinder  flippers  is  given  as  1900  mm.  Wieland  thinks  that 
four  of  the  toes  were  clawed. 

Estimates  varying  greatly  have  been  made  regarding  the 
size  of  this  sea-turtle.  It  is  highly  probable  that  earlier  esti- 
mates made  by  Cope  and  Hay  were  too  great.  Cope  concluded 
that  his  specimen  had  a  total  length  of  12.83  feet,  about  3900 
mm.  From  the  specimen  studied  by  Hay  about  the  same  con- 
clusion was  reacht.  The  discovery  by  Case  that  the  plastron 
was  much  shortened  behind  caused  him  to  conclude  that  the 
total  length  was  considerably  less  than  had  been  supposed.  He  estimated  the  length,  including 
the  head,  as  about  2270  mm.  He  made  the  length  of  the  carapace  as  1640  mm.,  the  width  as 
12^5  mm.     However,  if  we  may  judge  from  the  carapace  described  by  Wieland,  the  width 


Fig. 


252. — Protostega  gig  as. 
Humerus.     xJ. 

e,  ecteplcondylar  passage. 


Fig.  253. — Protostega  gigas.     Pelvis  and  hinder  limb.     Xj. 

aiU,  astragalo-calcaneum;  fern,  femur;  fb,  fibula;  I-V,  the  digits;   ,7,  ilium;   isch,  ischium;   met,  metatarsals; 
p,  first  row  of  phalanges ;   /)u4,  pubis;    (/i,  tibia  ;    1-5,  tarsals  of  second  row. 

was  considerably  greater  than  the  length.  It  is  now  estimated  that  the  length  of  the  carapace 
of  the  Pittsburg  specimen  was  about  iioo  mm.  and  the  width  about  1200  mm.  The  total 
length  of  the  animal  then  must  have  been  perhaps  something  over  2  meters.  Its  humerus 
was  340  mm.  long;  that  of  Cope's  type,  300  mm. 


198 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


As  regards  its  habits,  we  may  safely  conclude  that  this  turtle  was  an  active  swimmer  on  the 
open  seas  and  that  it  was  carnivorous  in  its  diet.  Wieland  is  of  the  opinion  that  all  the  members 
of  this  group  were  powerfully  equipt  for  both  swimming  and  attack,  and  may  well  have 
hunted  actively  swimming  prey.  As  to  swimming,  we  must  remember  that  the  boldest  swimmer 
among  turtles  of  our  day  is  the  leatherback,  which  has  an  elongated  body.  The  short,  broad 
carapace  of  Protostega  must  have  imparted  to  the  animal  an  unsteady  bearing  under  efforts  to 
make  rapid  progress. 

As  regards  the  nature  of  the  food,  the  long  symphysis  of  the  lower  jaw  appears  to  indicate 
a  habit  of  crushing  hard-shelled  animals,  such  as  crustaceans  and  mollusks. 

Protostega  potens  sp.  nov. 
Figs.  246,  254,  255. 

This  species  has  as  its  type  No.  180  of  the  American  Museum  of  Natural  History.  This 
was  collected  by  Mr.  H.  T.  Martin,  in  1897,  in  the  Niobrara  beds,  near  Elkader,  Logan 
County,  Kansas.  The  individual  is  represented  by  large  portions  of  the  skeleton,  but  only  a 
part  of  it  has  been  prepared  for  study. 

There  is  present  the  hinder  half  of  the  left  side  of  the  skull.  This  is  strongly  crusht  down- 
ward and  toward  the  right  side.    The  structure  appears  to  be  in  general  the  same  as  in  P. 


Figs.  254  and  255. — Protostega  potens.     Basioccipital  and  hyoplastron  of  type. 
254.  Section  across  front  of  basioccipital.     Xi-  255.  Hyoplastron.     Xj. 

gigas.  Sutures  are  not  discernible,  but  from  the  striations  on  the  bones,  their  limits  may  be 
pretty  accurately  determined.  The  orbit  had  a  perpendicular  diameter  of  70  mm.  The  dis- 
tance from  the  hinder  border  of  the  orbit  to  the  posterior  angle  of  the  squamosal  was  nearly 
200  mm.  On  lifting  the  anterior  end  of  the  parietal  there  is  exposed  a  broad  plate  of  bone 
which  runs  downward  from  the  inner  border  of  the  parietal.  This  is  without  doubt  the  descend- 
ing plate  of  the  parietal,  whose  presence  has  hitherto  been  somewhat  doubtful.  The  occipital 
condyle  is  large,  having  a  diameter  of  50  mm.  The  bones  composing  it  are  wholly  co-ossified. 
Its  inferior  portion  is  eroded  away.  The  condyle  is  broadly  rounded  behind,  without  trace 
either  of  a  pit  or  of  division  into  its  constituent  three  bones.  The  lower  surface  of  the  basi- 
occipital appears  to  have  been  greatly  different  from  that  of  P.  gigas.  Case  describes  the  latter 
as  having  its  under  surface  nearly  smooth  and  lying  in  the  plane  of  the  horizontal  axis  of  the 
skull.    From  this  we  may  infer  that  this  surface  is  nearly  flat.    In  the  present  species  the  midline 


protostegidj?;.  199 

of  the  bone  is  traverst  by  a  prominent  ridge,  the  summit  of  which  anteriorly  is  about  10  mm. 
wide  and  which  expands  posteriorly  to  the  condyle.  The  sides  of  the  ridge  are  formed  by  two 
bold  grooves  which  run  backward  and  outward  from  the  front  of  the  bone.  Whether  or  not  any 
portion  of  the  basisphenoid  is  present  in  the  fragment  of  bone  60  mm.  long  from  the  occipital 
condyle  is  not  certain.  Fig.  254  is  a  section  taken  near  the  front  of  the  fragment.  The  summit 
of  the  ridge  has  been  eroded  off. 

The  carapace  is  represented  by  the  midline  and  the  ribs  of  the  left  side.  It  resembled  that 
of  P.  gigas,  as  represented  by  Wieland,  but  the  ribs  are  free  from  one  another  to  points  nearer 
the  midline.  The  neurals  are  crusht  down  against  the  vertebrae  and  most  of  them  have  been 
subsequently  eroded  away.  The  boundaries  of  none  can  be  traced.  The  distance  from  the 
base  of  the  first  rib  to  that  of  the  tenth  is  close  to  800  mm.;  the  length  of  the  first  rib  is  205  mm., 
that  of  the  fifth  at  least  655  mm.  The  carapace  must  have  had  a  length  of  about  1250  mm. 
and  a  width  of  about  1500  mm.  The  ribs  are  free  from  the  adjoining  ones  to  about  120  mm. 
of  the  midline. 

Large  portions  of  the  plastron  are  preserved,  but  all  have  not  yet  been  made  available  for 
study.  The  right  hypoplastron  is  nearly  complete.  Its  lower  surface  is  traverst  by  a  low 
longitudinal  ridge.  The  length  of  the  bone  along  this  ridge  is  400  mm.  The  width  is  nearly  as 
great.  The  right  and  left  borders  are  furnisht  with  numerous  digitations.  At  the  hinder  end 
is  a  notch  for  the  reception  of  the  xiphiplastron.  Most  of  the  process  of  the  hypoplastron 
which  joined  the  xiphiplastron  on  its  outer  border  is  broken  away. 

The  xiphiplastron  (fig.  246,  xiph)  is  remarkably  thin,  being  nowhere  more  than  10  mm. 
thick.  It  is  not  so  abruptly  turned  toward  the  midline  after  being  freed  from  the  hypoplastron 
as  is  that  of  P.  gigas.  Its  length  was  originally  close  to  375  mm.  Beyond  the  hypoplastron 
both  of  the  borders  are  acute;  the  inner  is  the  thinner.  The  outer  border  joined,  for  more  than 
the  proximal  half  of  its  length,  a  process  of  the  hypoplastron. 

The  left  hyoplastron  (fig.  255)  is  present.  Unfortunately  many  digitations  are  lost,  so 
that  not  all  its  dimensions  are  determinable.  From  the  hyohypoplastral  suture  to  the 
anterior  end  the  length  is  580  mm.,  measured  on  a  straight  line.  From  the  just-named  suture 
to  the  bottom  of  the  axillary  notch  the  distance  is  300  mm.  The  entire  width  of  the  bridge  was 
not  far  from  625  mm.  The  low  ridge  seen  on  the  hypoplastron  is  continued  forward  on  the 
hyoplastron.  The  suture  between  the  hyoplastron  and  the  hypoplastron  was  evidently  consid- 
erably shorter  than  in  P.  gigas.    Here  the  bone  is  about  25  mm.  thick. 

The  T-shaped  entoplastron  (fig.  246)  is  preserved,  but  lacks  much  of  the  lateral  wings. 
The  lower  surface  is  mostly  convex,  but  on  the  outer  end  of  each  wing  it  is  slightly  concave  in 
all  directions.  The  visceral  surface  is  concave  from  side  to  side.  Near  the  front  border,  at 
a  distance  of  about  25  mm.  from  the  midline,  begins  a  broad  groove,  quite  deep  at  first,  but 
becoming  shallower  on  the  wings.  This  was  almost  certainly  occupied  by  the  epiplastron. 
At  the  midline,  near  the  anterior  border,  the  bone  is  about  20  mm.  thick.  About  50  mm.  from 
the  midline,  on  each  side,  there  is  a  rough  surface,  as  if  for  a  ligament.  To  this  may  have  been 
tied  the  anterior  end  of  the  procoracoid  process  of  the  scapula.  At  the  outer  end  of  the  right 
wing,  as  preserved,  the  thickness  of  the  bone  is  only  6  mm.  Here  the  surface  which  was 
covered  by  the  epiplastron  is  65  mm.  wide. 

The  left  scapula,  without  the  procoracoid  process,  is  preserved.  Its  length,  from  the  upper 
end  to  the  glenoid  fossa,  is  275  mm.  The  coracoid  has  a  length  of  425  mm.,  and  a  small  portion 
of  the  distal  end  is  missing.  It  was  not  expanded  at  the  distal  end.  The  left  humerus  is  well 
preserved  and  not  much  crusht.  The  total  length  is  402  mm.;  from  the  head  to  the  distal  end, 
385  mm.  From  the  head  to  the  lower  end  of  the  radial  process  is  245  mm.  The  width  of  the 
distal  end  is  185  mm.  The  ectepicondylar  passage  is  a  foramen  with  a  large  opening  on  the 
articular  surface. 

One  femur,  much  distorted  by  pressure,  is  present.    Its  length  is  335  mm.    The  diameter 

of  the  shaft  is  50  mm. 

Protostega  advena  sp.  nov. 

Figs.  256-259. 

The  chelonian  remains  to  which  the  name  Protostega  advena  is  given  are  the  property  of 
Kansas  University  and  have  the  number  1209.     There  is  no  history  of  the  time  or  place  ot 


200 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


collection  or  of  the  collector.  There  is  no  doubt,  however,  that  the  specimen  was  obtained 
from  the  Niobrara  deposits  of  Kansas.  It  consists  (fig.  256)  of  the  greater  portion  of  the 
plastron,  12  peripherals,  2  or  3  neurals,  and  portions  of  2  costal  plates.  With  these  are  some 
other  bones  which  are  either  undetermined  or  they  doubtfully  appertain  to  the  specimen. 
The  hyoplastra  and  hypoplastra  closely  resemble  those  of  Protostega  gigas.  The  two  of 
these  bones  which  are  found  on  the  same  side  were  apparently  united  for  a  short  distance  by 
a  coarse  suture.  The  two  hyoplastra  evidently  came  close  together  along  the  midline;  but 
the  hypoplastra  were  widely  separated.  The  median  fontanel  has  therefore  extended  from 
the  hyoplastrals  to  the  xiphiplastrals.  The  latter  bones  are  not  so  elongated  as  in  modern 
sea-turtles  and  Chelydra,  nor  so  short  and  abruptly  incurved  as  in  Protostega  gigas.  The 
greatest  thickness  of  the  hyoplastrals  is  about  10  mm.  The  other  plastral  bones  are  thinner. 
There  are  no  longitudinal  carinae  on  the  plastron,  such  as  we  find  on  that  of  Caretta  caretta 


Figs.  256-259. — Protostega  advena.     Portions  of  type.     Xj. 

256.  Plastron  and  peripherals,  seen  from  above.      257.  Two  neurals.      258.  Costal  bone.      259.  Postfrontal. 

and  Protostega  gigas.  The  forms  and  positions  of  the  various  bones  may  be  seen  from  the 
figures.  The  distance  from  the  anterior  border  of  the  hyoplastron  to  the  hinder  border  of 
the  xiphiplastron  is  278  mm.    The  entoplastron  and  the  epiplastra  are  wanting. 

The  anterior  peripherals  of  both  sides  are  absent  from  the  materials.  On  the  right  side 
the  most  anterior  peripheral  present  appears  to  be  the  one  which  has  received  the  rib-end  of 
the  first  costal  plate.  This  is  provisionally  regarded  as  the  fourth  from  the  nuchal  bone. 
The  most  anterior  one  on  the  left  side  is  the  fifth.  On  the  left  side  one  is  believed  to  be  missing 
next  to  the  pygal;  while  on  the  right  side  three  in  front  of  the  pygal  are  supposed  to  be  gone. 
These  peripherals  prove  that  this  individual  is  not  a  young  Protostega  gigas,  since  they  are 
relatively  much  shorter  and  broader  than  are  the  corresponding  bones  of  the  latter  species. 
They  are  likewise  much  heavier  bones. 


PROTOSTEGID^.  201 

Each  of  the  peripherals,  except  the  posterior  three,  may  be  said  to  be  V-shaped  in  trans- 
verse section,  one  limb  of  the  V  extending  toward  the  edge  of  the  plastron,  the  other  inward 
and  upward  toward  the  costal  plate.  The  upper  plates  are  slightly  concave  above;  the  lower 
ones  somewhat  convex  below.  The  concave  and  the  convex  surfaces  of  each  peripheral  come 
together  to  form  a  sharp  edge,  and  the  border  of  the  carapace  so  formed  runs  from  the  fourth 
peripheral  to  near  the  pygal.  The  three  posterior  peripherals  have  no  lower,  or  plastral, 
plate  developt.  What  is  regarded  as  the  tenth  peripheral  has  a  half-pit  at  its  hinder  end. 
It  is  therefore  believed  that  the  rib-end  of  the  eighth  costal  was  swung  backward  to  be  inserted 
between  the  contiguous  ends  of  the  eleventh  and  the  twelfth  peripherals.  In  Caretta  this  rib- 
end  has  moved  backward  still  further  and  is  inserted  in  the  middle  of  the  last  peripheral. 

The  antepenultimate  peripheral  has  a  pit  for  the  rib-end  of  the  seventh  costal  near  its 
hinder  end  and  this  pit  lies  partly  in  the  anterior  end  of  the  penultimate  peripheral.  If  the 
eighth  costal  plate  is  regarded  as  sending  its  rib  to  the  last  peripheral,  the  next  peripheral  in 
front  has  no  rib-end  corresponding  to  it.  In  Caretta  it  is  the  antepenultimate  peripheral 
which  receives  no  rib. 

The  peripherals  are  smallest  posteriorly,  and  they  increase  in  size  as  far  forward  as  they 
are  represented.  The  fourth,  the  most  anterior  one  present,  has  its  two  plates  standing  at  an 
obtuse  angle  with  each  other;  the  fifth  has  them  at  nearly  right  angles,  the  others  at  less  than 
a  right  angle.  The  plastral  plate  of  the  fifth  is  37  mm.  wide,  the  carapacial  plate  is  30  mm. 
wide.  Two  long  narrow  peripherals  accompany  the  specimen,  but  they  appear  to  be  intrusive 
and  to  belong  to  Toxochelys.  Two  neurals  (fig.  257)  are  present,  probably  the  third  and  the 
fourth.  The  more  anterior  is  39  mm.  long  and  28  mm.  wide;  the  other  30  mm.  long  and  25 
mm.  wide.  The  middle  line  of  each  rises  into  a  low  carina,  which  on  the  more  anterior  one 
rises  into  a  tubercle.  The  hinder  end  of  the  anterior  neural  is  crost  by  a  narrow  dermal 
sulcus,  a  fact  which  shows  that  dermal  scutes  were  present.  The  peripherals  also  are  crost 
by  sulci,  but  these  are  broader  than  that  on  the  neural. 

The  pygal  is  a  rather  peculiar  bone,  being  nearly  square,  thick,  convex  on  the  hinder, 
or  upper,  surface,  and  with  a  thick  free  border.  It  is  27  mm.  high,  33  mm.  wide  and  11  mm. 
thick. 

With  the  remains  described  is  found  a  detacht  median  dorsal  tubercle  exactly  like  those 
occurring  in  the  dorsal  carina  of  Toxochelys;  but  it  is  regarded  as  foreign  to  the  specimen, 
having  probably  been  introduced  with  the  peripherals  just  mentioned. 

Fig.  258  represents  a  costal  plate  of  this  species.  It  will  be  seen  that  it  is  less  completely 
ossified  than  the  costals  of  our  modern  sea-turtles,  but  more  completely  than  in  even  a  large 
Protostega  gtgas.  In  the  figure  the  distal  end  is  restored  in  outline  from  another  costal  present. 
Measured  thru  the  middle  of  the  width  the  costal  is  7  mm.  thick,  but  near  the  sutural 
border  it  becomes  reduced  to  3  mm.  The  costal  figured  is  probably  the  fifth  of  the  right  side. 
On  it  are  found  the  sulci  which  separated  two  vertebral  scutes  from  each  other  and  from  a 
costal  scute.  These  sulci  are  narrow  and  shallow.  It  is  evident  that  the  vertebral  scutes 
were  relatively  very  broad,  about  1 10  mm.,  nearly  equal  to  one-third  the  width  of  the  carapace. 

There  are  present  two  bones  which  are  referred  to  the  skull;  they  are  the  two  postfrontals 
(fig.  259).  Each  is  30  mm.  wide  and  60  mm.  long.  At  the  hinder  end  the  bone  thins  down 
to  a  sharp,  nearly  smooth  edge;  so  that  it  becomes  probable  that  this  edge  formed  the  hinder 
border  of  the  roof  of  the  temporal  region;  and  hence,  that  the  squamosal  did  not  join  the 
parietal.    The  roof  was  probably  not  so  extensive  as  in  Caretta. 

In  the  Cope  collection  of  the  American  Museum  of  Natural  History  is  the  left  humerus 
of  a  small  sea-turtle  which  was  collected  in  Gove  County,  Kansas,  in  1877,  by  one  of  Professor 
Cope's  collectors.  This  humerus  has  every  appearance  of  being  that  of  an  adult  turtle.  It  has 
suffered  no  compression  or  distortion  whatever.  Its  length,  from  the  proximal  surface  of  the 
head  to  the  distal  end  of  the  bone,  is  64  mm.  The  ulnar  process  rises  slightly  above  the  head. 
The  radial  process  descends  35  mm.  below  the  proximal  surface  of  the  head.  This  process 
is  II  mm.  thick.  The  width  of  the  humerus  across  this  process  is  23  mm.  Just  below  the 
process  the  width  is  16  mm.  On  the  upper  surface  of  the  bone,  opposite  the  radial  process, 
is  a  deep  muscular  scar.  At  the  distal  end  there  is  nearly  a  right  angle  between  the  surface 
for  the  radius  and  that  for  the  ulna.  The  ectepicondylar  passage  is  a  shallow  groove  close  to 
the  radial  border. 


202 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


A  wholly  similar  humerus  is  contained  in  a  small  collection  of  bones  sent  the  writer  from 
the  University  of  Chicago.  The  few  skeletal  bones  accompanying  it  are  not  sufficient  to 
identify  the  humerus  as  that  of  P.  advena,  but  it  seems  probable  that  both  it  and  the  humerus 
in  the  American  Museum  belong  here. 

Genus  ARCHELON  Wieland. 

Premaxillary  beak  more  strongly  developt  than  in  Protostega.  Crushing-surface  of  upper 
jaw  mostly  on  the  premaxillaries;  that  on  the  maxillae  extending  back  only  to  opposite  the 
choanae.  Lower  jaw  with  the  rami  not  co-ossified  at  symphysis;  at  least,  not  until  old  age. 
Entoplastron  T-shaped,  with  the  anterior  border  concave  from  end  to  end.  Radial  process 
of  humerus  feeble. 

Type:      Archelon  tschyros  Wieland. 


Fig.  260. — Archelon  ischyros.     Carapace  with  the  entoplastron.     Xa'n. 

Archelon  ischyros  Wieland. 
Figs.  260-268. 

Archelon  ischyros,  V^lt.tAND,  Amer.  Jour.  Sci.  (4),  II,  1896,  p.  399,  plate  vi,  text-figs.  2-19;    ibid.,  IX, 

1900,  p.  237,  plate  ii,  text-figs.  1-3,  6;  ibid.,  xiv,  1902,  p.  99,  fig.  2;  ibid.,  xv,  1903,  p.  211,  fig.  i; 

Ann.  Carnegie  Mus.,  iv,  1906  (1907),  p.  8,  figs,  i,  4. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A., 

1902,  p.  440. 
Protostega  ischyros,  Williston,  Univ.  Gaol.  Surv.  Kansas,  11,  1897,  p.  246. — Wieland,  Anier.  Jour. 

Sci.  (4),  V,  1898,  p.  15,  plate  ii,  text-figs.  I,  2. 

We  owe  our  knowledge  of  this  species  to  the  study  and  the  publications  of  Dr.  G.  R. 
Wieland.  All  the  known  specimens  have  been  found  by  him  near  the  South  Fork  of  Cheyenne 
River  in  South  Dakota,  in  the  upper  beds  of  that  part  of  the  Pierre  formation  that  is  below 


PROTOSTEGID^. 


203 


the  Judith  River  formation.  The  species  was  probably  the  largest  that  is  at  present  known 
to  have  existed.  From  the  length  of  the  neck  and  the  carapace  Wieland  estimates  that  the 
total  length  of  type  specimen  was  about  3.5  meters.  Specimen  in  Yale  University  collection. 
Of  the  remains  of  this  great  turtle  the  present  writer  has  studied  only  the  skull.  The 
greater  part  of  the  description  here  given  has  been  derived  from  Wieland's  papers.  The 
figures  are  reproduced  from  those  papers.  Fig.  260  represents  the  carapace  as  shown  in 
Wieland's  latest  restoration  of  it  (Amer.  Jour.  Sci.,  xv,  p.  212).  In  this  figure  (p.  189)  a  large 
bone  is  shown  in  front  as  the  nuchal  but  which  the  present  writer  regards  as  the  entoplas- 
tron.  This  figure  is  based  on  the  type  specimen,  except  that  the  first  rib  is  added  from 
another  individual.  The  carapace,  so  far  as  is  known,  was  composed  of  8  neurals,  I  or 
more  suprapygals,  10  pairs  of  ribs,  a  nuchal,  a  pygal,  and  an  undetermined  number  of  pairs  of 
peripherals. 

The  estimated  total  length  of  the  carapace,  exclusive  of  the  nuchal,  is  1.7  meters;  with  the 
nuchal,  it  was  probably  about  1.9  meters.  The  width,  exclusive  of  the  peripherals,  must  have 
been  about  2  meters;  including  the  peripherals,  about  2.5  meters. 

The  neurals  are  mostly  broader  than  long.  Their  borders  are  furnisht  with  long  and 
coarse  digitations,  which  interlock  with  others  from  the  contiguous  neurals  and  costal  plates. 
It  is  difficult,  therefore,  to  determine  the  widths  of  the  neurals,  but  these  widths  may  be  taken 
as  from  175  mm.  to  225  mm.  The  neurals  are  relatively  thin,  being  only  about  5  mm.  The 
median  line  of  most  of  the  neurals  is  markt  by  a  deep  and  narrow  groove,  which  becomes 
widest  at  the  center  of  the  neural.  From  this  center  there  radiate  outward  characteristic 
surface  striations.  In  his  first  description  Wieland  thought  that  these  neurals  probably  con- 
sisted each  of  paired  bones.  He  concluded  also  that  the  longi- 
tudinal groove  was  filled  with  horny  materials  and  that  the  animal 
may  have  borne  a  row  of  dorsal  spines.  The  last  one  or  two 
neurals  and  the  suprapygals  have  not  been  well  determined. 
Little  can  be  said  concerning  the  pygal.  Indeed,  the  terminal 
bone  shown  in  Wieland's  figures  of  the  carapace  is  probably  a 
suprapygal. 

The  ribs  and  the  costal  plates  resemble  much  those  of  Pro- 
tostega.  The  disk  formed  of  the  costal  plates  and  the  neurals  is 
much  reduced,  extending  outward  from  the  median  line  hardly 
one-fifth  the  distance  to  the  ends  of  the  ribs  Beyond  the  borders 
of  the  disk  the  ribs  are  wholly  free  from  one  another.  The  first 
rib  is  extraordinarily  large,  as  compared  with  the  same  rib  in  other  turtles,  being  three-fourths 
as  long  as  the  second.  Its  length  is  740  mm.;  its  diameter,  about  75  mm.  The  other  ribs  have, 
in  the  type  specimen,  the  dimensions  shown  in  the  table. 

Where  the  ribs  emerge  from  the  disk  their  thickness  averages  only  about  25  mm.  It  is 
thus  seen  that  they  increase  much  in  thickness  toward  the  middle  of  their  length. 

The  bone  described  by  Wieland  (Amer.  Jour.  Sci.,  v.,  1898,  p.  17)  as  the  nuchal  (fig.  261) 
and  now  regarded  by  the  present  writer  as  such,  is  roughly  triangular,  with  a  concave  anterior 
border.  The  lateral  extent  of  the  bone  is  640  mm.;  its  antero-posterior  extent,  250  mm.  On 
the  inferior  surface  there  is  a  trapezoidal  elevation,  which  Wieland  regarded  as  having  afforded 
an  articulation  with  the  last  cervical  vertebra.  The  thickness  through  the  elevation  is  35  mm.; 
elsewhere,  from  10  mm.  to  15  mm. 

Little  has  yet  been  publisht  about  the  peripherals.  A  fragment  of  one  was  figured  by 
Wieland  in  his  earliest  description  of  this  turtle.  In  a  later  paper  (Amer.  Jour.  Sci.,  xv,  p.  2 1 1 ) 
he  states  that  the  inner  borders  of  these  bones  are  strongly  digitated. 

The  plastron  (Amer.  Jour.  Sci.,  v,  p.  16)  has  the  same  general  structure  as  that  of  Pro- 
tostega,  altho  the  principal  bones  appear  to  have  been  broader  and  to  come  nearer  filling  up  the 
median  fontanel  (fig.  262).  As  represented  by  Wieland,  the  digitations  bordering  them  are 
extraordinarily  numerous  and  elongated.  The  T-shaped  entoplastron  (fig.  262,  eni)  has  a 
breadth  of  940  mm.  and  a  length  of  450  mm.  The  anterior  border  is  concave  to  the  outer 
extremities,  thus  diff'ering  from  that  of  Protostega.  The  extremities  of  the  wings  are  280  mm. 
wide.    They  appear  in  the  figure  to  occupy  their  natural  position  on  the  hyoplastra.     The 


Rib. 

Length. 

Width  at 
middle  part. 

2 

950 

"1 
75 

3 

lOIO 

75 

4 

1020 

78 

5 

1020 

75 

6 

lOIO 

70 

7 

65 

8 



60 

9 

55 

10 

50 

204 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


greatest  thickness  of  the  entoplastron,  at  the  midline,  is  60  mm.;  at  the  narrowest  part  of  the 
lateral  portion,  50  mm.  The  epiplastra  probably  overlapt  the  entoplastral  wings  nearly  to  the 
midline  and  ran  backward  a  short  distance  on  the  borders  of  the  hyoplastra.  Wieland  (Ann. 
Carnegie  Mus.  iv,  p.  8)  describes  what  he  regards  as  the  epiplastron.  For  the  present  writer's 
opinion  on  this,  the  reader  is  referred  to  page  190. 

The  hyoplastra  (fig.  262,  hyo)  have  each  an  antero-posterior  length  of  1030  mm.;  while  the 
width,  inclusive  of  the  spines,  is  1 100  mm.  The  greatest  thickness  is  48  mm.  The  articulation 
with  the  hypoplastron  is  about  150  mm.  wide. 

The  hypoplastron  (fig.  262,  hypo)  from  the  hyoplastral  articulation  to  the  extremities  of 
the  processes  embracing  the  xiphiplastron,  has  a  length  of  about  960  mm.  The  greatest 
breadth,  including  the  spines,  is  1000  mm.;  the  greatest  thickness  is  41  mm. 


Figs.  261  and  262. — Archelon  ischyros.     Xso.     Nuchal  bone  and  plastron  of  type. 
261,  Nuchal  bone.  262.  Plastron,    ent,  entoplastron;    hyo,  hyoplastron;  hypo,  hypoplastron;   xiph,  xiphiplastron. 

The  xiphiplastra  (fig.  262,  xiph)  are  each  500  mm.  long,  170  mm.  wide,  and  36  mm.  thick. 
The  proximal  end  of  each  fits  in  between  processes  of  the  corresponding  hypoplastron,  being 
grooved  to  receive  the  borders  of  those  processes.  The  distal  ends  of  the  two  xiphiplastra  join 
at  the  midline  by  interlocking  digitations.  These  bones  are  less  abruptly  curved  than  are 
those  of  Protostega,  and  greatly  resemble  those  of  Protostega  advetia. 

The  total  length  of  the  plastron,  according  to  Wieland's  figure,  is  about  2100  mm.,  being 
thus  longer  than  the  estimated  length  of  the  carapace.    The  latter  was  certainly  the  longer. 

The  skull  (fig.  263)  of  this  species  reacht  an  enormous  size  both  relatively  to  the  length  of 
the  carapace  and  absolutely.  Wieland's  restoration  of  the  one  studied  by  him  is  here  repro- 
duced. The  same  individual  furnisht  also  a  nearly  complete  skeleton.  It  was  about  three- 
fourths  the  size  of  the  type  specimen.  The  skull  has  a  length  of  720  mm.  Another,  but 
fragmentary  specimen,  indicated  a  skull  fully  a  meter  in  length. 


PROTOSTEGID^. 


205 


Points  to  be  especially  noted  in  this  skull  are  its  long  and  narrow  form,  the  long  preorbital 
region,  the  hookt  beak,  the  posterior  position  of  the  orbits,  and  the  upwardly  directed  nasal 
opening.    Contrary  to  what  is  usually  seen  in  turtles,  the  orbits  are  placed  in  the  middle  of  the 


sq- 


-pmx 


Fig.  263. — Archelon  ischyros.     Skull.     Xj. 

an^,  angular;  art,  articular ;  <f«n,  dentary;  /r,  frontal;  ^u,  jugal ;  mx,  maxilla;  nar, 'nares;  pr/,  "prefrontal;  pal, 
palatine;  pmx,  premaiilla;  pa,  parietal;  poj,  postfrontal;  qu,  quadrate;  quj,  quadratojugal;  sq,  squamosal; 
J/,  stapedial  rod ;   J«r,  supraangular;  vom,  vomer. 

length  of  the  head.    This  results  from  the  great  development  of  the  preorbital  region.    The 
horizontal  diameter  of  the  orbit  is  150  mm. 

Both  the  maxillae  and  the  premaxillae  are  greatly  prolonged.     The  distance  from  the  tip 
of  the  beak  to  the  anterior  rim  of  the  orbit  is  240  mm. ;   from  the  orbit  to  the  suture  between  the 


Figs.  264  AND  265.     Archelon  ischyros.    Skull. 

264.  Palatal  surface.  Xj's.  bsp,  basisphenoid;  cho,  cho- 
an^;  y'u,  jugal;  mx,  maxilla;  of,  occipital  condyle; 

pal,  palatine;  pmx,  premaxilla;  pi,  pterygoid;  qu, 
quadrate;  yw/",  quadratojugal ;  5y,  squamosal;  vom, 
vomer;  vp,  vomero-palatine  region. 

265.  Side  view  of  front.  X\.  mx,  maxilla;  nar,  nares; 
0,  orbit;  pal,  palatine;  pmx,  premaxilla;  prf,  pre- 
frontal; vom,  vomer. 

maxilla  and  the  premaxilla  is  about  150  mm.  The  tip  of  the  premaxillx  is  bent  down  at  nearly 
a  right  angle  with  the  axis  of  the  skull,  forming  a  great  hawk-like  beak.  The  nasal  opening 
looks  wholly  upward.    Its  length  is  120  mm.;  its  width,  70  mm. 


2o6 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


From  the  front  of  the  orbit  to  the  quadrate  the  free  borders  of  the  maxilla,  the  jugal,  and 
the  quadratojugal  form  a  nearly  straight  line.  Above  the  orbit  the  prefrontal  meets  the 
postfrontal,  thus  excluding  the  frontal  from  the  orbital  rim.  The  relations  of  the  bones  behind 
the  orbit  are  in  general  like  those  oi Protostega.  In  describing  the  (juadratojugal  of  Protostega 
Case  appears  to  have  inverted  the  bone  and  this  has  led  Wieland  to  suppose  that  the  bone 
mentioned  and  others  of  the  region  are  different  in  Archelon.  Wieland's  figure  of  the  skull 
oi Protostega  show^s  that  the  region  in  question  is  the  same  in  both  genera.  The  squamosal  is 
figured  by  Wieland  as  sending  a  process  upward  to  meet  the  parietal.  Probably  the  same 
occurs  in  Protostega.  The  supraoccipital  is  represented  as  very  short,  but  there  is  probability 
that  it  was  longer.    The  width  across  the  quadrate  region  is  about  350  mm. 

Various  interesting  structures  appear  on  the  palatal  surface  of  the  skull  (figs.  264,  265). 
As  in  Protostega,  the  basioccipital  was  small.  The  basisphenoid  too  appears  to  have  been 
small,  but  it  is  not  well  known.    The  pterygoids  are  extremely  narrow.    The  exact  relationships 


Fig.  266. — Archelon  ischyros.     Shoulder-girdle,  humerus,  and  a  cervical  vertebra.      Xi'n. 

cer.Vj  third  or  fourth  cervical  vertebra;    the  figure  on  the  right  giving  front  view,  that  on  the  left  a   side  view. 
cor,    coracoidj  hum,  humerus;   scap,  scapula. 

of  the  palatines  are  not  known.  The  hinder  end  of  the  vomer  is  missing,  but  it  is  probable  that 
it  interposed  between  the  palatines.  The  choanae  were  placed  far  forward,  immediately  below 
the  external  nares,  and  were  not  underfloored  by  the  surrounding  bones.  The  great  crushing- 
surface  of  the  upper  jaw  was  developt  mostly  on  the  premaxillaries,  an  unusual  thing  among 
the  turtles.  On  the  maxilla  this  surface  extends  backward  only  to  opposite  the  choanae. 
Behind  these,  the  free  border  of  the  maxilla  is  narrow  and  weak.  The  crushing-surface  was 
therefore  about  240  mm.  long  and  about  140  mm.  wide  across  the  vomer.  The  anterior  portion 
of  the  vomer  formed  a  boss  in  the  center  of  the  crushins-surface. 

The  lower  jaw  (fig.  263)  was  massive.    Its  lateral  halves  were  not  co-ossified,  thus  differing 
from  those  oi  Protostega.    The  symphysis  has  a  length  of  120  mm.,  the  total  length  of  the  jaw 


PROTOSTEGID^. 


207 


being  465  mm.  At  the  hinder  end  of  the  symphysis  its  depth  is  no  mm.,  and  the  width  of 
the  jaw,  155  mm.  On  the  under  surface  the  symphysial  end  of  the  jaw  turns  strongly  upward, 
but  the  upper  surface  rises  little.    Wieland  found  the  splenial  to  be  present. 

Wieland  has  described  5  cervical  vertebrae  (fig.  266,  cer.  v)  which  belonged  to  the  type 
specimen  (Amer.  Jour.  Sci.,  11,  p.  401;  xiv,  p.  102).  These  centra  indicate  a  neck  of  great 
strength.  The  centrum  of  one,  regarded  as  the  third  or  the  fourth,  is  procoelous,  95  mm.  long 
and  140  mm.  wide.    Dorsal,  sacral,  and  caudal  vertebrae  also  are  described  by  the  same  author. 

The  shoulder-girdle  of  the  type  specimen  was  described  by  Wieland  (Amer.  Jour.  Sci., 
II,  p.  404).  The  scapula  (fig.  266,  scap)  is  a  stout  and  heavy  bone,  resembling  that  of  Pro- 
tostega.  The  length  of  the  body  of  this  bone,  from  the  upper  end  to  the  glenoid  fossa,  is 
450  mm.  The  coracoid  (fig.  266,  cor)  is  elongated  and  slender,  as  in  Protostega.  The  length  is 
650  mm.,  the  width  of  the  distal  end,  127  mm. 


Fig.  267. — Archelon  ischyros.     Limb  bones.     X  I'o. 

fern',  left  femur,  dorsal  surface  ;  fern",  left  femur,  tibial  border ;  jem"',  proiimal  end  of  left  femur,  fibular  border  ; 
fh,  fibula  ;  hum,  left  humerus ;  rad,  ulna  ;  tih,  tibia  ;  ul,  radius.  The  bones  marked  rad  and  ul  should 
exchange  places,  be  placed  with  the  other  ends  up,  and  exchange  explanatory  letters. 

The  humerus  (figs.  266,  267,  hum)  is  an  enormous  bone,  the  length  from  the  head  being 
580  mm.;  the  total  length,  650  mm.  The  width  of  the  distal  end  is  340  mm.  This  bone  differs 
from  that  oi  Protostega  in  having  a  relatively  smaller  head  and  the  radial  process  much  reduced. 
Wieland  describes  also  the  radius,  the  ulna,  and  some  phalangeal  bones.  The  figures  by 
Wieland  are  here  reproduced.  In  the  figure  of  the  fore  Hmb  the  upper  ends  of  the  ulna  and 
the  radius  have  mistakenly  been  represented  as  the  lower.  When  the  ends  are  reversed  they 
will  have  the  positions  that  they  have  in  Wieland's  figure  of  the  anterior  flipper  of  Protostega 
gigas.     The  bones  must  also  exchange  places  and  legends. 

The  pelvis  of  the  type  specimen  is  described  and  figured  in  the  journal  so  often  quoted 
(vol.  IX,  p.  247).  The  figure  is  here  reproduced  (fig.  268).  This  pelvis  is  of  astonishing  size, 
the  length  and  the  width  being  each  nearly  half  the  length  of  the  carapace.    In  general,  its 


208  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

Structure  resembles  that  of  the  pelvis  of  the  Cheloniidae,  but  it  differs  in  having  a  median 
bridge  of  bone  connecting  the  pubes  and  the  ischia.  In  this  way  ischio-pubic  foramina  are 
formed,  but  they  are  of  small  size.  As  stated  by  Wieland,  the  extreme  antero-posterior  length 
of  the  pelvis  is  970  mm.;  the  extreme  width,  810  mm.  The  fore-and-aft  length  of  the  pubis 
is  460  mm.  The  length  of  the  ilium  is  300  mm.,  and  its  diameter,  at  the  middle  of  the  shaft, 
is  105  mm. 

The  femur  (fig.  267,  fern)  has  the  ratio  to  the  humerus  that  it  has  in  Caretta  caretta.  Its 
extreme  length  is  460  mm.  The  tibia  (fig.  267,  tih)  has  a  length  of  330  mm.;  the  fibula  (fig.  267, 
fib)  a  length  of  310  mm. 

As  in  the  case  of  Proiostega,  we  can  not  doubt  the  adaptation  of  this  turtle  to  marine 
aquatic  life.     Its  excursions  on  land  must  have  been  confined  to  those  for  the  deposition  of 


Fig.  268. — Archelon  ischyros.     Pelvis  seen  from  below.     Xi*o. 
it,  Qium;  ip,  ischio-pubic  foramen;  isch,  ischium;  pub,  pubis. 

its  eggs.  We  can  only  speculate  as  to  what  extent  it  spent  its  life  on  the  high  seas  away  from 
the  coasts.  It  seems  probable  that  the  broad  and  heavy  body  and  the  ponderous  head  were 
obstacles  in  the  way  of  sustained  journeys  over  rough  seas.  Its  prolonged  beak,  furnisht 
with  a  broad  crushing-surface,  appears  to  indicate  a  diet,  not  of  soft  and  actively  swimming 
animals,  but  of  mollusks  and  crustaceans.  Associated  with  the  fossil  were  various  genera  of 
tetrabranchiate  cephalopods,  and  the  jaws  of  the  turtle  seem  to  have  been  admirably  adapted 
to  pick  up  and  crush  such  objects. 

Archelon  marshi  Wieland. 

Archelon  marshii,  Wieland,  Amer.  Jour.  Sci.  (4),  ix,  1900,  p.  248;  ibid.,  xv,  1903,  p.  215. — Hay, 
Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  440. 

This  species  was  secured  by  Wieland  in  the  upper  beds  of  the  Pierre  formation,  in  South 
Dakota,  on  the  east  side  of  the  South  Fork  of  the  Cheyenne  river.  It  is  described  in  the 
briefest  terms.  The  remains  are  stated  to  consist  of  the  plastron,  the  humerus,  ribs,  and  a 
number  of  peripherals.  These  indicate  a  turtle  about  1 1  feet  in  length.  The  humerus  is 
said  to  be  rather  straighter  than  that  o{  J.  ischyros  and  the  plastron  relatively  more  massive, 
being  fully  one-half  thicker  than  in  the  latter  species. 

Family  CHELONIIDJE  Gray. 

Thecophorous  turtles  fitted  for  life  on  the  sea.  Skull  with  temporal  region  extensively 
rooft  over.    No  nasal  bones.    No  posterior  palatine  foramina.    Quadrate  notcht  behind  for 


CHELONIID^.  209 

the  stapedial  rod.  Choanae  placed  on  the  line  joining  the  centers  of  the  orbits;  the  nasal 
passages  underfloored  by  plates  from  the  vomer  and  the  palatines.  Neck  short,  head  not 
retractile.  Carapace  heart-shaped,  excavated  in  front  for  the  neck  and  for  the  fore  limbs; 
often  with  costo-peripheral  fontanels.  Plastron  loosely  and  ligamentously  joined  to  the  cara- 
pace; usually  with  median  and  lateral  fontanels.  Entoplastron  small  and  lance-shaped. 
Limbs  unfitted  for  locomotion  on  the  land;  converted  into  paddles  for  swimming;  the  anterior 
the  more  powerful.  Humerus  straightened  and  flattened;  with  the  head  nearly  in  the  axis 
of  the  bone  and  with  the  ulnar  and  radial  processes  nearly  in  the  plane  of  the  distal  end; 
the  radial  process  below  and  free  from  the  head.  Second  to  fifth  fingers  elongated,  the  phalanges 
without  condyles;    and  all  bound  together  in  the  skin  and  muscles.     Claws  I  or  2. 

At  the  present  day  the  Cheloniidae  are  represented  by  probably  4  genera  {Eretmochelys, 
Colpochelys,  Caretta,  and  Chelonia)  and  5  or  6  species.  Most,  if  not  all,  of  these  species 
enjoy  a  wide  distribution,  being  found  in  all  tropical  and  subtropical  seas.  All  are  seafaring 
animals,  coming  on  the  land  only  to  deposit  their  eggs.  They  are  mostly  carnivorous  in  their 
food  habits,  but  Chelonia  feeds  on  vegetation. 

If  Allopleuron  hoffmanni,  of  Holland,  belongs  to  this  family,  as  usually  supposed,  the 
family  history  extends  backward  to  Upper  Cretaceous  times.  Well-preserved  remains  of 
sea-turtles  belonging  to  the  divisions  of  the  Tertiary  are  not  common.  In  America  we  have 
a  few  species  which  are  here  assigned  to  the  family  with  some  doubt;  such  as  those  of  Peri- 
tresius  of  the  Upper  Cretaceous  of  New  Jersey  and  Georgia  and  Lembonax  of  the  Eocene  of 
New  Jersey.  It  can  hardly  be  doubted  that  Syllomus  crispatus  of  the  Miocene  of  Virginia 
belongs  to  the  family;  while  it  is  probable  that  the  species  here  called  Procolpochelys  grandava 
and  Chelonia  parviiecta  are  also  true  Cheloniidae.  All  of  these  are,  however,  imperfectly 
known.     In  Europe  the  known  Tertiary  forms  are  hardly  more  numerous  or  better  known. 

Allopleuron  hoffmanni  is  greatly  specialized  in  some  respects.  Especially  is  its  carapace 
much  reduced.  It  is  improbable  that  from  it  have  been  derived  the  modern  Cheloniidae. 
It  is  more  likely  that  the  latter  have  descended  from  some  Upper  Cretaceous  ancestor  not 
distant  from  Toxochelys.  The  ancestors  of  Allopleuron  must  have  become  sea-turtles  long 
before  the  Upper  Cretaceous— consequently  long  anterior  to  the  time  when  the  ancestors 
of  our  modern  Cheloniidae  could  be  called  sea-turtles.  It  is  therefore  probable  that  Allo- 
pleuron really  belongs  to  a  family  distinct  from  the  Cheloniidae. 

Key  to  Genera  here  Described. 

A.    First  costal  articulating  with    peripherals.      Shell   coarsely    sculptured    as  in  some 

Trionychids Per'tresius 

A  A.  Costal  plates  articulating  to  peripherals  and  sculptured Syllomus 

AAA.  Costal  bones,  so  far  as  known,  not  articulating  with  peripherals  and  not  sculptured. 

a.   Plastral  bones  without  median  digitations Lembonax 

aa.  Plastral  bones  with  median  digitations. 

b    Some  neurals  in  contact  with  three  pairs  of  costals.    Rib  of  first  costal  entenng 

pit  in  third  peripheral ;■•••.  Procolpochelys 

bb    Neurals  in  contact  with  two  pairs  of  costals.    Rib  of  first  costal  entenng  pit  in 

third  peripheral Chelor„a 

Genus  PERITRESIUS  Cope. 

Carapace  cordate,  as  in  the  Cheloniidae  generally;  the  anterior  peripherals  suturally 
joined  to  the  costals  of  the  first  pair;  the  posterior  peripherals  joined  to  costals  by  gomphosis 
of  ribs  only;    a  high  dorsal  keel;    surface  of  carapace  coarsely  sculptured. 

Type:     Chelone  ornatus  Leidy. 

In  1882  (Proc.  Amer.  Philos.  Soc,  xx,  p.  144)  and  again  in  1884  (Vert.  Tert.  Form. 
West,  p.  112)  Cope  characterized  this  genus  as  having  9  pairs  of  costals,  2  anterior  peripherals 
joined  to  the  costals,  and  a  high  dorsal  keel.  It  is  now  evident  that  he  had  derived  his  mfor- 
mation  from  a  carapace  sent  to  him  by  Dr.  George  Little,  at  one  time  State  Geologist  ot 
Georgia  (Amer.  Naturalist,  ni,  1878,  p.  129). 
14 


210  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

Cope  arranged  this  genus  among  his  Propleuridae.  The  cordate  form  of  the  carapace 
in  the  state  collection  at  Atlanta,  deeply  excavated  in  front  and  pointed  behind,  appears  to 
indicate  close  relations  with  the  Cheloniidae,  and  to  this  family  the  species  is  here  provisionally 
assigned. 

Peritresius  ornatus  (Leidy). 

Chelone  ornatus,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1856,  p.  303;    Smithson.  Contrib.  Knowl.,  xiv, 

1865,  pp.  105,  119,  plate  xviii,  fig.  10. 
Peritresius  ornatus,  CoPE,  Cook's  Geol.  Nays'  Jersey,  1868  (1869),  p.  735;   Amer.  Naturalist,  III,  1869, 

p.  88;   Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1870,  p.  150;   Vert.  Cret.  Form.  West,  1875,  p.  260; 

Amer.  Naturalist,  111,  878,  p.  129. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  441. 

This  is  yet  an  imperfectly  known  species.  It  was  based  by  Leidy  on  conjoined  portions 
of  two  lateral  peripherals,  which  had  been  found  in  Cretaceous  greensand  in  Burlington 
County,  New  Jersey.  This  greensand  probably,  but  not  certainly,  belonged  to  the  upper 
bed.  The  bones  are  probably  now  in  the  collection  of  the  Philadelphia  Academy,  but  they 
have  not  been  seen  by  the  present  writer.  They  were  described  by  Leidy  as  measuring  an 
inch  and  a  half  in  breadth  and  as  being  wedge-shaped  in  section.  The  outer  border  was 
acute;  the  inner  border  grooved,  and  eight  lines,  about  17  mm.,  high.  Both  the  upper  and  the 
lower  surfaces  were  coarsely,  but  beautifully,  tuberculated,  and  the  tubercles  showed  a  tendency 
toward  a  radiate  arrangement.  Some  of  the  tubercles  at  the  ends  of  the  peripherals  are 
lengthened  out  into  ridges.  Cope  states  that  there  were  no  indications  of  dermal  sulci  on  the 
bones.     He  mentions  also  a  costal  which  he  thought  belonged  at  least  to  the  genus. 

Under  the  species  Taphrosphys  nodosus  the  present  writer  has  suggested  that  it  may  be 
identical  with  the  species  here  described. 

In  the  collection  of  the  Geological  Survey  of  Georgia  is  the  greater  portion  of  the  carapace 
of  what  appears  to  have  been  a  large  sea-turtle.  This  specimen  was  at  one  time  in  the  hands 
of  Prof.  E.  D.  Cope  and  was  by  him  identified  as  Peritresius  ornatus  Leidy  (Amer.  Naturalist 
III,  1878,  p.  129).  Considering  the  facts  that  Leidy's  type  consisted  of  portions  of  two 
evidently  hinder  peripherals  and  that  all  the  hinder  peripherals  of  the  Georgia  specimen  are 
wanting  we  can  not  be  sure  that  the  identification  is  correct.  For  the  present  it  may  be  allowed 
to  stand.  Undoubtedly  it  was  on  this  specimen  that  Cope  based  his  definition  of  the  genus 
Peritresius.     It  is  not  known  why  Cope  concluded  that  there  were  9  pairs  of  costals. 

The  specimen  here  described  was  found  by  Mr.  Loughridge,  of  the  Georgia  Geological 
Survey,  then  under  the  direction  of  Dr.  George  Little,  in  the  Ripley  formation  of  the  Upper 
Cretaceous,  on  Bonnahachee  Creek,  Stewart  County,  Georgia.  It  presents  most  of  the  carapace, 
but  unfortunately  the  left  side  is  yet  concealed  by  a  mass  of  matrix.  This  has  prevented  an 
accurate  study  of  the  specimen  and  the  production  of  a  figure.  The  length  of  the  portion  pres- 
ent is  675  mm.  in  a  straight  line,  735  mm.  over  the  curve.  The  original  length  of  the  carapace 
must  have  been  about  900  mm.  In  form  the  carapace  is  cordate,  like  that  o(  Caretta.  Anteriorly 
there  is  an  excavation  in  the  border  200  mm.  wide  and  about  30  mm.  deep.  The  free  border  is 
obtuse  and  the  bone  is  about  16  mm.  thick.  The  costals  are  about  8  mm.  thick.  The  anterior 
peripherals  are  suturally  joined  to  the  first  costals.  Behind  this  they  are  missing;  but  it  is 
evident  that  some  of  them  were  connected  with  the  costals  only  by  gomphosis  of  the  ribs. 

The  most  conspicuous  feature  of  the  carapace  is  the  great  dorsal  keel.  This  begins  on  the 
nuchal  bone  and  continues  to  the  rear  of  the  carapace.  It  is  thick  and  obtuse  on  the  anterior 
half  of  the  carapace.  Here  the  sloping  sides  of  the  keel  are  very  steep,  the  summit  is  obtuse, 
and  the  height  is  about  36  mm.    Posteriorly  the  summit  is  more  acute. 

On  account  of  the  great  number  of  fractures  it  is  difficult  to  follow  the  sutures.  Where 
observed  these  are  coarse  and  zigzag.  A  few  of  the  sulci  are  traceable.  The  third  vertebral 
scute  has  a  width  of  about  125  mm.  The  sulci  forming  its  lateral  boundaries  are  nearly  parallel 
with  the  axis  of  the  animal. 

The  whole  upper  surface  of  the  carapace  is  coarsely  pitted  and  ridged,  much  like  that  of 
some  species  of  Trionychidae.    5  or  6  ridges  are  usually  to  be  counted  in  a  line  25  mm.  long. 

The  anterior  border  of  a  second  specimen  is  in  the  same  collection.  Found  with  it  is  the 
greater  portion  of  the  united  dentary  bones.  The  triturating  surfaces  are  flat.  The  length 
of  the  symphysis  is  53  mm. 


CHELONIIDii;.  211 

The  writer  has  been  permitted  to  examine  these  specimens  thru  the  courtesy  of  the 
present  state  geologist,  Prof.  WilHam  S.  Yeates. 

In  the  American  Museum  of  Natural  History  is  a  small  collection  of  bones,  without  indi- 
cation of  origin,  but  which  are  provisionally  assigned  to  the  present  species.  The  number  of 
the  lot  is  1410.  They  are  a  part  of  the  Cope  collection  and  evidently  were  found  in  New  Jersey. 
These  bones  are  filled  with  iron  pyrites  and  they  are  black,  with  some  surface  stain  of  chocolate. 
One  fragment  is  that  of  a  costal.  The  sutural  border  is  12  mm.  thick,  but  thru  the  rib 
the  thickness  is  17  mm.  The  upper  surface  is  covered  with  coarse  ridges  and  tubercles, irregular 
in  size  and  arrangement.  They  resemble  greatly  those  of  Arnyda  •uirgtniana  illustrated  on 
plate  96,  figs.  7,  8.  Another  fragment  appears  to  be  the  upper  end  of  a  costal,  with  the  base 
of  the  rib-head.  The  thickness  varies  from  7  mm.  to  10  mm.  The  fragment  is  75  mm.  wide. 
Another  piece  seems  to  be  a  part  of  a  peripheral,  showing  the  acute  free  border,  but  not  extend- 
ing to  the  costal  border.  The  length  of  the  fragment  is  56  mm.;  the  width,  63  mm.;  the  thick- 
ness of  the  upper  border,  21  mm.  The  upper  surface  is  convex  from  the  free  border  upward, 
while  the  lower  surface  is  concave.  One  end  appears  to  have  come  close  to  the  suture,  and 
here  the  tubercles  run  at  right  angles  with  the  suture.  Those  at  the  outer  end  are  small  and  less 
elongated.   Between  the  two  regions  are  some  ridges  running  at  right  angles  with  the  free  border. 

Three  fragments  belong  to  the  plastron.  The  best  of  these  resembles  the  outer  end  of  the 
left  hyoplastron  of  the  loggerhead.  The  fragment  is  135  mm.  long,  67  mm.  wide,  and  20  mm. 
thick  at  the  proximal  end.  Toward  the  outer  end  the  bone  thins  and  ends  in  a  number  of 
digitations.  The  border,  supposed  to  be  axillary,  is  concave  in  outline,  with  the  edge  obtuse 
near  the  digitations,  but  subacute  more  proximally.  The  supposed  hinder  border  evidently 
articulated  with  another  bone,  probably  the  hypoplastron,  out  nearly  to  the  digitated  border, 
thus  abolishing  the  fontanel.  The  greater  part  of  the  inferior  surface  of  the  bone  is  orna- 
mented with  anastamosing  ridges  and  some  tubercles,  about  three  or  four  of  them  lying  along 
a  line  20  mm.  long. 

Genus  SYLLOMUS  Cope. 

Costal  bones  suturally  articulated  with  the  peripherals.  Surface  of  carapace  sculptured 
with  grooves  and  ridges.  Humerus  much  flattened  distally.  Ectepicondylar  passage  a  com- 
plete foramen.    Radial  process  remote  from  head  of  bone. 

Type :    Syllomus  crispatus  Cope. 

Syllomus  crispatus  Cope. 
Plate  32,  figs.  I,  2;   teit-fig.  269. 
Syllomus  crispatus.  Cope,  Proc.  Amer.  Philos.  Soc,  xxxv,  1896,  p.  139.— Hay,  Bibliog.  and  Cat.  Foss. 

Vert.  N.  A.,  1902,  p.  442. 

The  remains  on  which  this  species  was  based  are  now  in  the  American  Museum  of  Natural 
History  and  bear  the  number  6134.  These  remains  consist  of  the  right  humerus,  lacking  only 
the  ulnar  process,  and  2  fragments  of  costals.  These  were  collected  by  Cope  in  Miocene 
deposits,  on  the  Pamunkey  River,  Virginia. 

The  first  fragment  of  costal  belongs  to  the  distal  end  of  the  bone  (plate  32,  fig.  i).  The 
width  at  the  end  is  47  mm.,  but  this  diminishes  proximally.  The  thickness  at  the  proximal 
end  of  the  fragment  is  6  mm.;  but  at  the  distal  end  this  has  become  only  2  mm.  This  border 
articulated  by  close  suture  with  the  contiguous  peripheral.  Doubtless  the  rib  passed  beyond 
the  border  and  entered  a  pit  in  the  peripheral.  The  surface  of  the  bone  is  sculptured  with 
anastomosing  grooves  and  ridges,  usually  parallel  with  the  long  axis  of  the  costal.  The  sculp- 
ture becomes  coarser  toward  the  proximal  end  of  the  bone.  Parallel  with  and  close  to  the 
peripheral  border  is  a  shallow  groove  which  may  be  a  portion  of  a  costo-peripheral  sulcus. 

The  other  fragment  of  costal  comes  from  near  the  neural  end  (plate  32,  fig.  2)  and  the 
width  is  45  mm.  It  is  crost  by  a  narrow,  but  sharp,  ridge,  which  indicates  that  the  carapace 
was  traverst  on  each  side  by  a  lateral  keel.  We  may  also  safely  assume  that  there  was  a  median 
keel  The  thickness  of  the  bone,  on  what  is  probably  the  proximal  side  of  the  keel,  is  7  mm. 
Toward  the  distal  end  the  thickness  diminishes.  The  surface  of  this  fragment  is  more  coarsely 
and  irregularly  sculptured  than  that  of  the  other  and  the  elevations  vary  more  in  size  and  form. 
No  trace  of  sulci  appears  on  this  fragment.    A  portion  of  the  surface  is,  however,  destroyed. 


212 


KOSSH,    TURTLES    OF    NORTH    AMERICA. 


The  humerus  (fig.  269)  resembles  that  of  a  true  sea-turtle.  The  total  length  is  loomm.  The 
distal  end  is  broad  and  flat.  The  head  of  the  bone  is  elongated  reniform,  the  long  axis  being 
at  nearly  right  angles  with  the  plane  of  the  distal  end.     Its  long  diameter  is  32  mm.;    the 

shorter,  17  mm.  The  ulnar  process  is  broken  away, 
but  a  groove  separated  it  distinctly  from  the  head. 
The  radial  process  is  divided  into  two  portions;  one 
part  being  on  the  under  side  of  the  shaft,  40  mm. 
below  the  upper  border  of  the  head;  the  other  part 
on  the  radial  border,  still  further  down  on  the  shaft. 
Both  portions  are  prominent.  The  narrowest  part 
of  the  shaft  is  20  mm.  wide  and  1 1  mm.  thick.  The 
distal  end  is  41  mm.  wide.  The  ectepicondylar  pas- 
sage is  a  foramen.  It  emerges  on  the  lower  side 
of  the  bone  10  mm.  above  the  distal  extremity. 
The  condyles  are  distinctly  separated  from  the  sur- 
rounding bone.  Their  fore-and-aft  extent  is  22  mm. 
The  radial  epicondyle  is  broad,  thick,  and  flat;  the 
ulnar  little  prominent.  It  is  remarkable  that  Cope 
in  his  description  of  this  bone  regarded  the  anterior 
border  as  the  posterior. 

Genus  LEMBONAX  Cope. 

Fig.  26g.~Syllomus  cnspatus.    Right  Plastron  with  probably  a   fontanel   extending 

humerus      Type.     xi^.  from   the   entoplastron   to    the    xiphiplastra.      No 

„    ,  ,     ,  ,      ,  •  1     L      J-  .u    J        dieitations  of  bone  proceeding  from  the  plastral 

On  left,  the  ventral  surface;   on  right,  the  radial  border.  »  \,  t-    •    ,  r        i  i 

bones  toward  the  midUne.  Lpiplastrahrmly  sutured 
to  the  hyoplastra,  the  suture  oblique  to  the  midline;   the  xiphiplastra  similarly  joined  to  the 
hypoplastra,  the  suture  at  right  angles  with  the  midline. 
Type:  Lembonax  polemtcus  Cope. 

The  position  of  this  genus  is  very  problematical.  Cope  concluded  originally  that  the 
relationships  were  with  the  Chelydridx  rather  than  with  the  Cheloniidae.  At  a  later  time  he 
stated  (Amer.  Naturalist,  xvi,  1882,  p.  989)  that  not  enough  was  yet  known  to  assure  us  to 
what  family  the  genus  belonged,  except  that  they  were  not  Trionychidae.  Nothing  has  been 
added  to  our  knowledge  on  that  point  since  that  time.  Cope  referred  two  additional  species, 
L.  propylaus  and  L.  insularts,  to  the  genu?.  While  the  present  writer  retains  these  species 
in  this  genus  provisionally,  there  appears  to  be  no  evidence  whatever  that  they  belong  there. 

For  want  of  knowledge  where  Lembonax  polemtcus  belongs  it  is  here  referred  to  the 
Cheloniidae. 

Lembonax  polemicus  Cope. 

Fig.  270. 

Lembonax  polemicus,   CoPE,  f^xt.  Batrach.,  Reptilia,  Aves  N.  A.,   1870,  p.   168. — Hay,  Bibliog.    and 
Cat.  Foss.  Vert.  N.  A.,  1902,  p.  444. 

This  species  was  sent  to  Professor  Cope  from  the  Eocene  greensand  near  Farmingdale, 
Monmouth  County,  New  Jersey.  The  type  and  only  known  specimen  is  now  in  the  American 
Museum  of  Natural  History  and  bears  the  number  11 34.  It  furnishes  a  portion  of  the  plastron 
and  the  base  of  the  scapula.  The  materials  indicate  a  large  individual,  but  they  furnish 
meager  information  regarding  its  structure  and  relationships. 

The  most  important  parts  of  the  plastron  are  a  portion  of  the  right  hyoplastron  and  a 
portion  of  the  right  hypoplastron.     The  outer  borders  of  both  these  bones  are  wanting. 

The  hyoplastral  fragment  (fig.  270)  has  at  present  a  length  of  233  mm.,  having  apparently 
lost  a  slight  portion  since  it  was  studied  by  Cope.  The  greatest  width  is  136  mm.  The  thick- 
ness varies  from  10  to  15  mm.  Anteriorly  the  bone  terminates  at  the  union  with  the  epi- 
plastron.  Posteriorly,  there  is  no  indication  of  suture  with  the  hypoplastron,  and  this  may 
have  been  farther  away  than  indicated  in  the  figure.    The  inner  border  of  the  bone  is  thick, 


CHEI-ONIID^. 


213 


obtuse,  and  along  the  hinder  third  is  somewhat  dentated.  Anteriorly,  the  upper  surface  is 
furnisht  with  ridges  which  are  sharp  and  prominent  as  they  approach  the  free  inner  border, 
but  which  become  obsolete  in  the  opposite  direction.    These  ridges  seem  to  diverge  from  the 

anterior  buttress  of  the  hyoplastron  (fig.  270,  C),  if  such 
existed.  At  the  anterior  end  of  the  bone  the  inner  border 
turns  slightly  outward  and,  at  an  angle  of  about  75°,  meets 
the  sutural  border  for  articulation  with  the  epiplastron  (fig. 
270,  A  to  B).  These  bones  were  not  joined  by  squamosal 
suture,  as  they  are  in  the  Cheloniidx  and  the  Chelydridae, 
but  by  dentated  suture.  The  lower  surface  of  the  bone  is 
smooth  and  convex,  especially  transversely.  The  upper 
surface  is  concave.  At  the  anterior  end  of  the  bone,  on 
the  upper  surface,  190  mm.  behind  the  anterior  end  (fig. 
270,  C),  is  a  slight  elevation,  as  if  it  were  the  base  of  an 
axillary  buttress.  The  lower  surface  of  the  bone  just  behind 
this  point  also  indicates  that  the  plastron  rose  toward  the 
carapace. 

The  portion  of  hypoplastron  has  a  length  of  155  mm. 
and  a  width  of  125  mm.  Anteriorly  the  suture  for  the  hyo- 
plastron is  missing.  The  inner  border  is  subacute  and 
smooth,  thus  differing  from  the  corresponding  border  of  the 
hyoplastron.  The  suture  for  the  xiphiplastron  runs  at  right 
angles  with  the  midline.  It  shows  that  the  two  bones  were 
firmly  united  by  coarse  interdigitating  teeth.  Toward  the 
outer  border  the  bone  has  a  thickness  of  about  13  mm., 
but  this  diminishes  slowly  toward  the  inner  border.  As  the 
outer  border  is  approacht,  the  bone  begins  to  ascend  in  a 
decided  manner,  as  if  approaching  the  carapace  (fig.  270, 
/)).  If  this  conclusion  is  correct,  as  indicated  by  both  hyo- 
plastron and  hypoplastron,  these  bones  were,  relatively  to 
their  length,  very  narrow;  and  there  is  indicated  a  wide  fonta- 
nel, that  extended  from  the  entoplastron  to  the  xiphiplastra. 
It  seems  improbable  that  the  inner  borders  came  into  close 
proximity.  There  were  certainly  no  digitations  extending 
from  the  hyoplastron  and  hypoplastron  toward  the  mid- 
line, as  there  are  in  the  Cheloniidx  and  the  Chelydrids. 
A  fragment  of  bone  present  indicates  that  the  hyohypo- 
plastral  suture  was  formed  by  the  interdigitation  of  finer 
processes  than  that  of  the  hypoxiphiplastral  suture.  On  the  anterior  end  of  the  fragment  of 
hypoplastron  there  are  traces  of  this  suture,  so  that  this  bone  appears  to  have  had  a  fore- 
and-aft  extent  of  about  170  mm. 

The  fragment  of  scapula  present  was  that  of  a  very  large  turtle.  It  is  possible  that  it  did 
not  belong  to  the  same  individual  as  the  plastral  bones.  The  long  diameter  of  the  neck  of 
the  bone  is  98  mm.;  the  short  diameter,  42  mm. 


Fig.  270. — Lembon a X  polemicus. 
Portion  of  plastron.  Type.  X}. 
No.  1134  A.  M.  N.  H. 

A  to  B,  border  for  articulation  with  the  epi- 
plastron ;  C,  base  of  axillary  buttress ; 
D,  probable  base  of  inguinal  buttress ; 
hya,  hyoplastron;    hypo,  hypoplastron. 


Lembonax?  insularis  Cope. 
Fig.  271. 


16. — Hay,  Bibliog.  and  Cat.  Kos.s. 


Lembonax  insularis.  Cope,  Proc.  Acad.  Nat.  Sci.  Phila.   1872,  p. 

Vert.  N.  A.,   1902,  p.  444- 

Professor  Cope's  materials  representing  this  species  were  meager  and  his  descriptions  of 
it  unsatisfactory.  Nor  have  the  means  for  increasing  our  knowledge  of  it  been  augmented; 
they  have  even  been  reduced.  In  the  American  Museum  of  Natural  History  there  is  a  lot  of 
bones  labeled  by  Cope  as  the  type  of  his  Lembonax  insularis,  and  bearing  the  museum  s 
number  2347.  This  lot  came  to  Cope  from  the  Eocene  bed  of  greensand  at  Vincentown 
Burlington  County,  New  Jersey.     Cope  stated  that  the  species  was  based  on  nuchal  and 


214 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


peripheral  bones ;  but  he  also  exprest  doubt  whether  these  bones  might  not  rather  belong 
to  the  rear  of  the  carapace.  Among  the  bones  in  the  lot  mentioned  there  is  none  that  can  be 
recognized  as  a  bone  belonging  in  the  midline.  Fragments  are  found  which,  when  fitted 
together,  furnish  fig.  271.  The  bone  markt  by  I  is  certainly  that  called  by  Cope  the  first 
marginal.  It  seems  impossible  to  determine  just  where  it  belonged.  It  is,  for  various  reasons, 
improbable  that  it  belonged  in  front.  Hence,  assuming  that  Cope  had  a  symmetrical  bone 
which  joined  the  supposed  first  peripheral,  the  latter  is  here  taken  to  belong  behind  and  to 
be  the  last  left  peripheral. 

Cope  estimated  the  length  of  the  bone  i  to  be  153  mm.  It  is  not  known  whether  he  took 
account  of  the  narrow  fragment  on  the  right  of  the  figure;    but  there  is  no  doubt  that  this 

fragment  belongs  where  it  is  placed. 
The  length  of  the  bone  then,  not  includ- 
ing a  deeper  plate  on  the  right  that 
would  be  hidden  when  the  bone  joined 
the  one  next  to  it,  is  165  mm.  The 
greatest  width,  omitting  a  deep  sutural 
plate,  is  100  mm.  The  thickness  on  the 
right  side  is  27  mm.  The  greatest  thick- 
ness is  to  the  left  of  the  middle  of  the 
length  and  is  45  mm.  Cope  states  that 
this  is  the  thickness  nearthesutureof  the 
second  peripheral;  from  which  expres- 
sion we  may  infer  that  the  narrow  frag- 
ment on  the  left  of  the  figure,  markt  2, 
is  a  part  of  the  penultimate  peripheral. 
The  free  border  of  the  bone  I,  so  far  as 
represented,  is  thick  and  obtuse.  Fig. 
Fig.  271.— Lembortax  insularis.     Fragments  of  two  bones  -^  ^  stciwn  from  a  to  b.    The  free 

of  the  carapace,  with  section  of  one.     Type.     X  J.  ^^^^^^  ^^  ^^^^  ^^^^^^^  ^^^  left, projected 

a  to  b,  direction  of  section,     i,  probable  last  peripheral;  in  an  obtUSe  angle.      It  appears  improb- 

2,  probable  penultimate  peripheral.  ^j^,^     ^^^^     ^^^^     ^^     irregular     border 

would  be  found  on  the  front  of  the  carapace.  The  upper  surface  is  convex  and  undulating, 
but  there  is  no  definite  sculpture.     Toward  the  free  border  the  surface  is  pitted  and  rough. 

Seen  from  below  the  bone  is  concave.  Near  the  hinder  border  of  the  narrow  fragment  on 
the  right  is  a  prominent  ridge.  A  suspicion  is  awakened  that  this  is  the  fragment  which  Cope 
mentions  as  bearing  the  support  of  a  vertebra.  The  ridge  mentioned  continues  for  some 
distance  on  the  larger  part  of  the  bone  of  which  the  fragment  is  a  part.  Behind  it,  on  the 
larger  fragment,  are  two  equally  prominent  ridges,  followed  by  some  smaller  ones,  and  these 
are  separated  by  deep  grooves.  What  is  the  meaning  of  these  grooves  and  ridges  can  not  be 
determined.  It  is  possible  that  the  median  bone,  whether  nuchal  or  pygal,  sent  a  process 
along  the  under  surface  of  the  bone  i,  two-thirds  its  length. 

The  bone  shown  on  the  left  of  the  one  indicated  by  i  has  a  thickness  of  33  mm.;  and  it 
is  possible  that  this  is  a  part  of  what  Cope  called  the  nuchal.  In  that  case  the  bone  i  would 
be  either  the  right  ultimate  peripheral,  or  first  left  peripheral. 

As  in  the  case  of  L.?  propylaus,  it  is  impossible  to  state  with  certainty  that  this  species 
belongs  to  the  genus  Lembonax. 

Lembonax?  propylaeus  Cope. 
Fig.  272. 

Lembonax  propylceus.  Cope,  Proc.  Acad.  Nat.  Sci.,  Phila.  1872,  p.  15. 
Lembonax  prophylaus.  Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  444. 

The  type  of  this  species  is  now  in  the  American  Museum  of  Natural  History,  and  has 
received  the  number  13 10.  This  specimen  was  found  in  the  Eocene  greensand,  in  the  vicinity 
of  Farmingdale,  Monmouth  County,  New  Jersey,  the  same  formation  and  locality  that  furnisht 
the  type  of  the  genus,  L.  polcmicus. 


CHELONIlDiE. 


215 


The  type  specimen  (fig.  272),  all  that  is  known  of  the  species,  consists  of  a  nuchal  bone,  a 
considerable  part  of  the  first  left  peripheral,  and  a  fragment  of  the  right. 

The  species  is  remarkable  on  account  of  the  great  excavation  in  the  front  of  the  nuchal, 
reminding  us  of  that  of  the  nuchal  of  Allopleuron  hoffmani  (Gray).  The  individual  was  a 
large  one,  the  distance  between  the  extremities  of  the  nuchal  being  about  225  mm.  The  antero- 
posterior extent  of  the  bone,  at  the  midline,  is  105  mm.  The  thickness  on  the  midline  and  half- 
way between  the  fore  and  hinder  borders  is  25  mm.  The  anterior  border  is  subacute,  except 
toward  the  extremities,  where  it  becomes  thick  and  obtuse.  In  the  hinder  border  there  is  a 
notch  for  the  front  end  of  the  first  neural  bone. 

The  border  for  union  with  the  first  peripheral  is  beveled,  so  that  the  first  peripheral  some- 
what overlaps  the  nuchal.  The  suture  between  the  two  bones  is  a  coarse  one.  A  portion  of 
the  border  for  union  with  the  first  costal  presents  a  kind  of  tongue-and-groove  joint,  there  being 
on  the  edge  of  the  nuchal  2  grooves  and  3  slightly  projecting  laminae. 

The  upper  surface  of  the  bone  is  smooth  and  there  are  no  traces  seen  of  the  presence  of 
sulci.    On  the  under  side  of  the  bone,  there  is,  on  the  midline  near  the  hinder  border,  an  eleva- 


FlG    272 — Lembonax  propylicus.     Nuchal  and  portions  of  right  and  left  first  peripherals. 

Type.      Xi 

tion  that  probably  furnisht  an  articulation  for  the  neural  spine  of  the  first  dorsal  vertebra. 
There  is  no  surface  for  articulation  with  the  last  cervical,  such  as  is  found  in   the  living 

Cheloniidae. 

Cope  referred  this  species  unqualifiedly  to  the  genus  Lembonax  and  stated  that  it  threw 
much  light  on  the  character  of  the  genus.  As  there  are  no  carapacial  bones  accompanying  the 
type  of  L.  polemicus  and  no  plastral  bones  accompanying  the  type  of  his  L.  propylceus,  it  is 
difficult  to  understand  why  they  should  be  so  confidently  referred  to  the  same  genus.  On  the 
other  hand,  it  is  possible  that  both  types  belong  to  the  same  species. 

Genus  PROCOLPOCHELYS  nov. 

An  imperfectly  known  genus  of  Cheloniidae.  Shell  large,  with  thick  and  heavy  neurals  and 
costals;  two  or  three  pairs  of  costals  articulating  each  with  3  neurals.  The  neurals  probably 
exceeding  8  in  number.  First  costal  plate  of  each  side  suturally  articulated  with  the  nuchal 
and  the  first  peripheral;  its  rib-end  entering  pit  in  third  peripheral.  Large  fontanels  between 
the  costals  and  all  the  peripherals  behind  the  first. 

Type:    Chelonta  grandteva  Leidy. 

The  known  materials  of  the  type  of  this  genus  lack  much  of  yielding  a  satisfactory  knowl- 
edge of  the  characters  of  the  genus.  Nevertheless,  it  seems  evident  that  Leidy's  species  does 
not  belong  to  the  same  genus  as  Chelonia  mydas.  Cope  referred  the  species  to  his  genus 
Puppigerus;  but,  inasmuch  as  Lydekker  in  1889  (Cat.  Foss.  Reptilia,  m,  p.  52)  made  Chelonc 


2l6 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


longiceps  the  type  of  Puppigerus,  and  the  latter  is  not  congeneric  with  Chelonia  grandava,  this 
species  can  not  be  placed  under  Piippigerus. 

A  study  of  the  known  materials  of  Chelonia  grandceva  makes  it  apparent  that  the  first 
costal  bone  was  articulated  with  the  nuchal  and  the  first  peripheral  of  each  side  and  that  some 
of  the  costals  were  articulated  proximally  with  3  neurals  each.  In  these  respects  the  species 
differs  from  any  belonging  to  either  Chelonia,  Eretmochelys,  or  Caretta. 

As  regards  the  relations  of  the  costals  to  the  neurals,  we  find  similar  conditions  in  a  spec- 
imen of  Colpochelys  kempi  in  the  American  Museum  of  Natural  History.  In  this  there  are 
apparently  13  neurals,  and  the  costals  of  the  third,  fourth,  fifth  and  sixth  pairs  articulate  each 
with  3  of  these  neurals.  Nevertheless,  nearly  all  the  neurals  are  hexagonal,  none  octagonal, 
as  in  Testudo,  where  some  costals  articulate  with  3  neurals. 

On  a  comparison  of  the  widths  of  the  costals  with  the  lengths  of  the  neurals  we  find  a 
confirmation  of  the  conclusion  that  there  were,  as  in  Colpochelys,  more  than  8  neurals. 

But  while  agreeing  with  Colpochelys  in  these  respects  Procolpochelys  differs  from  it  in 
another.  In  Colpochelys  the  end  of  the  rib  of  the  first  costal  bone  enters  a  pit  in  the  fourth 
or  fifth  peripheral,  while  in  Procolpochelys  grandceva,  as  in  most  Cheloniidae,  the  end  of  the 
first  costal  rib  enters  a  pit  in  the  third  peripheral. 

Procolpochelys  is  therefore  distinguisht  from  all  the  hitherto  recognized  genera  ot  Che- 
loniidae. 

On  pages  8,  9,  and  10  Colpochelys  kempt  has  been  referredj  to  [the]  genus  Lepidochelys. 


Figs.  273  and  274. — Procolpochelys  grandteva.     Neurals.      X'j. 
273.  Two  neural  bones.    Type.  274.  Neural.    No.  1027  A.  M.  N.  H. 

Procolpochelys  grandaeva  (Leidy). 
Figs.  273-280. 

Chelonia  grandteva,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.,  v,  1851,  p.  329;  Ibid.,  viii,  1856,  p.  303. — 
Cope,  Cook's  Gaol.  New  Jersey,  1868  (1869),  p.  738;  Ext.  Batrach.,  Reptilia,  and  Aves  N.  A., 
1870,  p.  153,  figs.  40,  41. — Maack,  Palaeontographica,  xviii,  1869,  p.  283. 

Puppigerus  grandievus.  Cope,  Ext.  Batrach.,  etc.,  1870,  p.  235;  Proc.  Amer.  Philos.  Soc,  xiv,  1875,  P- 
363. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  443. 

Dr.  Leidy's  Chelonia  grandceva  is  an  insufficiently  known  species.  The  type  belongs  to 
the  Philadelphia  Academy.  It  consists  of  three  neural  bones  which  had  been  found  in  what 
is  regarded  as  Miocene  marl,  in  Salem  County,  New  Jersey.  One  of  these  neurals  appeared 
to  Leidy  to  be  the  first.  A  portion  of  the  anterior  end  had  been  broken  off,  yet  the  part 
that  remained  was  67  mm.  long  and  48  mm.  wide.  The  other  two  neurals  were  hexagonal, 
as  wide  as  long  or  wider,  and  each  had  a  posterior  process,  showing  that  some  of  the  neurals 
were  sharply  notcht  in  front.  One  of  these  (fig.  273,  a)  was  54  mm.  long,  67  mm.  wide,  and 
15.5  mm.  thick;  the  other  (fig.  273, i)  was  58  mm.  long,  including  the  process,  and  58  mm.  wide. 

Cope,  in  1870,  as  cited,  further  described  the  species.  He  had  some  fragments  of  costals; 
a  fragment  of  probably  the  nuchal;  the  scapula,  which  he  figured;  and  what  he  described  as 
the  femur,  but  which  was  evidently  the  humerus,  as  indeed  he  says  it  was  in  his  explanation 


CHELONIID^.  217 

of  the  figures  on  page  ii.  These  came  from  Shiloh,  Cumberland  County,  New  Jersey.  These 
specimens  are  now  in  the  American  Museum  and  have  the  number  1319.  The  scapula  re- 
sembles that  of  Caretta,  except  that  the  upper  end  is  more  flattened.  The  humerus  is  now 
missing  from  this  lot  of  bones.  The  radial  process  is  stated  to  have  been  on  the  shaft  some 
distance  below  the  head.  The  costal  plate  is  82  mm.  wide  and  13  mm.  thick.  This  and  other 
fragments  of  the  costals  show  that  these  bones  were  not  suturally  joined  to  the  peripherals; 
but  also  that  there  was  no  considerable  interval  between  them,  the  projection  of  the  rib  being 
short.  With  this  lot  is  the  "nuchal  or  marginal  vertebral"  mentioned  by  Cope.  It  appears  to 
be  the  left  end  of  the  nuchal.  The  thickness  at  the  median  end  of  the  fragment  is  15  mm., 
that  near  the  junction  with  the  first  costal,  21  mm.  The  first  peripheral  sent  a  thin  process  for 
some  distance  beneath  the  nuchal,  near  the  anterior  border. 

Cope  mentions  another  specimen,  belonging  to  the  Philadelphia  Academy,  which  presented 
4  peripherals  and  a  fragment  of  a  hypoplastral.  A  peripheral,  believed  to  be  the  third,  had  a 
length  of  about  47  mm.,  and  a  width  of  21  mm.  Cope  concluded  that  the  rib  of  the  first  costal 
did  not  run  parallel  with  the  hinder  border  of  the  costal,  but  approacht  the  hinder  border 
toward  the  distal  end.  Another  peripheral  belonging  near  the  middle  of  the  series  was  trigonal 
in  section,  measuring  59  mm.  across  the  lower  face  and  45  mm.  across  the  inner,  or  visceral, 
face.  This  and  two  other  peripherals  were  emarginate  at  the  middle  of  the  outer  border.  The 
dermal  sulcus  crost  the  peripherals  a  little  behind  the  middle. 

In  the  American  Museum  of  Natural  History  is  a  lot  of  fragments  labeled  by  Cope 
as  belonging  to  this  species.  The  catalog  number  is  1027;  the  locality  uncertain,  but  probably 
in  New  Jersey.  A  neural  appears  to  confirm  Cope's  determination.  This  neural  (fig.  274)  is 
63  mm.  long,  in  the  midline  of  the  upper  surface  and  including  the  process.  The  width  is 
71  mm.;  the  thickness,  16  mm.  The  anterior  border  is  beveled  so  that  the  neural  was  overlapt 
somewhat  by  the  preceding  neural;  and  the  hinder  border  similarly  overlapt  the  succeeding 
one.  A  peripheral,  probably  the  second,  is  85  mm.  long,  47  mm.  wide  at  the  middle  of  the 
length,  and  20  mm.  thick.  The  outer  border  is  obtuse;  the  inner,  acute  (fig.  275).  Frag- 
ments of  three  other  peripherals  belonged  probably  near  the  rear  of  the  carapace;  at  least, 
they  have  a  much  narrower  visceral  face  than  those  described  by  Cope.  One  has  the  upper 
and  lower  faces  48  mm.  wide;  the  inner  face  only  19  mm.  The  other  bones  throw  little 
or  no  additional  light  on  the  species. 

In  the  paleontological  collection  at  Princeton  University  is  a  lot  of  turtle  bones  that  are 
labeled  as  having  been  received  in  December,  1879,  from  Mr.  George  Erety  Shoemaker,  now 
of  Philadelphia.  This  gentleman  writes  that  these  remains  came  from  a  marl  bed  near  Shiloh, 
Cumberland  County,  New  Jersey.  This  marl  belongs  to  the  Miocene.  While  there  is  a  large 
amount  of  this  material,  it  unfortunately  consists  of  the  remains  of  at  least  four  turtles,  belong- 
ing apparently  to  2  genera.  It  has  been  found  impracticable  to  separate  these  satisfactorily, 
but  apparently  there  are  parts  of  3  individuals  of  the  present  species. 

With  these  bones  are  2  neurals  which,  it  can  hardly  be  doubted,  belong  to  P.  grandccva. 
One  of  these  is  50  mm.  long,  with  a  short  posterior  spine,  48  mm.  wide,  and  12  mm.  thick. 
To  it  is  attacht  the  neural  arch.  Another,  a  more  posterior  and  smaller  one,  is  32  mm.  long 
and  44  mm.  wide.  Two  other  neurals  present  are  only  8  mm.  thick  and  evidently  belong  to 
a  quite  different  turtle. 

There  are  in  the  lot,  belonging  apparently  to  P.  grandava,  at  least  five  proximal  ends  of 
costals,  and  most  of  these  show  that  they  articulated  each  with  three  neurals,  of  which  the 
median  one  was  the  smaller.  These  costals  vary  in  width  from  80  mm.  to  105  mm.  and  in 
thickness  from  10  mm.  to  14  mm.  The  rib-heads  were  large.  Besides  the  proximal  ends  of 
costals,  there  are  many  other  portions  of  these  bones.  A  part  of  a  right  first  costal  requires 
description.  The  proximal  end  is  missing.  Near  the  distal  end  the  width  is  no  mm.;  the 
thickness  12  mm.  The  anterior  border  articulated  with  the  nuchal  and  with  the  first  periph- 
eral, the  two  sutural  borders  making  between  them  an  angle  of  about  135°.  The  remainder 
of  the  distal  border,  65  mm.,  was  free  from  the  adjacent  peripheral,  the  second.  Near  the 
hinder  border  issues  the  rib,  making  its  way  to  the  pit  in  the  third  peripheral.  Only  a  portion 
of  the  second  costal  has  been  recognized.  Another  costal,  prob^-bly  the  fourth,  is  represented 
by  the  distal  two-thirds.  The  distal  end  is  133  mm.  wide;  the  other  extremity,  \  1 1  mm.  The 
thickness,  at  a  distance  of  85  mm.  above  the  free  border,  is  18  mm.;   but  at  the  proximal  end 


2l8 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


oi"  the  fragment,  only  12  mm.  The  sutures  are  very  jagged.  Nearer  one  sutural  border  a 
sulcus  descends,  which  separated  two  costal  scutes.  Two  other  costals  measure  each  72  mm.  in 
width  at  the  distal  end.     In  all  these  the  free  end  of  the  rib  projected  beyond  the  distal  border. 

A  nuchal  is  represented  by  the  greater  part  including  the  entire  front.  There  was  an 
articular  tuberosity  for  the  eighth  cervical;  the  anterior  border  of  this  bone  was  200  mm. 
long.  It  is  excavated  somewhat  for  the  neck  and  head.  The  upper  surface  is  quite  convex 
from  side  to  side.  Antero-posteriorly  the  bone  measures  96  mm.  The  front  border  is  obtuse; 
behind  it  a  short  distance  the  thickness  is  16  mm.,  increasing  at  the  ends  of  the  bone  to  20  mm. 
The  hinder  border  joined  suturally  the  first  costal  bone. 

The  first  left  peripheral  is  connected  with  the  nuchal.  It  is  1 10  mm.  long  and  80  mm. 
wide.  The  hinder  border  articulated  with  the  first  costal.  The  free  border  is  obtuse  and  the 
distal  end  is  18  mm.  thick.  There  is  present  the  proximal  end  of  another  left  first  peripheral 
which  is  considerably  thicker  than  the  one  just  described. 

What  are  evidently  right  and  left  second  peripherals,  of  an  individual  smaller  than  either 
of  the  above,  are  present.  The  proximal  end  of  the  one  of  the  left  side  is  65  mm.  wide,  whereas 
the  distal  end  of  the  left  first,  described  above,  is  72  mm.  wide;    besides,  the  two  do  not  fit 


Figs.  275-280. — Procolpochelys  grand<eva.     Various  peripherals.      X§. 

275.  Section  across  middle  of  supposed  second  peripheral;   free  border  toward 

right.    No.  1027  A.M.N.  H. 

276.  Section  at  anterior  end  of  second  peripheral.    Princeton  Univ.  Coll. 

277.  Section  near  hinder  end  of  third  peripheral.    Princeton  Univ.  Coll. 

278.  Section  near  front  end  of  supposed  fifth  peripheral.     Princeton  Univ.  Coll. 

279.  Right  hinder  peripheral,  view  above.    Princeton  Univ.  Coll. 

280.  Upper  surface  of  supposed  eleventh  peripheral.    Princeton  Univ.  Coll. 

together  as  they  should  if  they  belonged  to  the  same  individual.  No  differences  are  seen 
that  indicate  different  species.  This  second  peripheral  (fig.  276)  is  95  mm.  long,  64  mm. 
wide  and  22  mm.  thick  proximally;  51  mm.  wide  and  25  mm.  thick  distally.  The  anterior 
border  is  obtuse,  the  hinder  acute  and  with  suture  for  a  costal.  The  succeeding,  or  third, 
peripherals  are  joined  to  those  just  described.  They  measure  about  95  mm.  along  the  free 
border  and  are  70  mm.  wide  at  the  distal  end.  A  ridge  that  begins  on  the  inferior  surface  of 
the  second  becomes  more  conspicuous  near  the  outer  border  of  the  anterior  half  of  the  third; 
and  just  above  it,  near  the  front  of  the  bone,  is  the  pit  for  the  rib  of  the  first  costal.  Fig.  277 
is  a  section  at  the  hinder  end  of  this  peripheral. 

There  are  present  nineteen  peripherals,  not  counting  the  part  of  a  first  which  belongs  to 
the  larger  individual.     At  least  three  are  not  at  all  represented;    but  at  least  two  that  are 


CHELONIID^.  219 

present  on  one  side  are  not  represented  by  their  fellows  of  the  opposite  side.  There  is  therefore 
both  a  redundancy  and  a  shortage.  Evidently  neither  fourth  peripheral  is  present.  There 
are  representatives  of  3  peripherals,  probably  the  fifth,  sixth,  and  seventh  of  the  left  side. 
The  supposed  fifth  (fig.  278)  is  99  mm.  long  and  consists  of  two  plates  which  meet  each  other 
at  an  acute  free  border.  The  two  succeeding  this,  the  sixth  and  the  seventh,  are  damaged, 
but  the  faces  make  a  smaller  angle  with  each  other.  The  fifth  presents  an  extremely  shallow 
rib-pit,  located  in  the  hinder  half  of  the  length.  It  is  highly  probable  that  these  peripherals 
belong  to  a  turtle  of  some  other  genus. 

On  the  left  side  are  three  peripherals  following  in  their  natural  order.  Each  of  these 
has  three  faces,  a  somewhat  convex  upper  face,  a  flat  lower  face,  and  a  channeled  visceral 
face.  The  rib-pit  of  the  first  one  is  a  little  behind  the  middle  of  the  length.  This  bone 
resembles  one  in  lot  number  2215,  of  the  American  Museum  mentioned  above;  but  both  sides 
of  the  latter  are  flat.  The  bone  under  description  is  125  mm.  long,  64  mm.  wide  in  front,  and 
22  mm.  thick.  The  next  one  is  a  very  little  shorter  and  slightly  narrower.  It  presents  no  pit. 
This  is  in  the  front  end  of  the  next  peripheral,  close  to  the  suture.  This  next  bone  is  1 15  mm. 
long,  46  mm.  wide  anteriorly  and  21  mm.  thick.  In  general,  the  section  of  it  resembles  that 
of  the  first  of  the  three  here  described.  Bones  corresponding  to  the  second  and  third  of  those 
just  described  appear  to  be  represented  on  the  right  side  of  the  animal.  On  this  side  the  pit 
which  was  in  the  front  end  of  this  third  of  the  side  is  moved  forward  to  the  left  junction  between 
the  two  bones.  On  this  side,  too,  the  hinder  of  the  two  is  broken,  but  both  ends  of  it  appear 
to  be  present.  Following  what  almost  certainly  is  its  hinder  end  is  a  similar  peripheral,  with 
its  hinder  end  missing.  This  bone  has  a  small  pit  for  a  rib.  The  inner,  or  visceral  face,  is  21 
mm.  wide. 

Besides  these  peripherals  there  are  four  others  present  which  require  consideration.  Two 
of  these  are  corresponding  bones  of  opposite  sides.  Fig.  279  represents  the  one  taken  to 
belong  to  the  right  side.  It  will  be  observed  that  there  is  a  decided  change  in  the  direction 
of  the  curve  at  the  supposed  anterior  end.  This  bone  is  88  mm.  long  and  48  mm.  wide  at  the 
sulcus.  On  its  channeled  inner  face,  at  the  end  of  the  sulcus,  is  a  deep  pit  for  a  rib.  A  portion 
of  another  peripheral  is  attacht  to  what  is  supposed  to  be  the  anterior  end  of  this  curved 
peripheral.    Its  inner  face  is  narrower. 

The  curved  peripheral  of  the  other  side  has,  at  some  period  of  life,  had  the  supposed 
anterior  end  damaged,  so  that  it  has  the  appearance  of  having  formed  a  false  joint  with  its 
contiguous  peripheral.  Attacht  to  the  hinder  end  of  this  bone  is  another  peripheral  (fig.  280) 
whose  fellow  is  not  present.  It  is  105  mm.  long.  The  inner  face  is  channeled  but  there  is 
no  pit.  One  end,  supposed  to  be  the  posterior,  is  narrow — only  24  mm.  wide.  It  is  probable 
that  this  bone  is  the  eleventh  and  that  the  narrow  end  joined  the  pygal. 

To  add  to  the  difficulties,  there  is  present  what  appears  to  be  the  left  half  of  a  pygal  bone. 
This  was  86  mm.  wide  and  65  mm.  high.  It  articulated  suturally  with  a  suprapygal  and 
laterally  by  its  whole  height  with  the  contiguous  peripherals,  the  eleventh  pair;  but  certainly 
not  with  the  one  regarded  above  as  the  eleventh. 

Portions  of  a  large  thick  plastron  are  present.  One  piece  may  be  part  of  a  hyoplastron. 
A  free  border,  probably  the  outer,  is  digitated.  One  border  articulated  suturally  with  another 
bone,  supposedly  the  hypoplastron. 

On  the  nuchal  bone  the  sulcus  bounding  posteriorly  the  nuchal  scute  or  the  first  marginal 
is  44  mm.  behind  the  free  border,  near  the  midline  and  54  mm.  from  the  border  at  the  outer 
end  of  the  bone.  The  limits  of  the  nuchal  scute  can  not  be  made  out.  On  the  first  and  second 
peripherals  the  costo-marginal  sulcus  is  seen  running  nearer  the  costal  margins  of  the  bones 
than  the  free  margins.  Posterior  to  these  the  costo-marginal  sulci  doubtless  lay  on  the  mtervals 
between  the  costal  and  peripheral  bones.  Each  peripheral  is  crost  by  a  sulcus  separatmg 
two  marginals. 

The  outer  surfaces  of  all  the  bones  are  smooth,  except  that  they  are  markt  by  numerous 
vascular  grooves. 

In  the  paleontological  collection  at  Rutgers  College,  New  Brunswick,  New  Jersey,  are 
found  one  peripheral  and  one  complete  costal  which  are  labeled  as  belonging  to  this  species 
and  as  having  come  from  the  Miocene  marl  at  Tinton  Falls.  There  is  probably  an  error  in 
the  locality. 


220  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

The  peripheral  appears  to  be  the  second  of  the  series.  Its  length  is  Ii6  mm.;  its  greatest 
width,  66  mm.;  and  the  thickness,  22  mm.  This  is  reduced  gradually  to  the  acute  hinder 
border.    The  anterior  border  is  obtuse. 

The  length  of"  the  costal,  omitting  the  portion  of  the  rib  projecting  from  the  peripheral 
border,  is  220  mm.  The  width  is  87  mm.;  the  thickness  1 1  mm.  at  the  proximal  end,  14  mm. 
distally.  Proximally  the  costal  articulated  with  3  peripherals,  as  we  have  found  to  be  the  case 
with  some  of  the  costals  of  the  Princeton  specimen.  The  middle  and  smallest  of  these  neurals 
was  crost  by  a  sulcus  which  divided  two  vertebral  scutes.  This  sulcus  is  36  mm.  long  on  the 
costal,  a  fact  that  indicates  that  the  vertebral  scutes  were  not  wide. 

The  surface  of  the  bone  is  smooth,  but  markt  by  vascular  grooves.  The  distal  border  was 
not  articulated  to  the  peripherals,  except  by  gomphosis  of  the  end  ot  the  rib. 

Genus  CHELONIA  Brongniart. 

Cheloniidae  with  persisting  costo-peripheral  fontanels;  four  pairs  of  costal  scutes;  jaws  not 
hookt;  the  grinding-surface  of  each  maxilla  with  a  prominent  tuberculated  ridge  which 
terminates  in  front  in  a  sharp  tooth  and  which  does  not  extend  on  the  narrow  premaxilla. 
Limbs  each  usually  with  a  single  claw. 

Type:    Chelonia  mydas  (Linnaeus). 

To  this  genus  there  is  assigned,  with  doubt,  a  single  species  of  North  American  fossil 
turtles.  It  is  that  called  by  Cope  Puppigerus  parvitectus.  In  the  writer's  Bibliography  and 
Catalogue,  1902,  p.  443,  this  species  and  Leidy's  Chelonia  grandxva  were  catalogged  under 
the  genus  Puppigerus;  and  he  would  be  glad  to  retain  them  there  were  it  possible.  In  that 
work  it  was  stated  that  the  type  oi  Puppigerus  was  Leidy's  Chelonia  grandceva;  but  the  fact 
was  overlookt  that  Mr.  Richard  Lydekker  had,  in  1889,  chosen  as  the  type  of  that  genus  Owen's 
Chelone  longiceps.  According  to  Lydekker,  Puppigerus  becomes  a  synonym  o{  Lytoloma  Cope. 
It  is  possible  that  such  is  the  case;  but  it  appears  more  probable  that  Puppigerus  is  a  distinct 
genus,  with  P.  longiceps  as  its  type.  The  writer  can  not  believe  that  Leidy's  C.  grandccva 
is  congeneric  with  P.  longiceps  and  he  has  for  that  reason  proposed  for  C.  grandccva  the  generic 
name  Procolpochelys.  Furthermore  it  is  improbable  that  parvitecta  belongs  in  the  same  genus 
as  Leidy's  grandccva. 

About  the  only  reasons  for  placing  the  species  parvitecta  under  Chelonia  are  that  we  thus 
avoid  erecting  a  new  genus  on  extremely  insufficient  materials  and  that  we  return  the  species 
to  the  genus  to  which  it  was  originally  referred,  which  genus  is  probably  not  far  from  the  true 
one  yet  to  be  establisht. 

On  page  143  of  the  Proceedings  of  the  Philadelphia  Academy  for  1867,  Cope  described 
fragments  of  what  he  regarded  as  two  species  of  Chelone;  but  he  applied  no  specific  names  to 
these.  In  the  Miocene  volume  of  the  Maryland  Geological  Survey,  1904,  page  63,  Case  has 
copied  Cope's  descriptions.  Case  has  also  described  and  figured  (op.  cit.,  p.  64,  plate  xxvi, 
fig.  5)  the  proximal  portion  of  a  scapula  which  he  refers  to  an  unnamed  species  of  Chelone. 
This,  as  well  as  Cope's  specimens,  was  found  in  the  Calvert  formation  of  the  Miocene.  These 
remains  are  not  generically  determinable. 

Chelonia?  parvitecta  Cope. 
Plate  32,  fig.  3. 

Chelone  parvitecta.  Cope,  Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1870,  p.  155. 

Chelone  parviscuttim,  CoPE,  Cook's  Geol.  New  Jersey,  1868  (1869),  p.  738. 

Chelone  parviscutatus,  CoPE,  Amer.  Jour.  Sci.  (2),  I,  1870,  p.  138. 

Puppigerus?  parviscutum,  CoPE,  Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1870,  p.  235,  244. 

Puppigerus  parvitecta,  CoPE,  Proc.  Acad.  Nat.  Sci.,  1872,  p.  15. 

Puppigerus  parvitectus.  Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  443. 

The  present  species,  whose  specific  name  has  been  so  greatly  abused,  has  as  its  type  a 
single  costal  plate,  which  is  now  in  the  American  Museum  of  Natural  History  and  bears  the 
number  1318.  It  was  found  at  Squankum,  Monmouth  County,  New  Jersey,  and  was  supposed 
by  Cope  to  have  come  from  the  Miocene  marl;  but  this  is  Lower  Eocene.  He  reported  having 
found  another  costal  in  Charles  County,  Maryland. 


CHELONIID^.  221 

The  costal  here  described  (plate  32,  fig.  3)  appears  to  have  been  the  sixth  of  the  right  side, 
and  to  have  belonged  to  an  individual  whose  carapace  had  a  length  of  about  400  mm.  The 
length  of  the  bone,  from  the  neural  border  to  the  distal  end,  is  125  mm.  The  width  at  the 
middle  of  the  length  is  44  mm.  The  thickness  at  the  sutural  border  is  5  mm.  The  rib  adds 
about  3  mm.  through  the  middle  of  the  width.  The  distal  end  of  the  bone  is  cut  off  obliquely 
and  the  margin  is  smooth,  showing  that  there  were  costo-peripheral  fontanels  and  no  suture 
with  the  peripheral. 

On  the  proximal  end  of  the  upper  surface  appears  a  portion  of  a  vertebral  scute,  probably 
the  fourth.  The  outer  angle  is  distant  45  mm.  from  the  neural  border  and  the  angle  is  less  than 
90°.  The  sulcus  between  the  third  and  the  fourth  costal  scutes  runs  on  the  bone  near  the 
posterior  border. 

The  upper  surface  of  the  bone  is  markt  by  numerous  vascular  grooves.  In  general,  these 
run  toward  the  distal  end,  branching  and  anastamosing.  When  followed  toward  the  proximal 
end  they  soon  enter  the  bone.  In  the  area  of  the  vertebral  scute  the  surface  is  pitted  by  vascular 
openings.  The  anterior  border  of  the  bone  is  grooved  somewhat  at  right  angles  with  the 
sutural  edge. 

Family  CHELYDRID^  Agassiz. 

Plastron  loosely  joined  to  the  carapace;  consisting  of  nine  elements  and  considerably 
reduced.  The  entoplastron  T-shaped;  the  bridge  narrow.  Nuchal  bone  with  long  costiform 
processes.  A  full  series  of  neurals.  Skull  with  temporal  region  incompletely  rooft  over;  the 
postfrontal  bones  large.  Quadrate  notcht  for  passage  of  the  stapedial  rod.  Crushing-surfaces 
without  ridges  and  processes.    Caudal  vertebrae  mostly  opisthoccelous. 

At  the  present  day  this  family  is  represented  by  3  genera,  Chelydra  and  Macrochelys  of 
North  America  and  Devisia  of  New  Guinea.  The  first  contains  two  species ;  Macrochelys 
and  Devisia  only  one  each.  Chelydra  serpentina  is  the  best-known  species  and  ranges  east 
of  the  Rocky  Mountains  from  Canada  to  Ecuador. 

The  members  of  this  family  are  regarded  as  being  among  the  most  primitive  of  the  living 
turtles.  Nevertheless,  known  remains  of  the  family  have  not  been  found  in  deposits  earlier 
than  the  Upper  Ohgocene.  Chelydra  murchisoni  is  found  in  the  Upper  Miocene  ol  Switzer- 
land and  C.  decheni  in  the  Upper  Oligocene  of  the  Rhine  region,  near  Bonn. 

While  the  Chelydridae  are  in  many  respects  primitive  in  their  structure,  in  other  respects 
they  have  deviated  considerably  from  their  Amphichelydian  ancestors.  The  roof  of  the  tem- 
poral region  has  suffered  considerable  reduction.  The  plastron  has  undergone  reduction. 
The  writer  can  not  believe  that  the  opisthoccelous  caudal  vertebrae  are  primitive.  The  costi- 
form processes  of  the  nuchal  are  a  late  acquisition. 

As  the  writer  has  stated  elsewhere,  he  holds  that  the  Chelydridae  are  related  to  the  Chelo- 
niida  through  some  Cretaceous  ancestor  of  Toxochelys.  Altho  he  has  indicated  (Bull.  Amer. 
Mus.  Nat.  Hist.,  xxi,  1905,  p.  167)  that  the  Emydidae  and  the  Testudinidae  sprang  from  the 
Chelydridae  he  is  now  inclined  to  hold  that  they  had  their  origin  from  the  Dermatemydidae. 

Genus  ACHERONTEMYS  Hay. 

A  genus  of  Chelydridae.  Carapace  broad,  considerably  deprest.  Neural,  bones  eight, 
about  as  broad  as  long,  mostly  hexagonal,  with  the  broader  end  forward.  A  single  broad 
suprapygal.  Peripherals,  1 1  pairs,  placed  opposite  the  ends  of  their  respective  costals.  Verte- 
bral scutes  very  broad. 

Type:     Acherontemys  heckmani  Hay. 

The  relationships  of  the  present  genus  are  yet  somewhat  uncertain,  but  they  are  believed 
to  be  with  the  Chelydridje.  A  comparison  of  the  plan  of  the  carapace  of  the  species  described 
below  with  those  of  the  carapaces  of  Chelydra  and  Macrochelys  (Boulenger's  Cat.  Chelonians, 
pp.  22,  24)  will  show  that  there  are  great'  resemblances.  The  nuchal  bone  has  not  the  back- 
ward extension  seen  in  the  Emydidae.  The  peripherals  do  not  alternate  with  the  costals. 
Acherontemys  differs  from  the  living  genera  mentioned  in  having  the  costals  more  closely 
articulated  with  the  peripherals  and  in  possessing  extremely  broad  vertebral  scutes. 


222 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


Fig.  281. — Acherontemys  heckmani. 
Carapace  of  type.      X^. 


Acherontemys  heckmani  Hay. 

Fig.  281. 

Acherontemys  heckmani.  Hay,  Proc.  U.  S.  Nat.  Mus.  xxil,  1899,  P-  23,  plate  vi ;   Bibliog.  and  Cat.  Foss. 
Vert.  N.  A.,  1902,  p.  446. 

The  type  ot  the  present  species  belongs  to  the  U.  S. 
National  Museum.  It  was  found  near  Roslyn,  State  of 
Washington,  in  what  is  known  as  the  Roslyn  sandstone, 
of  the  Miocene  formation. 

The  carapace  (figure  281)  is  broad  and  must  have 
been  rather  deprest.  There  are  no  evidences  of  serrations 
on  the  hinder  border  of  the  carapace.  The  length  is 
181  mm.;  the  width,  118  mm.  The  median  line  appears 
to  have  a  sort  of  keel,  with  low  bosses.  The  sutures 
between  the  bones  are  distinct.  There  are  8  neurals.  The 
first  is  nearly  square;  the  eighth  pentagonal  and  elon- 
gated; the  others  hexagonal.  The  nuchal  is  about  twice 
as  wide  as  long.  The  peripherals  are  nearly  square,  and 
those  at  the  sides  are  placed  opposite  the  ends  of  their 
respective  costals. 

The  sulci  are  distinctly  imprest.    The  region  of  the 

nuchal  scute  is  damaged.    The  vertebrals  are  extremely 

broad.    The  first  has  a  width  of  75  mm.;    the  second, 

90  mm.;    the  third,  85  mm.;    the  fourth,  75  mm.;    the 

fifth,  65  mm.     The  costal  scutes  are  correspondingly  diminisht  in  transverse  extent.     The 

first,  fourth,  and  fifth  vertebrals  are  short.     In  the  case  of  the  fourth  this  is  caused  by  the 

crossing  of  the  sulcus  between  it  and  the  third  on  the  sixth,  instead  of  on  the  fifth  neural. 

Nothing  is  known  regarding  the  plastron  of  this  species. 

Genus  MACROCHELYS  Gray. 

Three  or  four  additional,  or  supramarginal,  scutes  on  each  side.     Orbits  lateral.     Tail 
with  small  scales  inferiorly  (Boulenger). 
Type:    Macrochelys  temmincki  (Troost). 

This  genus  is  represented  in  the  living  fauna  by  the  alHgator  snapper,  a  magnificent 
turtle  that  lives  in  the  lower  Mississippi  River  region.  It  reaches  a  large  size  and  has  a  dis- 
proportionately large  head. 

Macrochelys  iloridana  sp.  nov. 
Figs.  181-285. 
Macrochelys  floriJana,  Hay,  Bull.  Amer.  Mus.  Nat.  Hist,  xxiii,  1907,  p.  847,  figs.  I-4. 

Four  peripheral  bones  of  perhaps  as  many  individuals,  a  portion  of  the  Jarman  collection 
in  Vanderbilt  University,  indicate  a  hitherto  undescribed  species  of  alligator  snapper.  It  was 
found  in  what  are  probably  Peace  Creek  beds,  Hillsboro  County,  Florida. 

A  fourth  left  peripheral  (fig.  282)  is  46  mm.  long,  34  mm.  high,  and  21  mm.  thick.  The 
upper  and  lower  faces  are  of  moderate  convexity  and  meet  in  a  subacute  free  border.  At  the 
hinder  end  of  the  bone  is  an  excavation  for  a  process  of  the  hyoplastron,  occupying  nearly 
half  the  length  of  the  bone. 

The  right  seventh  peripheral  (figs.  283,  284)  is  60  mm.  long,  50  mm.  high,  and  25  mm. 
thick.  The  upper  border  was  articulated  to  the  costal  by  a  jagged  suture.  The  slightly  convex 
upper  and  lower  faces  meet  to  form  an  acute  free  border.  As  in  M.  temmincki,  there  is  a 
long  excavation  for  the  hypoplastron. 

The  ninth  peripheral  (fig.  285)  has  in  the  free  border  a  notch  and  is  tootht  both  in  front 
and  behind  this  notch.    In  M.  temmincki  there  is  a  single  tooth,  the  one  in  front  of  the  notch. 

This  species  differs  from  the  living  M.  temmincki  in  having  the  free  border  of  the  fourth 
peripheral  far  less  acute,  the  upper  face  more  convex,  the  rib-pit  nearer  the  hinder  end  of  the 


CHELYDRID^.  223 

bone,  and  no  excavation  for  the  hyoplastron;  also  in  having  the  free  border  of  the  seventh 
peripheral  much  more  obtuse  and  the  upper  border  not  in  sutural  contact  with  the  costal; 
further,  in  having  a  single  process  on  the  free  border  of  the  ninth  peripheral. 


284. 


Figs.  282-285. — Macrochelys  foriduna.     Peripherals  of  type.      Xj. 

282.  Fourth  left  peripheral,  with  section  across  middle  of  length. 

283.  Seventh  right  peripheral  seen  from  above,  with  section  across  middle  of  length. 

284.  Seventh  right  peripheral  seen  from  below. 

285.  Ninth  right  peripheral  seen  from  above,  with  section  near  hinder  end. 

Genus  CHELYDRA  Schweigger. 

No  supramarginal  scutes.  Orbit  directed  outward  and  upward.  Tail  with  large  scutes 
inferiorly  (Boulenger). 

This  genus  is  represented  in  North  America,  in  a  fossil  state,  only  by  the  following  species. 
Cope's  Chelydra  crassa  will  be  described  under  the  genus  Hoplochelys. 

Chelydra  serpentina  Linnsus. 

Testudo  serpentina,  LlNN.«us,  Syst.  Nat.,  ed.  X,  1858,  p.  199. 

Chelydra  serpentina,   Schweigger,   Prod.,  1814,   p.  23. — Boulenger,  Cat.  Chelonians,  1889,  p.  20, 
figs.  3,  4. 

Cope  (Extinct  Batrachia,  Reptilia  and  Aves  of  North  America  1869,  p.  125)  reports 
briefly  that  Samuel  R.  Harrison,  of  Easton,  Maryland,  had  found  remains  of  this  species  in 
Pleistocene  deposits  at  Oxford  Neck,  Talbot  County,  Maryland.  They  were  accompanied 
by  bones  of  Elephas  amencanus,  Cervus  canadensis,  Cariacus  virgintanius,  and  Terrapene 
eurypygia. 

FamUy  DERMATEMYDID.a;  Gray. 

Plastron  in  most  cases  suturally  articulated  to  the  carapace;  with  an  entoplastron,  but 
without  mesoplastra;  the  anterior  and  posterior  lobes  usually  reduced  in  size.  Nuchal  bone 
with  or  without  costiform  processes.  Neural  bones  reduced  in  number,  except  in  Baptemys; 
some  of  the  hinder  costal  bones  meeting  their  fellows  in  the  midline,  except  in  the  same  genus. 
Peripheral  bones  in  10  or  11  pairs.  Plastron  furnisht  with  a  full  series  of  inframarginal 
scutes,  except  in  Basilemys.  The  scutes  of  the  anterior  lobe  perhaps  in  all  cases  modified 
from  the  condition  seen  in  Baina.  Caudal  vertebrae  in  all  the  known  forms  procoelous.  The 
hinder  lobe  of  the  plastron  often  with  a  scar  for  the  pelvis,  but  the  latter  never  suturally  joined 
to  the  plastron.  Temporal  region  not  rooft  over  and  no  parieto-squamosal  arch.  Quadrate 
notcht  behind  for  the  stapedial  rod. 


224 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


So  far  as  the  writer  can  determine,  there  is  no  good  reason  for  separating  the  fossil  genera 
that  have  been  arranged  under  the  name  Adocidce  from  the  Hving  dermatemyds.  The  name 
Dermatemydie  was  employed  by  Gray  in  1870,  apparently  a  short  time  before  Cope  pro- 
posed the  name  Adocidce,  and  ought,  under  the  form  Dermatemydida:,  to  be  used  for  the  family. 
It  is  difficult  to  frame  a  definition  of  the  family.  Our  knowledge  of  the  few  living  forms 
is  not  complete.  Of  the  great  mass  of  the  fossil  genera  we  are  acquainted  with  little  more 
than  the  shells,  and  often  with  only  small  portions  of  these.  Of  no  fossil  genus  have  we  the 
skull,  except  that  of  Baptemys.  The  limbs  and  feet  and  the  caudal  vertebrae  are  unknown. 
In  the  shells  there  is  a  great  variety  of  structure.  Perhaps  no  other  family  furnishes  so  many 
deviations  from  what  is  regarded  as  the  normal  condition  in  turtles. 

Usually  in  the  members  of  this  family  some  of  the  hinder  neurals  are  aborted,  a  condition 
that  permits  one  or  more  pairs  of  the  hinder  costals  to  meet  their  fellows  in  the  midline.  In 
Baptemys,  however,  there  is  a  full  series  of  neurals.  In  the  living  genera,  Staurotypus  and 
Claudius,  the  nuchal  bone  has  long  costiform  processes,  and  the  possession  of  these  has  been 
regarded  as  a  characteristic  of  the  family;  but  these  processes  are  absent  in  Der.tiatemys ; 
while  in  Adocus  and  Xenochelys,  and  perhaps  others,  they  are  short;  in  Anosteira  they  are 
absent.     The  plastral  lobes  are  in  nearly  all  cases  shortened  and  often  narrowed.      In  the 

living  Dermatemys  (fig.  286)  the  lobes  are  quite 
well  developt.  In  nearly  all  forms  the  plastron 
is  suturally  articulated  with  the  carapace;  but 
in  living  Claudius  the  union  is  ligamentous. 
In  some  of  the  fossil  genera  the  sutures  are 
coarse,  forming  a  transition  from  the  ligamen- 
tous connection  to  the  closely  knit  sutures. 
In  Adocus  and  Baptemys  axillary  and  inguinal 
buttresses  rise  to  the  costals,  or  nearly  so.  In 
probably  all  genera,  except  Basilemys,  there 
is  a  series  of  inframarginal  scutes  crossing  the 
bridge.  In  Xenochelys  and  Staurotypus  the 
number  is  reduced  to  two.  In  probably  all 
genera  there  is  some  deviation  in  the  arrange- 
ment of  the  scutes  of  the  anterior  lobe  from  the 
arrangement  seen  in  such  a  primitive  turtle  as 
Ba'ena.  In  Adocus  and  some  others,  this  pro- 
ceeds no  further  than  the  great  development  of 
the  intergulars,  by  virtue  of  which  the  gulars 
are  greatly  reduced  and  pushed  far  from  each 


Fig.  286. — Dermatemys  mawi.     Carapace  and 
plastron.     After  Boulenger. 

infm  I,  etc.,  inframarginal  scutes. 


Other.  If  this  should  in  any  cases  have  proceeded  to  the  entire  suppression  of  the  gulars, 
the  usurping  intergulars  would  be  mistaken  for  the  abolisht  scutes.  Undoubtedly,  in  some 
cases,  there  has  occurred  either  a  coalescence  or  a  suppression  of  scutes.  In  Baptemys 
ivyomingensis  there  are  only  5  pairs  on  the  plastron,  excepting  the  inframarginals.  Two  pairs 
occupy  the  area  covered  in  Adocus  by  the  intergulars,  gulars,  humerals,  and  pectorals. 
The  pectorals  appear  to  have  advanct  so  as  partly  to  cover  the  epiplastrals.  Three  pairs  of 
scutes  ought  to  be  found  in  front  of  this;  but  there  is  only  one  pair.  In  B.  tricarinata,  there 
are  apparently  distinct  evidences  of  a  sulcus  crossing  the  front  of  the  entoplastron  and  the 
middle  of  each  epiplastron.  This  probably  bounds  the  humerals  in  front.  It  seems  probable 
that  the  area  in  front  of  this  sulcus  is  occupied  by  the  intergulars  and  that  the  gulars  have 
been  extirpated. 

The  plastral  scutes  of  Agomphus  appear  to  be  arranged  like  those  of  Baptemys. 

In  Xenochehs  we  find  the  modifications  of  the  plastral  scutes  to  have  gone  still  further. 
On  each  bridge  there  are  only  2  scutes.  What  we  must  regard  as  the  intergulars  have  coalesct 
into  a  single  scute.  This  is  followed  by  a  scute  on  each  side  which  does  not  come  to  the  mid- 
line. The  whole  area  extending  from  these  to  the  femoral  scutes  is  occupied  by  a  single  pair 
of  scutes.  The  pair  of  scutes  following  the  intergular  may  be  gulars,  but  it  appears  more 
probable  that  the  pectorals  have  advanct  still  further  forward  than  in  Baptemys  and  have 


DERMATEMYDID^. 


225 


Geological  Distribution  of  the  Genera  of 
Dermatemydida. 


Formations. 

Genera. 

Recent 

Dermatemys,  Staurotypus,  Claudius. 

Pleistocene 

Oligocene 

Xenochelys,  Anosteira  ? 

Anosteira,  Baptemys,  FPseudotrionyi, 
Kallistira,    Notomorpha,    Alamos-  ■ 
cmys,  Hoplochelys. 

Upper  Cretaceous 

Adocus,  Homorophus,   Zygoramma, 
Agomphus,  Compsemys,  Basilemys. 

crowded  the  humerals  against  the  intergulars  into  the  place  of  the  supprest  gulars.     Then 
the  pectorals  and  the  abdominals  have  coalesct. 

In  Anosteira  apparently  the  plastral  scutes  were  so  delicate  that  they  left  no  impressions 
of  the  sulci  on  the  bones. 

Usually  there  are  no  striking  modifications  of  the  scutes  of  the  carapace;  but  attention 
may  be  called  to  those  of  Xenochelys,  and  more  especially  to  those  of  Anosteira. 

As  regards  the  geological  continuance  of  the  family,  we  find  the  earliest  form,  Basilemys, 
in  the  Judith  River  beds  and  three  genera  exist  to-day.  All  together  sixteen  genera  are  here 
recognized,  and  these  have  the  geological  distribution  presented  in  the  accompanying  table. 

Pseudotrionyx  has  been  described  from  the 
Bruxellian  of  Belgium  by  Dr.  Louis  Dollo. 
There  can  be  no  doubt  that  it  is  related  to  Anos- 
teira of  America.  The  Bruxellian  beds  are  equiv- 
alents of  our  Wind  River  deposits.  Anosteira 
anglica  has  been  described  from  the  Lower  Oli- 
gocene of  Hordwell,  England.  The  character  of 
the  sculpture  and  the  straightness  of  the  hypo- 
xiphiplastral  suture  suggest  a  closer  relationship 
with  Pseudotrionyx  than  with  Anosteira.  Like 
Anosteira,  Pseudotrionyx  probably  had  only  10 
pairs  of  peripherals. 

We  know  nothing  about  the  history  of  the 
Dermatemydidae  prior  to  the  Upper  Cretaceous. 
Tretosternon  Owen,  of  the  Wealden,  suggests 
strongly  the  genus  Adocus;  but  the  skull  is  said 
by  Dollo  {Peltochclys  duchastclii.  Bull.  Mus.  roy. 
d'hist.  nat.,  Belgique,  ill,  1884,  p.  79)  to  have 
the  temporal  region  protected  by  a  bony  roof.  It  is  easy  to  conjecture  that  some  form  similar 
to  Tretosternon  was  the  Jurassic  ancestor  of  the  Dermatemydidae,  which  during  the  Upper 
Cretaceous  times  evolved  into  so  many  genera  and  species. 

As  already  stated,  Pseudotrionyx  of  the  Middle  Eocene  is  evidently  related  to  the  Derma- 
temydidae. It  is  believed  to  be  related  also  to  Carettochelys  insculpta,  a  species  living  in  the 
Fly  River,  New  Guinea.  Happily,  our  knowledge  of  this  species  has  been  increast  by  the 
description  of  a  better  specimen  than  either  of  those  previously  known.  This  description  is 
given  by  Mr.  Edgar  R.  Waite  in  the  Records  of  the  Australian  Museum,  vi,  1905,  pp.  i  lo-i  18, 
and  is  illustrated  by  four  plates  and  three  text-figures.  Baur  regarded  this  turtle  as  belonging 
among  the  Trionychidae,  but  as  being  closely  akin  to  Pseudotrionyx  and  exhibiting  connections 
with  the  Dermatemydidae.  Waite  shows  that  the  turtle  is  a  true  Cryptodiran  nearest  to  the 
Dermatemydidae,  but  also  as  connecting  the  Cryptodira  with  the  Trionychidae.  The  animal 
is  certainly  a  Cryptodire,  but  not  a  dermatemyd.  It  belongs  to  a  family  near  the  Derma- 
temydidae. Probably  Pseudotrionyx  belonged  to  the  same  family;  and  a  comparison  of  the 
figures  of  the  shell  with  those  of  Dollo's  Peltochelys  duchastellii  (Bull.  Mus.  roy.  Hist.  Nat., 
Belgique,  iii,  1884,  p.  78,  plate  II)  shows  many  striking  resemblances.  Waite  states  that 
the  quadrate  is  not  completely  closed  behind,  but  that  there  is  a  posterior  notch,  wide  but  not 
deeply  cleft.  On  the  other  hand  his  figure  (op.  cit.,  plate  xxvi,  fig.  3)  appears  to  show  dis- 
tinctly that  the  stapes  entered  the  tympanic  cavity  by  a  hole  in  the  quadrate,  just  as  it  does 
in  Trionyx.  If  this  conclusion  is  correct,  this  differentiates  the  family  from  the  Derma- 
temydidae;  as  does  also  the  wide  separation  of  the  pterygoids  by  the  palatines  and  the  basi- 

sphenoid.  ij       1  u 

It  seems  not  unreasonable  to  suppose  that  from  the  Dermatemydidx  there  sprang  the 
Emydidae  and  the  Chelydridae.  From  the  least  differentiated  Dermatemydidae,  as  Adocus, 
the  Emydidae  differ  especially  in  the  lack  of  intergulars  and  inframarginals;  but  both  these 
series  of  scutes  might  cease  to  be  developt.  In  one  of  the  earliest  of  the  Dermatemydidae 
there  are  no  inframarginals,  except  at  the  axillary  and  inguinal  notches.  Were  it  not  for  the 
intergulars  and  the  extraordinary  sculpture  of  Basilemys  we  might  regard  it  as  an  h-myd. 


»5 


226  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

Key  to  the  American  Genera  of  Fossil  Dermatemydid^. 

/i.  Upper  Cretaceous  genera. 

a'.  No  inframarginals,  coarsely  sculptured  with  pits,  furrows  and  pyramidal  elevations      Basilemys 

a^.  Sculpture  fine  and  granular Compsemys 

a'.  Sculpture  consisting  of  shallow  pits.     Borders  of  carapace  acute-edged.     Plastron 
rounded  in  front  and  behind,  with  full  set  of  plastral  scutes.     Hinder  marginal 

scutes  rising  well  on  the  costal  bones Adocus 

a*.  Like  Adocus,  but  with  axillary  and  inguinal  buttresses  and  costals  sending  long 

rib-heads  into  the  peripherals.    Bones  thin Zygoramma 

a^.  Shell  thick  and  heavy;    the  free  borders  of  carapace  thick  and  obtuse.     Hinder 

marginal  scutes  rising  little  or  not  at  all  on  the  costal  bones Agomphus 

a°.  Vertebral  scutes  said  to  be  usually  narrower  than  the  neural  bones Homorophus 

A  A.  Tertiary  genera. 

a',  hike  Adocus,  but  hinder  marginal  scutes  not  rising  on  costal  bones.    Tor.'^jon..  .  Alamosemys 

a^.  See  A.  a^  above.    Hinder  lobe  of  plastron  pointed.    Midway Agomphus 

a'.  Shell  thick;  free  borders  acute;  three  ridges  along  back;  the  plastron  rather  loosely 

joined  to  carapace.    No  inguinal  buttresses.    Torrejon Hoplochelys 

a*.  Like  Hoplochelys,   but  without  inguinal  buttresses.     Wasatch Kallistira 

a'.  Not  well  known.    At  least  the  anterior  peripherals  obtuse.    Wasatch Notomorpha 

a°.  A  full  set  of  neurals.     Carapace  smooth,  with  a  median  carina  on  rear  of  cara- 
pace.    Plastron  sutured  to  carapace.     Wasatch,  Wind  River,  and  Bridger.  .  .  .       Baptemys 
a'.  Shell  finely  sculptured.     Plastron  much  reduced  and  loosely  joined  to  the  carapace. 

Bridger Anosteira 

a*.  Shell  smooth;   no  buttresses;   five  pairs  plastral  scutes.    Oligocene Xenochelys 

Genus  BASILEMYS  Hay. 

Shell  highly  sculptured.  Epiplastra  much  thickened.  Bridge  wide.  Intergular  scutes 
present.  Pectorals  greatly  expanded  at  the  midline,  narrowed  laterally.  An  axillary  and  an 
inguinal  scute  but  no  other  inframarginals. 

Type:    Compsemys  variolosus  Cope. 

This  genus  differs  from  other  known  genera  of  Dermatemydidae  in  having  no  infra- 
marginals, except  the  axillary  and  the  inguinal. 

Basilemys  variolosa  (Cope). 
Plate  T,i,  fig.  4;  plate  34,  fig.  i;  text-fig.  287. 

?Compsemys  ogmius.  Cope,  Vert.  Cret.  Form.  West,  1875,  pp.  91,  261;    Proc.  Acad.  Nat.  Sci.  Phila. 

1875,  p.  9;    Brit.  N.  A.  Bound.  Surv.,  Report  on  Geol.  and  Resources  1875,  p.  336. 
Compsemys  variolosus.  Cope,  Proc.  Acad.  Nat.  Sci.  Phila.  1876,  p.  257;   Bull.  U.  S.  Geol.  Surv.  Terrs., 

m,  1877,  p.  573. 
Adocus  variolosus,  Lambe,  Ottawa  Naturalist,  XV,  1901,  p.  63,  plates  iii-vi;    Cont.  Canad.  Palaeont., 

II  (4to),  p.  39,  plate  ii,  text-figs.  4-6. 
Basilemys  variolosus,  Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  445. 
Adocus  (Basilemys)  variolosus,  OsBORN,  Cont.  Canad.  Palxont.,  Ill  (4to),  1902,  pp.  12,  16. 
Basilemys  ogmius.  Hatcher,  Bull.  U.  S.  Geol.  Surv.  No.  257,  1905,  p.  76. 

The  type  of  the  present  species  consists  of  nearly  the  whole  of  the  plastron,  various  periph- 
eral bones,  and  two  imperfect  costal  plates.  These  are  now  in  the  American  Museum  of 
Natural  History,  and  bear  the  catalog  number  1465.  This  type,  with  fragments  of  other 
individuals,  was  collected  for  Professor  Cope,  in  1876,  by  Mr.  Charles  H.  Sternberg,  in  the 
Judith  River  beds  of  Montana.  Since  that  time  other  specimens  of  the  species  have  been 
collected  by  members  of  the  Geological  Survey  of  Canada,  in  Judith  River  deposits,  just 
north  of  the  United  States  boundary  line  and  east  of  the  Rocky  Mountain  range.  More 
accurately,  the  remains  were  taken  on  Mackay  Creek,  along  Old  Man  River,  and  on  Red 
Deer  River. 

Fig.  287  is  reproduced  mostly  from  Cope's  type,  but  it  is  probable  that  the  fragment  of 
bone  around  the  axillary  notch  and  the  piece  of  epiplastron  do  not  belong  to  the  same  indi- 
vidual as  the  remainder  of  the  specimen,  these  anterior  pieces  being  somewhat  larger  than  we 


DERMATEMYDIDj^. 


227 


might  expect.  The  diagrammatic  figure  has  been  constructed  partly  from  the  type  and 
partly  from  materials  belonging  to  the  Canadian  Survey. 

This  species  was  a  large  one,  and  it  is  distinguisht  by  a  rather  remarkable  form  of  orna- 
mentation. The  length  of  the  plastron  of  the  type  was  not  far  from  670  mm.  and  the  total 
length  of  the  carapace  approximated  775  mm.  The  form  and  the  elevation  probably  resembled 
closely  those  of  the  species  oi  Adocus.  The  sculpture  seems  to  be  an  exaggerated  development 
of  that  of  the  genus  just  mentioned.  It  resembles  considerably  that  of  some  species  of  the 
Trionychidae,  but  the  pits  are  more  commonly  arranged  in  rows,  and  the  intervening  ridges 
are  more  acute.  Often  where  three  ridges  meet,  there  is  formed  a  sharp  trihedral  elevation. 
The  effect  is  to  produce  a  very  rough  surface.     There  are  usually  about  three  rows  of  pits 

in  10  mm.  The  whole  shell  is  covered  with  this  sculp- 
ture. It  is  best  developt  on  the  upper  and  lower  surfaces 
of  the  anterior  and  posterior  peripherals.  On  the  upper 
halves  of  the  peripherals  of  the  bridge  it  may  be  obscure. 
So  also  sometimes  on  parts  of  the  plastron,  as  in  the  case 
of  the  specimen  in  the  collection  of  the  Canadian  Survey. 
The  bridge  of  the  plastron  is  very  wide  antero-pos- 
teriorly,  the  anterior  and  posterior  lobes  relatively  short. 
The  rims  of  the  lobes  are  much  thickened,  the  interior 
portions  considerably  thinner.  The  epiplastron  of  the 
Canadian  specimen  (plate  32,  fig.  4),  which  was  about 
as  large  as  Cope's  more  complete  specimen,  is  38  mm. 
thick  near  its  union  with  its  fellow.  This  thickness 
diminishes  toward  the  axillary  notch,  where  it  is  28  mm. 
Behind  the  entoplastron  it  is  only  15  mm.  or  even  less. 
The  epiplastron  of  Cope's  material  has  an  extreme  thick- 
ness of  5 1  mm.  The  hyoplastral  and  hypoplastral  bones 
are  only  10  mm.  thick  where  they  join.  At  the  inguinal 
notch  the  rim  of  the  hinder  lobe  is  40  mm.  thick.  This 
gradually  diminishes  to  12  mm.  near  the  midline  behind. 
The  anterior  lobe  is  about  325  mm.  wide  and  144 
mm.  long,  measured  from  a  line  joining  the  two  axillary 
notches.  Its  sides  slope  forward  to  a  rather  blunt  point. 
The  lateral  face  of  the  thickened  rim  stands  at  a  right 
angle  with  the  flat  lower  surface  of  this  lobe.  The  sculp- 
ture rises  on  this  face  and  extends  for  a  distance  on  the 
upper  surface. 

The  entoplastron  is  large,  being  about  160  mm.  wide, 
but  only  100  mm.  long.  It  is  hexagonal,  with  the  lateral 
borders  shortest. 

On  the  lower  surface  of  the  front  lobe  is  found  a 
half  of  plastron.  Xj.  Mostly  from  p^j^  ^f  j^^g^  intergulars  which  extend  backward  to  the 
No.  14.65  A.  M.  N.  H.  anterior  border  of  the  entoplastron  and  separate  widely 

the  reduced  gulars.  The  humero-pectoral  sulcus  is  at  first  directed  backward  from  the 
axillary  notch  for  about  50  mm.,  then  is  turned  WddenlyS'forward  and  inward  to  the  middle 
of  the  entoplastron. 

The  posterior  lobe  is  approximately  340  mm.  wide  and  only  160  mm.  long.  It  is  broadly 
rounded  behind.  On  the  upper  surface  of  this  lobe  is  a  large,  smooth  scar  which  marks  the 
point  of  attachment  of  the  pubis. 

The  pectoral  scutes  are  narrow  at  their  outer  ends.     The  abdominal  scutes  are  large. 
The  median  sulcus  pursues  a  very  irregular  course  from  the  front  to  the  rear  of  the  plastron. 
The  bridge  is  remarkably  wide,  being  about  360  mm.,  considerably  more  than  one-half 
of  the  length  of  the  plastron. 

Behind  the  axillary  notch  there  is  a  rather  short  and  wide  axillary  scute,  followed  by  the 
narrowed  lower  end  of  the  fourth  marginal.  The  fifth  marginal  is  likewise  narrow,  but  the 
sixth  is  greatly  expanded.    The  seventh  and  eighth  are  pointed  at  their  lower  ends.    There  is  a 


Fig.  287 


Right 


228  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

single  narrow  inguinal.  We  see,  therefore,  that,  excepting  the  axillary  and  the  inguinal  scutes, 
there  were  no  inframarginals.  This  conclusion  is  confirmed  by  the  more  complete  shell  of 
Rasilemys  sinuosa  Riggs. 

Of  the  elements  of  the  carapace  the  nuchal  is  unknown  and  but  little  is  known  of  the  neu- 
rals.  With  the  type  are  parts  of  2  costals.  One  of  these  appears  to  be  the  eighth  of  the  right 
side.  The  length  of  the  fragment  is  144  mm.;  its  width  was  at  least  56  mm.  At  the  middle 
of  the  width  the  thickness  is  13  mm.  The  borders  and  the  course  of  the  rib  on  the  inferior 
surface  show  that  the  costal  was  curved  backward  from  its  proximal  to  its  distal  end.  Not  far 
from  its  hinder  border  it  is  traverst  by  a  deep  dermal  sulcus.  The  position  of  the  other  costal 
fragment  can  not  be  determined. 

Of  the  peripherals  there  are  present  an  anterior  one,  probably  the  second,  the  lower  halves 
of  most  of  those  forming  the  bridge  on  the  right  side,  and  those  of  the  right  side  from  the 
inguinal  notch  to  the  pygal.  In  the  collection  of  the  Canadian  Survey  the  third  right  peripheral 
is  represented  by  the  portion  bounding  the  axillary  notch.  The  greater  part  of  the  pygal  is 
with  Cope's  type.  Therefore,  with  the  exception  of  the  nuchal,  one  anterior  peripheral,  and 
the  outer  halves  of  the  bridge  peripherals,  we  are  acquainted  with  the  whole  rim  of  the  carapace. 

The  anterior  peripherals  did  not  project  so  far  beyond  the  soft  parts  of  the  animal  as  did 
the  posterior.  The  supposed  second  projected  beyond  the  soft  skin  of  the  under  side  52  mm. 
Its  length  along  the  free  border  is  90  mm.  The  thickness  is  21  mm.  The  portion  which  articu- 
lated with  the  first  costal  is  missing.  The  upper  surface  of  the  bone  is  nearly  flat;  the  lower 
is  somewhat  convex;   the  free  border  is  acute. 

The  third  peripheral,  as  represented  by  the  Canadian  specimen,  has  the  thinner  portion 
which  articulated  with  the  first  costal  broken  away.  The  sutural  edge  which  joined  the  outer 
anterior  angle  of  the  hyoplastron  is  present.  On  the  anterior  end  of  the  outer  surface  is  a 
right-angled  ridge,  which  farther  forward  passes  into  the  sharp  free  border  of  the  carapace. 
Below  this  ridge  the  sculptured  surface  lookt  downward  toward  the  axillary  notch;  the  surface 
above  the  ridge  was  a  part  of  the  upper  surface  of  the  shell.  The  whole  length  of  the  bone  is 
about  90  mm.  and  its  greatest  thickness  is  38  mm. 

The  figure  shows  what  parts  of  the  various  bridge  peripherals  are  present.  Probably  just 
beyond  the  line  of  fracture  the  peripherals  curved  upward  to  join  the  lower  ends  of  the  costals. 
This  outer,  or  upper,  portion  of  these  bridge  peripherals  appears  to  be  represented  by  one  bone 
in  the  Cope  collection.  The  costal  margin  of  this  bone  was  about  18  mm.  thick  and  this 
border  is  nearly  straight.  The  length  of  this  peripheral  is  103  mm.  and  it  rises  at  least  1 10  mm. 
The  sculpture  of  the  outer  surface  is  not  so  coarse  as  on  most  of  the  bones. 

The  seventh  peripheral  (plate  34,  fig.  i),  the  one  entering  into  the  inguinal  notch,  is  thick 
and  heavy.  Its  length  is  82  mm.;  its  thickness  anteriorly,  44  mm.,  posteriorly,  20  mm.;  its 
height,  at  least  70  mm.  Its  free  border  is  rounded  in  the  middle  of  the  length,  becoming 
broader  and  flatter  anteriorly,  sharper  posteriorly.  The  figure  just  referred  to  shows  the 
details  of  the  sculpture.  The  next  four  peripherals  have  respectively  the  lengths  100  mm.,  87 
mm.,  62  mm.,  and  53  mm.  The  heights  vary  from  at  least  100  mm.  in  the  eighth  to  75  mm.  in 
the  eleventh.  The  upper  border  of  all  appears  to  be  broken  away,  but  the  suture  evidently  was 
near.  The  eighth,  ninth,  and  tenth  have  their  outer  surfaces  somewhat  concave  from  above 
downward,  so  that  these  have  a  slight  upward  flare.  A  fragment  of  the  pygal  has  on  it  the 
descending  sulcus,  thus  showing  that  the  bone  was  about  60  mm.  wide.  Its  free  border  is 
acute  and  the  bone  is  18  mm.  thick,  70  mm.  above  the  free  border. 

The  connection  of  the  costals  with  some  of  these  posterior  peripherals  is  interesting.  It  is 
well  shown  in  an  eighth  right  peripheral  in  the  Canadian  collection.  This  is  broken  so  as  to 
show  that  the  end  of  the  rib  beyond  the  costal  plate  extends  downward  into  the  substance  of 
the  peripheral  about  30  mm.,  forming  a  gomphosial  articulation.  No  such  articulation  is  seen 
in  the  bridge  peripheral  above  described. 

The  greater  portion  of  the  pygal  is  present  in  the  type  of  the  species.  It  had  a  length  of 
60  mm.  along  the  free  border  and  a  height  of  about  75  mm.  The  outer  surface  is  nearly  flat, 
the  inner  convex.    The  free  border  is  acute,  as  is  that  of  most  of  the  peripherals. 

So  far  as  can  be  determined,  the  sulci  between  the  costal  and  the  marginal  scutes  followed 
pretty  closely  the  sutures  between  the  costal  and  the  peripheral  plates.  No  sulci  are  found 
crossing  the  two  costal  plates  present.    On  the  eighth  and  ninth  peripherals  a  deeply  imprest 


DERMATEMYDID^. 


229 


sulcus  runs  an  irregular  course  across  the  upper  ends,  65  mm.  above  the  free  border,  then  rises 
and  does  not  appear  on  the  more  posterior  peripherals  and  pygal. 

Mr.  L.  M.  Lambe,  of  the  Canadian  Geological  Survey,  describes  (op.  cit.,  p.  40)  some 
conical,  rugose  bones  which  he  believes  belonged  on  the  tail  of  this  species. 

Cope  speaks  of  the  dermal  sulci  as  being  deeply  imprest.  This  is  true  of  many  of  them, 
especially  of  those  of  such  costals  as  are  known — the  anterior  plastral  sulci,  and  some  others; 
but  many  are  extremely  narrow  and  shallow,  and  are  difficult  to  follow  as  they  wander  over 
and  among  the  pits  and  ridges  of  the  sculpture. 

Compsemys  ogmius  was  based  on  a  fragment  of  what  Cope  regarded  as  a  costal  plate  and 
on  a  fragment  of  the  plastron.  These  were  never  figured.  They  were  obtained  in  the  Judith 
River  beds  by  Dr.  G.  M.  Dawson,  of  the  British  Boundary  Survey,  at  a  point  along  the  Milk 
River,  near  the  boundary  between  Assiniboia  and  Alberta.  These  fragments  are  now  at 
Ottawa.  An  examination  of  the  bone  identified  as  part  of  a  costal  shows  that  it  is  really  a  part 
of  a  bridge  peripheral,  and  that  it  possibly  belongs  to  Basilemys  variolosa.  The  fragment  is 
exceedingly  poor.  It  is  only  55  mm.  square  and  shows  only  a  small  area  of  the  sculpture,  the 
remainder  having  been  weathered  off.  Where  shown,  the  ornamentation  is  obscure.  The 
piece  of  plastron  is  93  mm.  long,  35  mm.  wide,  and  12  mm.  thick.  The  sculpture  is  nearly 
effaced  by  weathering.  While  these  bones  may  belong  to  B.  variolosa,  there  is  too  much 
doubt  regarding  them  to  permit  us  to  adopt  for  them  and  the  last-named  species  the  earlier 
name  ogmius.  Even  if  ogmius  were  a  species  distinct  from  variolosus,  it  is  doubtful  whether 
new  materials  could  be  identified  by  means  of  the  type. 

Cope's  assignment  of  the  species  described  above  to  the  genus  Compsemys  is  an  error. 
The  sculpture  of  the  latter  is  of  a  very  diflFerent  character  and  there  were  probably  infra- 
marginals. 


288. 


Figs.  288  and  289. — Basilemys  sinuosa.     Carapace  and  plastron.     Xi'i. 
288.  Carapace.  289.  Plastron. 


Basilemys  sinuosa  Riggs. 

Plate  33,  figs.  I,  2;  teit-figs.  288,  289. 

Basilemys  sinuosus,  Riggs,  Pubs.  Field  Columb.  Mus.,  Geol.  ser.,  11,  1906,  p.  249,  plates  Ixxvi,  ixxvii. 

The  fine  specimen  on  which  this  species  is  founded  was  collected  by  Dr.  E.  S.  Riggs,  of 
Field  Natural  History  Museum,  Chicago.  It  was  secured  in  the  Laramie  deposits  of  Chalk 
Buttes,  near  Powderville,  Custer  County,  Montana.  With  it  were  found  bones  of  Trueratops, 
Trachodon,  and  other  characteristic  Laramie  fossils.  The  shell  is  nearly  complete.  Of  the 
plastron  nothing  is  missing,  except  some  parts  of  the  bridge  peripherals.    Of  the  carapace 


230 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


Vertebral. 

Length. 

Width. 

loo 

160 

•45 

100 

165 

100 

I2S 

90 

140 

*3S 

some  portions  of  the  neurals  and  the  contiguous  borders  of  the  right  third  and  fourth  costal 
plates  are  wanting. 

The  carapace  (plate  33;  text-fig.  288)  is  deprest,  due  probably  in  some  degree  to  pressure. 
The  anterior  border  is  excavated  over  the  neck,  broadly  rounded  behind.  Behind  the  ingui- 
nal notches  the  borders  are  somewhat  flared  upward. 

The  length  of  the  carapace  from  the  bottom  of  the  notch  in  front  to  the  rear,  measured  in 
a  straight  line,  is  715  mm.;  the  breadth  is  very  close  to  585  mm.  The  anterior  notch  is  22  mm. 
deep.  The  free  border  in  this  notch  is  about  25  mm.  thick.  On  each  side  of  the  midline  the 
border  thins  rapidly  and  soon  forms  an  acute  edge,  which  continues  to  the  axillary  notch. 
Behind  the  inguinal  notches  the  free  edges  are  acute. 

The  nuchal  bone  measures  85  mm.  along  the  midline;  its  width  is  145  mm.  The  first 
neural  was  about  80  mm.  long  and  60  mm.  wide  behind.  The  second  neural  is  oval,  68  mm. 
long,  40  mm.  .wide.  The  third  is  broadest  in  front,  80  mm.  long,  50  mm.  wide.  The  fourth 
neural  is  wanting;  the  fifth  is  defective.  The  sixth  is  70  mm.  long,  50  mm.  wide.  The  seventh 
and  eighth  are  small  and  irregular  in  form.  There  is  a  small  first  suprapygal.  The  second 
is  bifurcate,  as  in  Testudo.     It  measures  along  the  midline  60  mm.;   its  lateral  extent  is  170 

mm.  The  third  suprapygal  is  72  mm.  along  the  midline  and  135 
mm.  wide.  The  pygal  bone  is  52  mm.  high  and  75  mm.  wide. 
The  tenth  peripheral  bone  is  85  mm.  along  the  free  border  and 
102  mm.  high.     There  are  11  pairs  of  peripherals. 

The  nuchal  scute  is  small,  about  25  mm.  long  and  15  mm. 
wide.  The  first  vertebral  scute  is  unsymmetrical.  On  the  left 
side  the  anterior  border  extends  100  mm.  from  the  midline;  on  the 
right  side  apparently  only  60  mm.  The  left  appears  to  be  the  nor- 
mal side.  The  table  herewith  gives  dimensions  of  the  vertebrals. 

It  will  be  observed  that,  with  the  exception  of  the  first  and  the  last,  the  vertebrals  are 
considerably  longer  than  wide.  The  costal  scutes  are  large.  The  second  has  a  longitudinal 
extent  of  160  mm.  and  a  height  of  240  mm.  They  extend  far  below  the  costo-peripheral 
sutures.  Of  the  marginal  scutes  there  are  12  pairs.  The  second  extends  from  the  free  border 
42  mm.  to  the  first  vertebral  scute.  The  third  has  a  height  of  60  mm.;  the  ninth  a  height  of 
60  mm.;   the  twelfth,  a  height  of  75  mm. 

On  the  lower  side  of  the  first  and  second  peripherals  the  portion  covered  by  the  horny 
scutes  is  about  50  mm.  wide.  Toward  the  nuchal  bone  and  the  axillary  notch  this  narrows 
greatly.  Behind  the  inguinal  notches  the  horn-covered  surface  on  the  lower  side  of  the  periph- 
erals is  about  45  mm.  wide  to  the  midline  behind. 

The  plastron  (plate  33;  text-fig.  289)  has  a  total  length  of  660  mm.  The  lobes  are  short, 
the  bridges  wide.  The  length  of  the  anterior  lobe,  to  a  line  joining  the  bottoms  of  the  axillary 
notches,  is  160  mm.  The  breadth,  taken  from  the  inner  border  of  one  axillary  notch  to  the 
other,  is  330  mm. 

Anteriorly  the  lobe  ends  in  a  beak  as  prominent  as  that  of  many  species  of  Testudo. 
From  the  anterior  end  of  one  gulo-humeral  sulcus  to  the  other,  the  width  is  95  mm.  The  beak 
extends  42  mm.  in  front  of  this.  On  the  lower  surface  the  beak  is  nearly  flat,  but  toward  the 
front  it  develops  a  broad  median  channel.  Laterally  the  borders  of  the  beak,  like  those  of 
the  whole  anterior  lobe,  are  subacute.  From  this  subacute  edge  the  bone  rises  abruptly  and 
nearly  perpendicularly,  finally  rounding  off  into  the  convex  upper  surface  of  the  beak.  The 
maximum  thickness  of  the  bone  is  50  mm.  On  the  upper  side  of  the  beak  the  ornamented 
surface  extends  back  about  55  mm.  From  the  sides  of  the  beak  this  sculptured  surface  narrows 
toward  the  axillary  notch.  At  the  junction  of  the  epiplastron  with  the  hyoplastron  the  bone 
is  35  mm.  thick.    The  median  portions  of  the  anterior  lobe  are  much  thinner. 

The  entoplastron  is  short  but  very  wide.  Its  fore-and-aft  extent  is  1 10  mm.,  the  breadth, 
145  mm.     The  form  is  shown  in  the  figures. 

The  bridges  are  about  370  mm.  wide.  The  hinder  lobe  has  a  length  of  145  mm.  and  a 
width  of  300  mm.  At  the  borders,  for  some  distance  behind  the  inguinal  notches,  the  bone 
turns  abruptly  and  perpendicularly  upward  to  the  summit  of  a  ridge  running  backward  from 
the  inguinal  notch.  From  the  summit  of  this  ridge  the  bone  slopes  rapidly  downward  to  the 
central  portion  of  the  lobe.    At  the  hypoxiphiplastral  suture  the  ridge  is  50  mm.  above  the 


DERMATEMYDID^.  23 1 

lower  surface  of  the  plastron;  at  the  femoro-anal  sulcus,  only  20  mm.  On  the  upper  surface 
of  each  xiphiplastron  is  a  scar  for  the  pubis.  This  scar  is  55  mm.  long  and  30  mm.  wide. 
The  inner  borders  of  the  two  are  100  mm.  apart.  The  hinder  end  of  the  lobe  is  truncated 
and  bent  upward  as  the  hinder  extremity  is  approacht. 

The  median  portion  of  the  plastron  is  very  concave,  a  condition  which  appears  to  indicate 
that  the  individual  was  a  male. 

On  some  parts  of  the  plastron  the  sulci  bounding  the  epidermal  scutes  are  very  distinct; 
in  others  they  are  obscure,  but  determinable.  They  consist  of  very  narrow,  thread-like  grooves, 
some  of  which  pursue  their  course  at  the  bottoms  of  broad  channels,  while  others  keep  on 
the  level  of  the  general  surface.  The  median  sulcus  runs  an  extremely  irregular  course,  being 
first  on  one  side  of  the  midline,  then  on  the  other.  The  intergulars  occupy  the  whole  lower 
surface  of  the  lip,  extending  backward  100  mm.  along  the  midline.  The  gulars  meet  at  the 
midline  a  distance  of  35  mm.     Their  posterior  borders  run  parallel  with  the  anterior. 

At  the  midline  the  humerals  join  for  a  distance  of  only  8  mm.;  but  from  this  they  expand 
rapidly  and  their  outer  ends  reach  about  60  mm.  behind  the  axillary  notch.  The  pectoral 
scutes  are,  fore  and  aft,  extremely  broad,  meeting  along  the  midline  a  distance  of  195  mm. 
Their  outer  ends  are  only  30  mm.  wide.  The  abdominal  scutes  extend  along  the  midline  160 
mm.,  while  their  outer  borders  are  240  mm.  long.  The  length  of  the  femorals  at  the  midline 
may  be  taken  as  90  mm.;   that  of  the  anals  as  the  same. 

The  scutes  covering  the  bridge  are  separated  from  the  plastral  scutes  just  described  by  a 
nearly  straight  sulcus  running  from  the  axillary  to  the  inguinal  notch.  Of  these  scutes  the 
most  anterior  and  the  posterior  alone  appear  to  represent  the  inframarginal  series.  The 
others  are  bridge  marginals.  Of  these,  one,  the  sixth  marginal,  has  become  greatly  expanded 
at  the  abdominal  end;  the  other  marginals  are  greatly  narrowed  at  their  lower  ends.  This 
absence  of  a  series  of  inframarginals  is  remarkable  in  this  family. 

The  sculpture  of  this  species  resembles  closely  that  of  its  predecessor,  B.  variolosa.  The 
carapace  and  the  plastron  are  both  rough  with  sharp  elevations,  which  are  usually  triangular 
pyramids.  These  are  mostly  arranged  in  rows,  of  which  three  or  four  are  spanned  by  a  line 
10  mm.  long. 

The  present  species  differs  from  B.  variolosa  in  various  points.  The  gulars  of  the  Judith 
River  species  are  crowded  far  from  the  median  line;  in  B.  sinuosa  they  are  in  contact  with 
each  other.  The  pectoral  scutes  of  B.  sinuosa  extend  backward  nearer  to  the  hyohypoplastral 
suture  than  they  do  in  B.  variolosa.  The  hinder  extremity  of  the  plastron  of  B.  sinuosa  is  trun- 
cated, bent  upward  somewhat,  and  has  its  borders  acute;  that  of  B.  variolosa  is  broadly 
rounded,  flat,  and  the  borders  are  thick  and  obtuse.  From  some  peripherals  present,  belonging 
to  the  type  of  B.  variolosa,  it  appears  that  the  sculptured,  horn-covered  surfaces  on  the  under 
side  of  the  peripherals  are  considerably  broader  than  they  are  in  B.  sinuosa.  On  the  eighth 
peripheral  this  surface  is  70  mm.  wide;  in  B.  sinuosa  it  is  only  50  mm.  wide.  The  plastron 
of  the  type  of  B.  variolosa  is  only  about  10  mm.  longer  than  that  of  B.  sinuosa  Riggs. 

A  fragment  of  the  epiplastral  Hp  of  what  is  regarded  as  this  species  was  found  by  Mr. 
Barnum  Brown  of  the  American  Museum,  on  Hell  Creek,  Dawson  County,  Montana. 

Basilemys  imbricaria  (Cope). 
Plate  32,  figs.  5,  6,  7;   teit-figs.  290,  291. 

Compsemys  imhricarius,  CoPE,  Proc.  Acad.  Nat.  Sci.  Phila.  1876,  p.  257;    Bull.  U.  S.  Geol.  Surv.,  iii, 

'877,  p.  573. 
Basilemys  imhricarius.  Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  445.— Hatcher,  Bull.  U.  S. 

Geol.  Surv.  No.  257,  1905,  p.  77. 
Adocus  {Basilemys)  imhricarius,  OsBORN,  Cont.  Canad.  Palaeont.,  Ill  (4^0),  1902,  p.  16. 

This  species  was  founded  by  Professor  Cope  on  very  unsatisfactory  materials.  The  type, 
to  which  only  three  fragments  (No.  6102  of  the  American  Museum  of  Natural  History)  can  be 
referred  with  any  certainty,  was  found  in  the  Cope  collection  mingled  with  fragments  of  two 
or  three  other  species.  The  identified  bones  are  here  figured  of  the  natural  size  (plate  32, 
figs-  5,  6,  7).  All  are  probably  portions  of  costal  plates.  The  larger  piece  is  traverst  by  a 
narrow  and  sharply  imprest  sulcus,  and  appears  to  be  the  fragment  mentioned  by  Cope  as 


232 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


having  the  direction  of  the  ridges  of  sculpture  running  at  right  angles  with  the  sulcus.  The 
inner  surface  of  the  bone  is  removed,  so  that  the  thickness  of  the  fragment  can  not  be  deter- 
mined.   It  was  more  than  6  mm. 

The  piece  of  medium  size  has  a  sutural  edge  along  one  side.  The  thickness  is  6  mm. 
where  thickest,  5  mm.  where  thinnest;  and  it  may  be  the  fragment  whose  measurement  Cope 
gave.    The  smallest  piece  of  bone  is  only  3  mm.  thick. 

This  species  is  distinguisht  especially  by  its  sculpture.     It  is  thus  described  by  Cope: 

It  consists,  in  the  Compsemys  imbricarius,  of  excavations  bounded  on  the  sides  by  a  short  ridge 
each,  which  [excavations]  alternate  with  each  other.  Thus  each  bounding  ridge  terminates  abruptly 
at  the  fundus  of  one  of  the  fossae,  while  the  other  end  of  the  fossa  rises  and  contracts  into  another 
ridge.  The  result  is  precisely  that  seen  in  the  interior  sculpture  of  Saracenic  domes  and  niches, 
and  is  one  quite  unique  among  tortoises.  The  direction  of  the  ridges  is  at  right  angles  to  the  costal 
dermal  sutures. 

Cope  states  that  three  of  the  fossae  measure  in  length  6.5  mm.  and  crosswise,  5  mm.  In  the 
case  of  the  largest  of  the  three  fragments  of  the  type  three  fossae  taken  together  measure  7  mm. 
and  crosswise,  6  mm. 

While  this  style  of  ornamentation  appears  to  be  very  peculiar,  something  scarcely  dis- 
tinguishable in  pattern  may  be  seen  here  and  there  on  the  carapace  of  B.  variolosa,  and  for 
that  reason  the  present  species  has  been  referred  to  Basilemys.  In  fact  Cope  has  labeled  as 
Compsemys  tmbricaria  some  fragments  the  sculpture  of  which  appears  quite  identical  with  that 
of  B.  variolosa.  With  these  latter  fragments,  however,  there  is  what  seems  to  be  the  thickened 
rim  of  the  front  of  the  carapace  (fig.  290,  No.  6100  A.  M.  N.  H.),  and  this  is  plainly  different 
from  that  of  B.  variolosa.  Evidently  there  is  another  species  occurring  with  B.  variolosa, 
related  to  it,  but  differing  in  important  characters.  For  this  species  we  may  for  the  present 
retain  the  name  Basilemys  imhricaria. 

The  remains  of  this  form  were  collected  in  1876,  in  the  Judith  River  beds  of  Montana,  by 
Mr.  Charles  H.  Sternberg. 

Fig.  290  represents  a  section  across  the  supposed  anterior  peripheral,  No.  6100  A.  M.  N.  H. 

The  part  of  this  peripheral  which  joins  the  costal 
,^^  is  missing.    On  the  under  side  it  appears  to  extend 

■''llJmlll  11  lfl)V  backward  to   the   line  reacht  by  the  soft  skin,  a 

jflllM  lllll  Ijk  distance  of  27  mm.  from   the  free  border.      The 

,.g  extreme  thickness  of  the  fragment  is  16  mm.    The 

upper  surface  is  slightly  convex;  the  lower  surface 

Figs.  290  AND  291. -5<2.</.my^/mJnW;fl.     strongly  SO.    The  ornamentation   is   coarse,  there 

Sections.     X§.     No.  6101  A.  M.  N.  H.        being  3  fossae  in  9  mm.  This  peripheral  differs  from 

290.  Section  across  peripheral.  one  in  the  Same  region  of  B.  variolosa  in  having 

201.  Section  across  border  of  xiphiplastron.  ,  ,  ,  r  i  i-irii 

'  the  sculptured  surface  on  the  under  side  of  the  bone 

much  narrower  from  the  free  edge  to  the  skin  line  in  proportion  to  the  thickness  of  the  bone. 

It  is  to  be  noted  that  these  coarsely  sculptured  fragments  possibly  do  not  belong  to  B. 
imhricaria. 

In  the  Cope  collection  there  is  another  fragment  (No.  610 1)  which  possesses  a  sculpture 
like  that  of  the  specimens  just  described,  and  this  is  evidently  a  portion  of  the  left  xiphiplastron 
(fig.  291).  There  are  3  fossae  in  8  mm.  It  differs  from  that  of  5.  variolosa  in  having  a  sharp 
border  separating  the  lower  surface  from  the  surface  which  looks  outward  and  upward.  In 
B.  variolosa  the  lower  surface  of  the  hinder  lobe  rounds  gradually  into  the  upper  surface. 

Professor  Cope  has  labeled  as  Compsemys  imhricaria  other  specimens  from  the  Judith 
River  beds  which  have  a  sculpture  similar  in  pattern  but  much  more  delicate.  In  these 
(No.  6103  A.  M.  N.  H.),  some  of  them  fragments  of  costals,  there  are  4  fossae  in  a  line  5  mm. 
long.  The  scutal  sulci  are  thread-like.  Other  fragments,  peripherals  from  the  bridge  perhaps, 
have  similar  ornamentation  but  the  sulci  are  very  broad.  It  seems  very  probable  that  the 
fragments  here  described  belong  to  more  than  one  species,  but  the  discovery  of  additional  and 
much  better  materials  will  be  required  in  order  to  determine  the  structure  and  generic  position 
of  Cope's  Compsemys  imhricaria. 


DERMATEMYDID^.  233 

Genus  COMPSEMYS  Leidy. 

Little-known  turtles  belonging  probably  to  the  Dermatemydidae.  Free  surfaces  of  the 
bones  of  carapace  and  plastron  ornamented  with  small,  close-set,  enameled  tubercles  which 
produce  the  appearance  of  shagreen.  Neurals  hexagonal,  with  the  broader  end  forward. 
Costals  without  distal  prolongations  into  the  peripherals.  Sulci  thread-like.  The  plastron 
suturally  articulated  with  the  contiguous  peripherals  and  sending  up  axillary  and  inguinal 
buttresses  to  the  costals.  No  evidences  of  mesoplastra.  Inframarginal  scutes  probably  on 
the  bridges.    Vertebral  scutes  not  greatly  expanded. 

Type:    Compsemys  victus  Leidy. 

The  genus  Compsemys  was  establisht  in  1856  by  Professor  Leidy,  to  receive  the  scanty 
remains  which  he  named  Compsemys  victus.  Later  discoveries  have  added  little  to  our 
knowledge  regarding  the  genus;  altho  it  is  evident  that  it  is  represented  over  a  wide  area  of 
territory  and  thru  a  considerable  range  of  deposits,  having  been  reported  from  levels  rang- 
ing from  the  Judith  River  beds  to  the  Denver.  The  only  characterization  that  Leidy  gave  to 
his  genus  is  exprest  in  the  following  words: 

The  peculiarity  of  the  specimens  which  has  led  to  the  proposal  of  the  genus  consists  in  their  exterior 
surface  being  closely  studded  with  uniform  granular  tubercles,  which  give  to  them  a  shagreened  appear- 
ance, quite  different  from  anything  I  have  had  the  opportunity  of  seeing  in  other  turtles. 

At  a  later  time  Professor  Cope  assigned  to  Compsemys  Leidy's  Emys  obscurus  and  after- 
wards returned  it  to  Emys.  At  the  same  time  he  referred  to  Compsemys  his  own  Adocus 
lineolatus  without  explanation.  These  two  species  undoubtedly  belong  elsewhere.  The 
same  verdict  must  be  pronounct  regarding  the  three  species  described  by  Cope  in  1875  and 
1876,  from  the  Judith  River  beds,  and  called  by  him  Compsemys  ogmius,  C.  tmhricurtus, 
and  C.  variolosus.  In  1877  Cope  described  his  Compsemys  plicatula  from  the  Jurassic  of 
Colorado,  and  there  can  be  little  doubt  that  his  generic  reference  of  the  specimen  was  based  on 
the  similarity  of  the  sculpture  to  Leidy's  species.  Especially  since  Dr.  Baur's  description  of 
Cope's  C.  plicatula  it  has  been  regarded  as  representing  the  characters  of  Compsemys.  How- 
ever, there  can  be  no  doubt  that  plicatula  belongs  to  a  wholly  different  genus  from  victa,  and 
to  another  superfamily.  Most  of  the  references  in  scientific  literature  to  the  genus  Compsemys 
(for  which  see  the  writer's  Bibliography  and  Catalogue  of  Fossil  Vertebrata  N.  A.,  1902, 
p.  437)  are  to  the  genus  as  typified  by  C.  plicatula  and  are  therefore  to  be  transferred  to 
Glyptops.  When  Baur  (Proc.  Acad.  Nat.  Sci.  Phila.  1891,  p.  412)  states  that  the  Laramie 
forms  of  Compsemys  show  all  the  characters  of  the  Jurassic  form  he  seems  to  have  had  in  mind 
Cope's  Compsemys  variolosa,  but  this  certainly  has  no  mesoplastron. 

So  far  as  at  present  known  the  only  species  to  be  assigned  with  any  certainty  to  this  genus 
is  the  type,  C.  victa.  It  is  probable  that  when  the  form  that  has  been  reported  to  occur  in 
the  Judith  River  beds  is  better  known  it  will  prove  to  be  a  second  species. 

Compsemys  victa  Leidy. 

Plate  34,  figs.  J,  3;   teit-figs.  292-295. 

Compsemys  victus,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1856,  p.  312;  Trans.  Amer.  Philos.  Soc,  xi, 
i860,  p.  152,  plate  vi,  figs.  5-7. — CoPE,  Trans.  Amer.  Philos.  Soc,  xiv,  1869,  p.  124;  Seventh  Ann. 
Report  U.  S.  Geol.  Surv.  Terrs.,  1873  (1874),  p.  454;  Bull.  U.  S.  Geol.  Surv.,  i.  No.  2,  1874,  p.  30; 
Vert.  Cret.  Form.  West,  1875,  pp.  91,  261,  plate  vi,  figs.  15,  16;  .'Brit.  N.  A.  Bound.  Comm.  Report, 
1875,  pp.  333,  336;  ?BulI.  U.  S.  Geol.  Surv.,  iii,  1877,  p.  573. —  ?Cross,  Monogr.  U.  S.  Geol.  Surv., 
XXVII,  1896,  p.  227.— .'Marsh,  Monogr.  U.  S.  Geol.  Surv.,  xxvii,  1897,  p.  527.— Hay,  Bibliog.  and 
Cat.  Foss.  Vert.  N.  A.,  1902,  p.  437. 

Professor  Leidy's  type  of  the  present  species  consisted  of  a  neural;  a  considerable  portion 
of  a  costal,  regarded  as  a  fifth;  and  a  fragment  of  the  eighth  costal.  These  are  now  in  the 
U.  S.  National  Museum  and  bear  the  number  960.  They  were  secured  in  deposits  of  probably 
Laramie  age,  at  Long  Lake,  North  Dakota.  The  species  was  afterward  reported  by  Cope 
from  supposed  Laramie  deposits  in  Colorado,  now  regarded  as  Arapahoe  or  Denver  (Cross, 
op.  cit.,  pp.  227,  244),  and  with  doubt  from  Judith  River  beds  (Cope's  Fort  Union)  and  from 


234 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


beds  of  the  same  period  in  the  region  about  Milk  River,  British  America.  As  the  Judith 
River  beds  are  now  known  to  be  much  lower  in  the  geological  scale  than  the  Laramie  it  is 
probable  that  a  distinct  species  is  there  included.  The  Arapahoe  and  Denver  beds  being  prob- 
ably above  the  Laramie,  it  is  not  improbable  that  the  remains  reported  from  that  horizon  by 
Cope  and  Marsh  belong  to  a  third  species  of  the  genus. 

Leidy's  type  indicated  a  turtle  whose  carapace  had  a  length  of  about  365  mm.  The  neural, 
regarded  as  the  fourth,  was  26  mm.  long  and  27  mm.  wide.  The  costal  plate  believed  to  be 
the  fifth,  was  28  mm.  wide  at  the  middle  of  the  length.  It  is  rather  strongly  archt,  showing  that 
the  shell  was  not  deprest.  This  costal  had  a  thickness  of  7  mm.  where  it  joined  the  neurals. 
It  is  crost  at  the  proximal  end  by  the  costo-vertebral  sulcus,  from  which  proceeds  the  sulcus 
that  separated  the  third  and  fourth  vertebral  scutes.  The  position  of  the  longitudinal  sulcus 
indicates  that  the  vertebrals  had  a  width  of  about  65  mm.  Leidy's  estimate  that  they  were 
2  inches  wide  is  too  small. 

The  specimens  figured  by  Cope  in  his  Vertebrata  of  the  Cretaceous  Formations  of  the  West, 
plate  vi,figs.  15,  16,  were  collected  in  1873,  in  northeastern  Colorado.  No  statement  is  made  as 
to  the  exact  locality,  but  they  probably  came  from  the  Denver  beds  in  the  region  about  Bijou 
Creek.  We  can  not  be  really  certain  that  they  belong  to  Leidy's  species.  Cope's  fig.  16 
represents  a  posterior  peripheral,  apparently  the  ninth  of  the  left  side,  with  the  sulcus  between 
the  third  and  fourth  costals  running  down  its  anterior  half.  The  bone  is  39  mm.  high,  32  mm. 
wide  at  the  free  border,  and  9  mm.  thick  at  the  costal  border.  There  is  no  pit  for  the  rib-end. 
The  bone  thins  to  an  acute  free  border.  The  upper  surface  is  only  slightly  concave.  The 
sculpture  resembles  that  of  the 
type  of  the  species.  A  remarkable 
feature  of  this  bone  is  the  low 
position  of  the  costo-marginal 
sulcus.  This  runs  much  nearer 
the  free  than  to  the  costal  border. 

Figs.   292-295. — Compsemys  victa. 
Fragments  of  shell,      xj. 

292.  Portion  of  right  costal.     No.  6096 

A.  M.  N.  H. 

293.  First  right  peripheral.    No.  1085 

A.  M.  N.  H. 

294.  Fragment  of  bridge  peripheral.  No. 

998  A.  M.  N.  H. 

295.  Portion  of  right  hyoplastron.    No, 

1015  A.  M.  N.  H. 

In  Glyptops  plicatulus,  as  is  usual  in  turtles,  it  runs  nearer  the  costal  border.  In  the  periph- 
eral here  described  the  scute-covered  surface  on  the  inferior  side  of  the  bone  extends  to  within 
15  mm.  of  the  costal  border.  The  granulation  is  finer  than  on  the  upper  side  of  the  bone. 
The  other  fragment  figured  by  Cope  furnishes  little  additional  information. 

A  right  eighth  costal,  No.  6096  of  the  American  Museum  of  Natural  History,  collected  by 
Mr.  J.  C.  Isaac,  in  1877,  in  the  Laramie  beds,  on  Lance  Creek,  Wyoming,  was  at  least  40  mm. 
wide  and  from  5  mm.  to  8  mm.  thick  (plate  34,  fig.  3;  text-fig.  292).  The  proximal  portion  and 
a  part  of  the  hinder  border  are  broken  away.  On  the  lower  surface  there  is  the  base  of  a 
strongly  developt  rib-head;  but  there  is  no  ridge  corresponding  to  the  rib,  nor  any  projecting 
distal  end  of  the  rib,  such  as  we  find  in  Glyptops.  Near  the  hinder  border  of  the  bone  is  a  sulcus, 
that  separating  the  fourth  costal  scute  from  the  fifth  vertebral.  On  the  peripheral  border  are 
two  loops  of  a  sulcus,  one  narrow,  the  other  wider.  These  appear  to  have  proceeded  from  the 
peripheral;  but  as  the  peripheral  figured  by  Cope  shows  the  costo-marginal  sulci  to  have  run 
low  down  on  the  peripherals,  the  presence  of  these  loops  on  the  costal  is  at  present  inexplicable. 
Similar  irregularly  meandering  sulci  are  seen  on  other  bones.  The  oblique  hinder  sutural  edge 
of  the  costal  probably  articulated  with  the  eleventh  peripheral  and  with  the  suprapygal.  The 
fourth  costal  scute  may  have  occupied  a  portion  of  the  suprapygal,  as  it  does  in  Kinosternon. 
In  the  U.  S.  National  Museum  there  is  a  neural,  the  second  or  fourth,  which  was  collected  by 
Mr.  J.  B.  Hatcher,  on  Lance  Creek,  Wyoming. 


dermatemydidje.  235 

In  1902,  Mr.  Barnum  Brown,  of  the  American  Museum,  collected  a  few  fragments  of  this 
species  in  Laramie  beds  on  Hell  Creek,  Dawson  County,  Wyoming.  One  is  the  first  right 
peripheral  (fig.  293).  The  individual  (No.  1085  A.  M.  N.  H.)  was  a  relatively  small  one.  The 
fore-and-aft  extent  of  the  bone  is  23  mm.,  and  the  thickness  of  the  hinder  border,  5  mm.  The 
free  edge  is  acute.  The  first  marginal  scute  is  only  5  mm.  antero-posteriorly  where  it  joins  the 
second.  The  latter  widens  to  9  mm.  at  the  suture  between  the  first  and  the  second  peripherals. 
On  the  under  side  of  the  bone  the  sculptured,  horn-covered  surface  is  about  7  mm.  wide  at 
the  suture  with  the  second  peripheral,  but  toward  the  nuchal  it  narrows  to  3.5  mm. 

Of  the  bridge  peripherals  there  is  a  portion  of  one  in  the  American  Museum,  No.  998, 
collected  by  Mr.  Brown  in  1900,  in  Laramie  deposits  of  Wyoming,  about  40  miles  west  of 
Edgemont,  South  Dakota.  This  fragment  (fig.  294)  shows  that  there  was  no  sharp  carina 
above  the  bridge,  but  an  obtuse,  rounded  ridge.  Fig.  2,  plate  34,  represents  what  is  probably 
the  distal  end  of  the  fourth  costal.  Besides  the  descending  sulcus  there  are  again  seen  some 
irregular  loops  coming  up  from  the  contiguous  peripherals. 

Of  the  plastron  there  are  only  fragments  known.  Fig.  295  represents  what  appears  to 
be  the  left  outer  extremity  of  the  hyoplastron  of  a  young  individual  from  Hell  Creek,  No. 
1015  A.  M.  N.  H.  The  zigzag  sutural  border  is  for  articulation  with  the  peripherals,  appar- 
ently the  third,  fourth,  and  fifth.  This  border  is  only  2  mm.  thick.  The  longitudinal  sulcus 
is  that  which  passes  from  the  axillary  to  the  inguinal  notch.  The  short  branch  on  the  right 
appears  to  be  the  pectoro-abdominal.  The  three  scute  areas  on  the  left  may  be  inframarginals 
or  they  may  be  marginals.  If  inframarginals,  they  extend  wholly  beyond  the  plastral  bones. 
On  the  inner  side  of  this  bone  is  seen  a  portion  of  the  strongly  developt  buttress  which  rose  to 
the  border  of  a  costal,  probably  the  first.  It  is  possible  that  the  bone  here  described  really 
belongs  to  the  inguinal  region.  In  either  case  there  is  indicated  the  absence  of  a  mesoplastron. 
On  the  mesoplastron  of  Glyptops  and  of  Baena  there  is  one  inframarginal.  There  are  three 
on  the  bone  above  described.     There  would  thus  be  seven  probably  on  each  bridge. 

It  will  be  seen  from  the  descriptions  given  here  of  this  species  that  it  is  very  imperfectly 
known.  Additional  materials  ought  to  be  sought  by  collectors.  Evidently  it  was  a  species 
that  attained  a  considerable  size  and  which,  when  grown,  possest  a  thick  shell.  Its  sculptured 
upper  and  lower  surfaces  must  have  rendered  it  a  beautiful  animal. 

Compsemys?  obscura  (Leidy). 
Plate  34,  fig.  4. 

Emys  obscurus,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1856,  p.  312;  Trans.  Amer.  Philos.  Soc,  xi,  i860, 
p.  153,  plate  xi,  fig.  4.— Cope,  Bull.  U.  S.  Geol.  and  Geog.  Surv.  Terrs.,  lii,  1877,  p.  573. 

Compsemys  obscurus,  CoPE,  Trans.  Amer.  Philos.  Soc,  1869,  xiv,  p.  124;  Bull.  U.  S.  Geol.  and  Geog. 
Surv.  Terrs,  I,  No.  2,  1874,  p.  30;  Vert.  Cret.  Form.  West,  1875,  p.  261. — Hay,  Bibliog.  and  Cat. 
Foss.  Vert.  N.  A.,  1902,  p.  437. 

This  species  is  retained  here  under  the  genus  Compsemys  because  it  has  already  been 
placed  there  by  Cope  and  Leidy  and  because  we  do  not  know  where  else  to  place  it.  There  is 
little  evidence  that  it  is  closely  related  to  Compsemys  victa  and  there  is  no  probability  that 
it  is  an  Emys,  in  the  modern  acceptation  of  that  term. 

Leidy's  type  of  his  Emys  obscurus  was  found  by  Dr.  F.  V.  Hayden  at  Long  Lake,  in  the 
present  state  of  North  Dakota,  in  deposits  that  are  now  regarded  as  belonging  to  the  Laramie. 
The  writer  does  not  know  where  the  type  is  to  be  found.  The  part  figured  and  described  by 
Leidy  is  a  portion  of  a  costal  plate,  extending  from  the  costo-vertebral  sulcus  to  the  costo- 
peripheral  suture.  This  costal  is  33  mm.  wide,  60  mm.  long  from  the  sulcus  to  the  distal  end, 
and  little  more  than  3  mm.  thick.  The  surface  is  described  by  Leidy  as  being  smooth.  His 
figure  shows  that  the  sutural  borders  were  markt  by  fine  striations  at  right  angles  to  the 
sutures. 

In  the  American  Museum  of  Natural  History  there  are  the  proximal  ends  of  2  costals 
which  were  found  by  Mr.  Barnum  Brown,  in  1902,  in  Laramie  deposits,  on  Hell  Creek, 
Dawson  County,  Montana.  These  are  identified  as  belonging  to  the  species  here  described. 
One  of  these  fragments  (plate  34,  fig.  4)  appears  to  belong  to  the  second  left  costal.    It  is  31 


236  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

mm.  wide,  6  mm.  thick  at  the  articulation  with  the  neural,  and  3  mm.  at  the  sutural  border, 
just  beyond  the  costo-vertebral  sulcus.  The  proximal  end  is  occupied  by  one  of  the  vertebral 
scutes.  Near  the  posterior  border  of  the  bone  the  scute  overlapt  the  bone  about  20  mm. 
The  sulci  are  rather  narrow.  A  broad  band  of  fine  striations  borders  the  sutures,  the  striations 
being  at  right  angles  with  the  latter.  The  remainder  of  the  surface  is  markt  by  delicate  ridges 
and  pits  appreciable  only  under  a  lens. 

The  other  fragment  mentioned  belonged  to  the  third  or  the  fifth  costal  of  one  side  or  the 
other;  and  it  bears  a  portion  of  the  sulcus  between  two  vertebral  scutes.  This  sulcus  extends 
along  the  bone  a  distance  of  27  mm.  without  joining  the  costo-vertebral  sulcus;  so  that  we 
may  conclude  that  the  hinder  vertebral  scutes  were  somewhat  wider  than  the  anterior. 

This  species  is  included  by  Cope  in  his  list  of  Judith  River  fossils,  but  the  writer  knows 
of  no  specimens  that  confirm  the  statement. 

Genus  ADOCUS  Cope. 

Carapace  firmly  articulated  to  plastron  by  sutures  between  the  bridge  peripherals  and  the 
hyoplastrals  and  hypoplastrals,  and  by  axillary  and  inguinal  buttresses.  Heads  of  ribs,  except 
that  of  first  costal  bone, vestigial.  Free  borders  of  the  peripherals  acute.  Scutes  of  the  carapace 
normal;  most  of  the  marginals  rising  and  overlapping  the  lower  ends  of  the  costal  bones. 
Lobes  of  the  plastron  somewhat  reduced;  the  hinder  not  notcht.  Plastral  scutes  7  pairs;  the 
intergulars  excluding  the  gulars  from  contact  on  the  midline.     Inframarginals  present. 

Type:    Emys  beatus  Leidy. 

The  genus  Adocus,  as  here  defined,  is  at  present  known  only  from  Upper  Cretaceous 
species;  and,  except  A.  lineolatus,  doubtfully  referred  to  the  genus,  all  are  from  the  Upper 
Cretaceous  greensand  of  the  eastern  United  States.  Adocus  may  be  regarded  as  the  least 
modified  of  the  Dermatemydidae.  Its  advanct  characters  appear  to  be  found  in  the  slightly 
reduced  number  of  neurals,  one  or  two  of  the  most  posterior  probably  being  usually  missing; 
in  the  developt  buttresses;  in  the  aborted  rib-heads;  and  in  the  reduced  gular  scutes.  Prim- 
itive characters  are  found  in  the  possession  of  seven  pairs  of  plastral  scutes  and  the  unin- 
terrupted series  of  inframarginals. 

The  following  key  may  be  of  some  value  in  separating  the  species: 

Key  to  Species  of  Adocus. 

A.  Species  of  the  Rocky  mountain  region;  not  well  known lineolatus 

AA.  Species  of  eastern  United  States  region. 

a.  Hinder  lobe  of  plastron  narrowed  behind. 

h.  Entoplastron  wide;  nearly  equal  to  length  of  the  suture  between  the  hyoplastrals         beatus 

bb.  Entoplastron  narrow;   width  nearly  twice  in  the  hyoplastral  suture pravus 

aa.  Hinder  lobe  broad  behind;    rounded  or  truncated. 

c.  Gulo-humeral  sulcus  close  to  or  crossing  the  entoplastron. 

d.  Hinder  lobe  truncated  behind;   the  length  between  three-fifths  and 

four-fifths  the  width  at  the  base punctatus 

dd.  Hinder  lobe  broadly  rounded;  its  length  three-fifths  the  width  at  the 

base;  gulo-humeral  sulcus  just  in  contact  with  the  entoplastron.  .   synthettcus 
ddd.  Hinder  lobe  broadly  rounded;  its  length  four-fifths  the  width  at  base; 

gulo-humeral  sulcus  well  forward  on  entoplastron lacer 

cc.  Gulo-humeral  sulcus  falling  considerably  behind  the  entoplastron agtlts 

Adocus  punctatus  Marsh. 
Plate  34,  figs.  6,  7;   plate  35,  figs,  i,  2;   text-figs.  296-298. 

Adocus  punctatus.  Marsh,  Amer.  Jour.   Sci.  (3),  XL,  1890,  p.  178,  plate  vii,  fig.  3. — ^Wieland,  Amer. 

Jour.  Sci.  (4),  XVII,  1904,  p.  112,  plates  i-iv,  text-figs,  i,  2. 
Adocus  beatus,  Baur,  Proc.  Acad.  Nat.  Sci.,  1891,  p.  428. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A., 

1902,  p.  444. 

At  the  present  time  this  species  is  represented  by  better   materials  than  any  other  of 
the  genus,  and  for  that  reason  it  is  here  described  first  of  all  the  species  of  Adocus.    The 


DERMATEMYDID^. 


237 


in.s.l 


type  belongs  to  the  Marsh  collection  in  Yale  University  Museum  and  presents  the  nearly 
complete  shell.  It  was  obtained  in  the  upper  bed  of  Cretaceous  marl  at  Hornerstown,  Mon- 
mouth County,  New  Jersey,  in  1872.    It  has  been  restored  and  fully  described  by  Dr.  G.  R. 

Wieland,  as  cited  in  the  synonymy.  Dr. 
Wieland's  figures  are  employed  in  the  pres- 
ent work  to  illustrate  the  structure. 

The  total  length  of  the  carapace  (plate 
35>  fig-  i;  text-fig.  296)  in  a  straight  line  is 
533  •Ti'"-  The  greatest  width  is  390  mm. 
The  form  is  that  of  an  elongated  oval, 
broadest  behind  the  middle,  rounded  in 
front,  more  broadly  rounded  behind.  Dr. 
Wieland  has  called  attention  to  a  double 
curvature  along  the  sides.  Possibly  this 
is  due  to  slight  distortion.  From  side  to 
side  anteriorly  the  carapace  is  quite  evenly 
convex;  posteriorly  in  the  restoration  it  is 
somewhat  flattened.  The  hinder  periph- 
erals are  flared  somewhat  upward,  but  the 
front  ones  are  not.  The  peripherals  of  the 
free  borders  are  thin  and  reduced  to  an 
acute  edge.  In  front  of  the  axillary  notch 
the  edges  of  the  peripherals  are  somewhat 
reverted,  leaving  a  groove  within  the  edges. 
The  nuchal  bone  is  70  mm.  long  on  the 
midline;  65  mm.  wide  on  the  free  edge;  95 
mm.  where  widest.  There  were  7  neurals, 
of  which  all  are  present  except  the  sixth. 
Its  form  and  dimensions  are  determinable 
from  the  surrounding  bones.  The  seventh 
was  not  developt;  the  eighth  is  small.  The 
table  below  presents  the  dimensions  of  the 
neurals. 

Most  of  the  neurals  are  hexagonal, 
with  the  broader  end  forward.  The  first 
has  the  broader  end  behind;  the  second  is  octagonal.  The  absence  of  the  seventh  neural 
permitted  the  seventh  pair  of  costals  to  meet  in  the  midline.  Those  of  the  eighth  pair  also 
meet  in  the  midline  in  front  of  the  eighth  neural.  The  single  suprapygal  is  octagonal,  70 
mm.  long  and  no  mm.  wide. 

The  peripherals  are  in  general  large.  Their  height,  at  right  angles  with  the  free  border, 
increases  from  the  third  to  the  ninth;  the  tenth  has  nearly  the  height  of  the  ninth;  the  eleventh 
is  considerably  smaller.  The  first  peripheral  extends  along  the  free  border  63  mm.;  and 
from  this  to  the  first  costal,  65  mm.  The  second  is  slightly  smaller  in  both  dimensions.  The 
third  occupies  50  mm.  of  the  free  border  and  is  65  mm.  high.  The  ninth  is  75  mm.  along  the 
free  edge  and  103  mm.  high.     The  eleventh  occupies  62  mm.  of  the  free  border  and  rises 

toward  the  suprapygal  70  mm.    The  pygal  measures  65  mm. 
along  the  free  edge  and  is  60  mm.  high. 

The  sulci  are  usually  rather  narrow  and  shallow.  Those 
on  the  front  are  somewhat  deeper  and  broader.  The  table  on 
page  238  gives  the  dimensions  of  the  vertebral  scutes. 

The  costal  and  the  marginal  scutes  are  of  unusual  confor- 
mation. The  anterior  marginals  are  mostly  small;  the  lateral  and 
posterior  remarkably  large.  As  a  result,  most  of  the  costals  are 
considerably  reduced  in  area.  The  nuchal  scute  is  16  mm.  long 
and  only  6  mm.  wide.  From  this  the  marginals  continue  to  rise 
slowly  above  the  free  border  to  the  hinder  end  of  fourth,  which 


F1G.296. — Adocus punctatus.  Carapaceoftype.  X0.18. 

c.p.ifC.  p.ijC.p.  8,  costal  plates;  m.i.  i,  m.j.  12,  marginal  scutes; 
nu.p,  nuchal  plate;  per^  2,  ptr,  11,  peripheral  bones;  pv, 
pygal ;   tpy^  suprapygal ;   w.  i,  n.  6,  neural  bones. 


Neural. 

Length. 

Width. 

I 

70 

38 

2 

39 

17 

3 

S» 

40 

♦ 

47 

37 

S 

4« 

38 

6 

44 

35 

7 

8 

40 

»4 

238 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


has  a  height  of  45  mm.  All  of  these  lie  wholly  on  the  peripherals.  The  fifth  marginal 
suddenly  rises  to  a  height  of  100  mm.  and  overlaps  the  lower  ends  of  the  second  and  third 
costal  bones.     The  ninth  marginal  has  a  height  of  145  mm.     The  next  two  are  only  slightly 

lower.  The  supracaudal  scutes  meet  along  the  midline  a  dis- 
tance of  97  mm.  The  costal  scutes  diminish  in  size  from  the  first 
to  the  last.  The  latter  has  a  fore-and-aft  length  of  80  mm.  and  a 
width  of  55  mm. 

The  plastron  (plate  35,  fig.  2;  text-fig.  297),  as  in  other  spe- 
cies of  the  genus,  is  relatively  small.  Both  the  anterior  and  the 
posterior  lobes  are  truncated.  The  total  length  is  355  mm.  The 
anterior  lobe  has  a  length  of  80  mm.  and  a  width  of  175  mm.  at 
the  base.  The  truncated  anterior  end  is  85  mm.  wide.  The 
entoplastron  is  50  mm.  long  and  70  mm.  wide.  The  bridges  are  140  mm.  wide.  The  posterior 
lobe  is  130  mm.  long  and  175  mm.  wide  at  the  base.  The  posterior  truncated  end  is  about 
80  mm.  wide.  The  free  borders  of  both  lobes  are  acute.  The  plastron  articulates  with  the 
peripherals  by  means  of  sutures;    and  axillary  and  inguinal  buttresses  rise  nearly   to  the 


Vertebral. 

Length. 

Width. 

100 

140 

95 

90 

100 

85 

98 

80 

80 

80 

'infill- 


c.p.j 


mnJJ 


Fig.  297. — Adocus  punctatus.     Lower  side  of  shell.     X0.16. 

ail,  abdominal  scute ;  an,  anal  scute  ;  c. />.  i,  c./i.  2,  etc.,  costal  plates;  «nl,  entoplastron  ;  «/)i,  epiplastron  ;  fern, 
femoral  scute;  |f,  gular  scute;  Aum,  humeral  scute  ;  A^o,  hyoplastron;  /()'/>o,  hypoplastron;  /j^,  intergular 
scute  ;  injnjj  inframarginal  scutes  ;  nu,  nuchal  bone;  pec,  pectoral  scute;  per.  3,  per.  8,  peripheral  bones; 
py,  pygal;    spy,  suprapygal;    xiph,  liphiplastron. 

lower  ends  of  the  costal  bones.  Plate  34,  fig.  5,  from  a  drawing  made  for  Dr.  Baur,  repre- 
sents the  upper  side  of  the  xiphiplastral  bones.  There  are  very  distinct  curved  depressions 
for  the  pubic  bones,  but  there  was  no  sutural  articulation  of  the  latter  bones  with  the  plastron. 
The  sutures  between  the  various  bones  of  the  plastron  are  somewhat  irregular,  as  is  shown 
in  the  figures.  The  sulci  are  still  more  irregular,  especially  the  longitudinal  median.  All  the 
sulci  are  narrow  and  shallow.  The  intergulars  have  pushed  the  gulars  away  from  contact  at 
the  midline,  and  neither  gulars  nor  intergulars  overlap  the  entoplastron.  The  humerals  occupy 
42  mm.  of  the  midline.  The  pectorals  measure  40  mm.  along  the  midline  and  they  overlap  the 
hinder  end  of  the  entoplastron.  The  abdominals,  the  femorals,  and  the  anals  respectively 
occupy  88  mm.,  82  mm.,  and  72  mm.  of  the  midline.  There  are  3  inframarginals  on  each  of 
the  bridges. 


DERMATEMYDID^.  239 

Both  the  carapace  and  the  plastron  of  this  species  are  ornamented  with  rows  of  shallow 
pits.     On  the  carapace  these  pits  are  arranged  mostly  in  rows  that  run  obliquely  across  the 

costal,  neural,  and  peripheral  bones.  On  the  median  parts  of 
the  plastron  the  pits  are  less  distinct,  but  still  evidently  present. 
The  relationships  of  this  species  to  A.  beatus  are  discust 
under  the  latter  species.  Figs.  298  and  299,  taken  from  Dr.  Wie- 
land,  represent  the  position  of  the  sulci  on  the  first  left  peripheral 
of  A .  punctatus  and  A.  beatus.  From  these  it  appears  that  the 
width  of  the  first  vertebral  scutes  was  considerably  greater  in  the 
former  than  in  Leidy's  species;  also  that  the  free  border  of  the 
bone  itself  was  wider  in  Marsh's  species  than  in  Leidy's.  As 
regards  the  width  of  the  front  of  the  vertebral  scute,  there  is 
Fig.  zgS.—AJocus  punctatus.    ijjfjle  to  be  variation  in  it,  and  not  much  stress  can  be  placed 

xT   Mter1vidand°^ '■''''*''    °"  '*•     '^^^  specimen  in  the  Philadelphia  Academy  which  the 

writer  is  obliged  to  refer  to  A .  lacer  differs  from  the  type  in  the 
arrangement  of  the  scutes  on  the  first  peripheral. 

Adocus  beatus  (Leidy). 
Plate  34,  figs.  6,  7;   teit-figs.  299-301. 

Eviys  beatus,  Leidy,  Cret.  Reptiles,  U.S.,  in  Stnithson.Cont.  Know!.,  xiv,  1865,  pp.  107,  119,  plate  xviii, 

figs.  1-3. 
Adocus  beatus.  Cope,  Proc.  Acad.  Nat.  Sci.  Phila.  1868,  p.  235;  Cook's  Geol.  New  Jersey,  1868  (1869), 

p.  734;    Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1869,  pp.  129,  233;   Proc.  Amer.  Philos.  Soc,  xi, 

1870,  pp.  296,  547;  Ibid  XII,  1871,  p.  43;  Vert.  Cret.  Form.  West,  1875,  P-  262. — Hay,  Bibliog.  and 

Cat.  Foss.  Vert.  N.  A.,  1902,  p.  444. 

The  type  of  the  present  species  consists  of  the  anterior  half  of  the  first  neural,  the  third  and 
fourth  neurals  complete,  the  proximal  portions  of  the  second  and  third  costals,  the  proximal 
end  of  the  left  first  costal,  and  the  left  first  peripheral.  These  were  obtained  in  the  Cretaceous 
greensand  at  Mullica  Hill,  Gloucester  County,  New  Jersey,  and  were  presented  to  the  Academy 
of  Natural  Science  of  Philadelphia,  by  William  M.  Gabb.  These  remains  are  yet  in  the 
Academy's  collection. 

In  1869  Professor  Cope,  as  cited,  identified  as  belonging  to  this  species  a  plastron  and 
some  portions  of  the  carapace  which  had  been  found  in  the  greensand  at  Medford,  New  Jersey. 
These  bones  are  now  in  the  Cope  collection  at  the  American  Museum  of  Natural  History, 
at  New  York.  A  figure  of  this  plastron  is  here  presented  (plate  34,  fig.  6).  Besides  the 
greater  part  of  the  plastron  there  are  present  fragments  of  several  costals,  and  some  anterior 
peripherals. 

In  1890  Professor  O.  C.  Marsh  (Amer.  Jour.  Sci.,  XL,  p.  178)  described  A.  punctatus. 
Afterwards  Dr.  Baur  (Proc.  Acad.  Nat.  Sci.  Phila.  1891,  p.  428)  affirmed  that  this  species 
is  identical  with  Leidy's  A.  beatus.  Now,  a  comparison  of  Cope's  specimen  with  the  type  of  A. 
punctatus  shows  that  they  are  without  doubt  of  diff"erent  species.  At  the  same  time,  it  is  perhaps 
impossible  to  point  out  characters  which  will  enable  us  to  separate  either  Cope's  or  Marsh's 
specimens  from  Leidy's  imperfect  type.  In  such  a  case  we  must  do  one  of  three  things — 
reject  Leidy's  species  and  its  name,  because  of  its  ambiguous  characters,  giving  a  new  name  to 
Cope's  specimen  and  retaining  Marsh's  specific  name;  accept  Baur's  conclusion,  reducing 
Marsh's  name  to  synonymy  and  renaming  the  Cope  specimen;  or  accept  Cope's  determination 
and  thereby  avoid  any  new  names.  Cope's  turtle  having  come  from  the  same  region  and  level, 
and  having  been  first  determined  as  A.  beatus,  it  appears  to  the  writer  that  the  last  of  the  three 
courses  is  the  best  to  follow.  The  principal  respect  in  which  the  Medford  specimen  differs 
from  Leidy's  type  is  in  the  thickness  of  the  first  peripheral.  In  Leidy's  specimen  (figs.  299, 
300)  this  is  only  15  mm.  thick,  while  that  of  Cope's  is  20  mm.  This  does  not,  however,  decide 
the  question  in  favor  of  Baur's  position,  for  the  type  of  A .  punctatus  also  has  this  bone  20  mm. 
thick.  It  is  not  at  all  improbable  that  the  shell  was  thicker  in  some  individuals  than  in  others. 
Fig.  300  represents  the  same  bone  of  Leidy's  type,  as  the  bone  appears  from  below,  showing  an 
excavation  for  a  process  from  the  nuchal. 


240 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


Neural. 

Length. 

Width. 

Thickness. 

I 

7« 

3> 

7.3-3.1 

1 

4«? 

29? 

12 

3 

5° 

35 

11.5 

4 

46 

33 

11.5 

Marsh's  type  of  J.  punctatus  and  the  Medford  turtle  have  the  posterior  plastral  lobes  of 
the  same  width.  The  length  of  the  whole  plastron  oi  A .  punctatus  is  353  mm.;  that  of  the 
Medford  specimen  about  420  mm.    The  hinder  lobe  of  the  Medford  specimen  (plate  34,  fig.  6) 

■W     is  about  18  mm.  longer  than  that  of  A.  punctatus.    It  is 
also  narrow  and  ends  behind  in  a  blunt  point,  while  that 
oi  A.  punctatus  is  broad  and  the  extremity  is  truncated. 
Plate  34,  fig.  7,  represents  the  first  peripheral  of  the  right 
side  and  a  part  of  the  second,  while  text-fig.  301  repre- 
sents the  first  left  peripheral,  all  from  the  Medford  speci- 
men.   In  this  the  front  of  the  first  vertebral  scute  extends 
somewhat  beyond  the  end  of  the  first  marginal,  while  in 
the  type  (fig.  299)  it  does  not  pass  beyond  the  marginal. 
We  must,  however,  expect  variations  in  this  region,  as  there  are  variations  in  the  same  region 
in  living  turtles.     The  neurals  of  Leidy's  type  have  the  dimensions  given  in  the  table  herewith. 
The  thickness  of  the  second  neural  is  determined  from  the  contiguous  border  of  the  costal. 

The  dimensions  of  the  remains  of  costals  are  shown  in  the 
table  herewith. 

The  anterior  neural  is  irregularly  angular  in  front.  The 
second  appears  to  have  had  the  form  of  the  same  bone  in  the 
type  oi  A.  punctatus.  The  neurals  of  Leidy's  type  are  narrower 
than  those  of//,  punctatus,  but  no  great  stress  can  be  laid  on  the 
difference.  Only  a  fragment  of  the  first  costal  is  present.  The 
second  costal  articulated  with  the  first,  second,  and  third  neurals, 
just  as  in  A.  punctatus.  The  first  peripheral  is  62  mm.  antero-posteriorly,  about  54  mm. 
along  the  free  margin,  and  15  mm.  thick.  Fig.  299,  from  Wieland,  shows  the  form  of  this  bone 
and  the  arrangement  of  the  scutes  on  it.  The  neurals  and  costals  show  the  regular  and 
shallow  pitting  exhibited  by  A.  punctatus  Marsh. 

The  plastron  of  this  species  is  known  only  from  the  specimen  described  by  Cope  (plate  34, 
fig.  6).    The  dimensions  may  be  obtained  from  the  comparative  table  on  page  242.    The  total 


Costal. 

Width. 

Thickness. 

I 
2 
3 

46-50 
62 

6 
114 

11.5 

Figs.  299-301. — Adocus  heatus.     Peripherals.      X^.    After  Wieland. 

299.  First  left  peripheral  of  type. 

300.  First  left  peripheral  of  type,  inferior  surface,  with  section  near  suture  with  second  peripheral. 

Shows  pit  for  process  of  nuchal.    Upper  surface  of  section  toward  right. 

301.  First  left  peripheral  of  Cope's  Medford  specimen.    No.  1138  A.M.N.  H. 

length  may  have  been  greater  than  that  there  given,  since  there  is  an  interval  wanting  in  the 
hyoplastron,  and  since  less  space  has  been  allowed  between  the  hyohypoplastral  suture  and 
the  inguinal  notch  than  between  this  suture  and  the  axillary  notch.  The  bridge,  as  restored, 
has  a  width  of  about  160  mm.  The  sides  of  the  anterior  lobe  are  only  slightly  convex;  the  front 
broad  and  truncated,  its  width  being  about  95  mm.    The  anterior  border  is  obtuse  in  section. 

The  hinder  lobe  is  gradually  reduced  in  width  backward  and  it  ends  obtusely.  As  Cope 
remarkt,  there  is  some  asymmetry  near  the  extremity,  but  this  is  individual.  The  free  borders 
of  this  lobe  are  subacute  and  a  shallow  groove  runs  parallel  with  the  border  on  the  upper  side 
of  the  bones. 

The  sulci  of  the  plastron  are  rather  obscure.  That  of  the  median  line  has  not  been  repre- 
sented in  the  figure.  Probably  it  ran  an  irregular  course,  such  as  is  seen  in  the  other  species. 
The  intergular  scute  is  large  and  it  trespasses  on  the  margin  of  the  entoplastron,  separating 


DERMATEMYDID^.  24I 

widely  the  gulars.  It  was  probably  divided.  The  gulars  are  of  rather  peculiar  form,  extending 
outward  and  backward  toward  the  outer  hinder  angle  of  each  epiplastron.  The  humero- 
pectoral  sulcus  is  so  obscure  that  its  course  is  uncertain,  but  it  appears  to  run  where  indi- 
cated in  the  figure.  If  this  is  correct,  it  did  not  cross  any  part  of  the  entoplastron.  The 
pectoro-abdominal  sulcus  and  the  abdomino-femoral  are  distinct  and  as  shown  in  the  figure. 
The  course  of  the  femoro-anal  is  as  represented  in  the  figure.  Of  the  inframarginal  series, 
only  a  small  portion  of  one  axillary  scute  is  seen.  The  sculpture  of  the  lower  surface  is  hardly 
to  be  determined,  the  result  of  weathering. 

Both  first  peripherals  are  present  (plate  34,  fig.  7;  text-fig.  301).  The  antero-posterior 
length  is  65  mm.;  the  length  along  the  free  border,  64  mm.;  along  the  hinder  border,  about 
half  as  much.  The  thickness,  as  stated,  is  20  mm.  The  upper  surface  of  this  bone  is  gently 
convex;  the  lower  surface  is  strongly  convex  antero-posteriorly.  Close  to  the  anterior  border 
above  there  runs  a  shallow  groove,  so  that  the  free  border  appears  somewhat  everted.  On  the 
lower  surface  the  sutural  face  for  articulation  with  the  nuchal  is  excavated  for  the  short  costi- 
form  process  of  the  latter.  The  same  excavation  appears  in  the  first  peripheral  of  Leidy's 
type  of  the  species  (fig.  300). 

The  marginal  scutes  did  not  extend  upward  quite  half-way  on  the  peripheral.  Only  a 
fragment  of  the  second  peripheral  is  present.  The  form  of  the  nuchal  bone  can  only  be  inferred 
from  the  sutural  edges  of  the  adjoining  first  peripherals.  It  seems  probable  that  its  right  and 
left  sides  made  a  sharper  angle  with  each  other  than  they  do  in  A.  punctatus.  It  is  extremely 
probable  that  the  front  border  of  the  nuchal  measured  between  65  and  70  mm.  The  front  of 
the  first  vertebral  scute  would  then  measure  about  130  mm. 

There  are  present  fragments  of  various  costals  and  bridge  peripherals.  The  proximal  end 
of  a  costal,  probably  the  left  third,  has  a  width  of  50  mm.  and  a  thickness  of  1 1  mm.  The 
sulcus  bounding  laterally  the  two  vertebral  scutes  of  which  it  bears  parts  is  distant  25  mm. 
from  the  suture  made  with  the  neural.  These  vertebrals  were  then  about  80  mm.  wide,  much 
narrower  than  the  first  vertebral.  The  distal  end  of  another  costal  is  60  mm.  wide  and  8  mm. 
thick.  It  is  crost  by  a  sulcus  which  runs  from  17  mm.  to  45  mm.  above  the  lower  or  distal  end. 
A  bridge  peripheral  is  represented  by  the  end  which  joined  the  costal.  It  is  57  mm.  wide  and 
6  mm.  thick.  On  its  inner  surface  is  a  broad,  shallow  groove  for  the  extremity  of  the  rib,  and 
a  portion  of  the  rib  extended  beyond  the  border  of  the  costal  plate  at  least  50  mm.  Another 
fragment,  which  appears  to  be  part  of  a  peripheral  near  one  of  the  buttresses,  indicates  that  a 
rib  sent  its  free  extremity  down  deep  into  the  bone  forming  a  gomphosis,  as  in  Zygoramma. 

The  costals  and  the  peripherals  are  ornamented  with  shallow  pits  separated  by  low, 
rounded  walls,  and  are  arranged  somewhat  in  rows.  On  the  outer  ends  of  the  costals  and 
peripherals  the  sculpture  is  often  obscure. 

Adocus  lacer  sp.  nov. 
Plate  34,  fig.  8;    plate  36,  fig.  i;   text-figs.  301-307. 

The  type  of  this  species  belongs  to  the  Cope  collection  in  the  American  Museum  of  Natural 
History.  Its  number  is  1350.  There  is  no  history  regarding  the  origin  or  the  finder  of  the 
specimen,  but  there  is  no  doubt  that  it  was  obtained  from  the  upper  greensand  bed  of  the 
Cretaceous  of  New  Jersey.  There  is  nothing  to  indicate  to  what  species  Cope  referred  it. 
The  materials  include  the  greater  portion  of  the  plastron,  the  nuchal,  the  three  anterior  periph- 
erals of  both  sides  and  a  small  portion  of  the  left  front  costal. 

The  species  is  characterized  by  a  plastron  (plate  36,  fig.  i)  which  is  elongated  in  proportion 
to  the  width  of  the  base  of  the  hinder  lobe.  The  bridge  likewise  is  longer,  in  relation  to  the 
width  of  the  hinder  lobe  of  the  plastron,  than  in  any  of  the  other  species.  In  width  of  bridge, 
in  relation  to  the  length  of  the  plastron  from  the  entoplastron  to  the  rear  of  the  xiphiplastrals, 
A.  agilis  exceeds  it.  The  hinder  lobe  resembles  most  that  of  the  species  just  named,  but  the 
lateral  borders  are  not  so  uniformly  curved  and  there  is  on  the  upper  surface  a  groove  parallel 
with  the  free  edge.  The  dimensions  of  the  various  parts  are  to  be  obtained  from  the  table 
on  page  242. 

The  anterior  lobe  is  not  represented  in  front  of  the  hyoplastron,  except  by  about  one- 
fourth  of  the  entoplastron.  The  latter  has  had  a  width  of  about  88  mm.  The  free  border  of 
16 


242 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


the  hyoplastron  in  front  of  the  axillary  notch  is  acute,  differing  thus  from  A.  agilis  and  A. 
beatus.  The  hyoplastral  and  the  hypoplastral  portions  of  the  median  suture  are  nearly  equal 
in  extent;  whereas  in  A.  agilis  the  hypoplastral  portion  is  considerably  longer  than  the  hyo- 
plastral part.  The  transverse  suture  between  the  anterior  and  posterior  halves  of  the  plastron 
is  very  coarse,  there  being  alternately  large  pits  and  processes  for  mutual  gomphosial  articu- 
lation. The  form  and  proportions  of  the  hinder  lobe  may  be  determined  from  the  table  on 
this  page  and  from  the  figure.  The  free  borders  are  acute,  with  a  parallel  groove  on  the  upper 
surface.  The  scar  for  the  pubis  resembles  that  of  the  other  species,  but  it  is  more  deeply 
imprest.  Just  in  front  of  the  hinder  border  of  the  xiphiplastrals  and  lying  across  the  midline 
there  is  a  conspicuous  elevation,  the  thickness  of  the  bone  here  being  i6  mm.  In  the  center 
of  the  lobe  the  bone  thins  down  to  about  lo  mm. 

The  pectoral  scutes  are  of  considerably  greater  extent  antero-posteriorly  than  in  A.  agilis, 
68  mm.  as  opposed  to  36  mm.,  the  humero-pectoral  sulcus  swinging  well  forward  on  the  ento- 
plastron.  The  abdominal  scutes  are  larger  than  those  of  any  of  the  five  species  compared 
with  this  one  in  the  table,  the  sulcus  between  them  being  135  mm.  long.  The  femoral  scutes 
also  exceed  those  of  the  other  related  species,  being  100  mm.  in  the  midline.  The  anal  scutes 
are  relatively  short,  75  mm.    There  are  3  inframarginal  scutes  on  the  bridge,  the  middle  one 


Table  of  measurements 

of  species  of 

Adocus. 

A*  beatus. 

A,  agilis. 

A.  syntheticus. 

A.  punctatus. 

A.  lacer. 

A.  pravus. 

T^enpth  of  olastron 

42o± 

454 

356 

450± 

From  hinder  border  of  ento- 

plastron  to  rear  of  plastron 

34o± 

310 

346 

283 

355 

Hyoplastron  on  midline 

IOO± 

95 

R.    85 
L.  115 

80 

125 

no 

Width  of  bridge 

160 

185 

200  ± 

144 

192 

Hypoplastron  on  midline 

'■5 

120 

R.  147 
L.  120 

105 

120 

130 

Length  of  hinder  lobe 

.48 

130 

'45 

130 

140 

Length  of  liphiplastron 

120 

100 

■■5 

100 

"5 

Width  of  plastron  at  bridge. . , 

290 

380     ^-- 

i8o 

285 

Width  of  anterior  lobe  at  base 

160 

2IO± 

190 

180 

Width  of  hinder  lobe  at  base . . 

>75 

177 

230 

176 

177 

Width  of  entoplastron 

88 

9' 

95 

88 

70 

Length  of  entoplastron 

54 

69.5 

70 

Thickness  at  crossing  of  med- 

ian sutures 

"4 

12 

16 

'7 

12 

Thickness    of    epiplastron    at 

symphysis 

■5 

14 

Thickness  of   hyoplastron   in 

front  of  axillary  notch 

'5 

14 

■4 

14 

Thickness   at  front  of  xiphi- 

plastron  in  midline 

17 

16 

18 

'3 

being  107  mm.  long  and  28  mm.  wide.  In  the  figure  the  sulci  are  represented  as  being  broader 
than  they  really  are. 

The  plastron  is  considerably  eroded.  The  lower  surface  is  furnisht  with  numerous  small 
pits,  some  of  them  resembling  pin-holes,  but  to  what  extent  these  are  due  to  weathering  it  is 
difficult  to  say. 

The  anterior  rim  of  the  carapace,  from  one  axillary  notch  to  the  other,  shows  that  at 
these  notches  the  carapace  had  a  width  of  455  mm.  Whether  or  not  the  carapace  expanded 
backward,  as  it  does  in  A.  punctatus,  can  not  now  be  decided.  The  front  (plate  34,  fig.  8) 
is  almost  exactly  an  arc  of  a  circle  whose  radius  is  197  mm.  The  front  of  A .  punctatus  is 
somewhat  truncated.  The  rim  is  thick  and  heavy,  except  that  the  nuchal  bone  is  excavated 
on  its  hinder  surface,  so  that  its  thickness  is  only  14  mm.  At  its  articulation  with  the  first 
peripherals  it  has  increased  to  25  mm.  The  greatest  thickness  of  the  third  peripheral,  just 
in  front  of  the  axillary  notch,  is  40  mm. 

The  upper  surface  of  the  nuchal  and  of  the  anterior  peripherals  is  slightly  convex  from 
above  downward.  The  free  edge  is  rather  thin  and  is  somewhat  reverted,  as  in  A.  punctatus. 
The  lower  side  of  the  peripherals  is  very  convex  from  front  to  back;  that  of  the  nuchal  con- 
cave.    The  free  border  of  the  nuchal  measures  75  mm.     At  its  upper,  or  hinder,  border  it 


DERMATEMYDID^. 


243 


is  92  mm.  wide.  Its  extent  front  to  back  is  75  mm.  Its  hinder  border  is  somewhat  exca- 
vated for  union  with  the  first  neural.  The  free  borders  of  the  three  anterior  peripherals 
measure  each  from  60  mm.  to  65  mm.  The  height  of  the  first  is  65  mm.;  that  of  the 
third,  83  mm. 


Figs.  302-304. — Adocus  lacer.     Entoplastron,  xiphiplastron,  and  peripheral.      X§. 

302.  Entoplastron,  left  half.  303.  Right  xiphiplastron.  304.  First  left  peripheral. 

The  sulci  separating  the  marginal  scutes  from  the  vertebral  and  the  costals  is  not 
far  above  the  free  border  of  the  bones.  If  there  were  a  distinct  nuchal  scute  it  has  been 
effaced  by  a  slight  injury  to  the  bone.  The  first  marginal  is  25  mm.  from  front  to  back. 
The  ^height  of  the  succeeding  ones  increases  until  that  of  the  fourth  is  40  mm.    The  first 


Figs.  305-307. — Adocus  lacer. — Peripherals,      xj. 

305.  Ninth,  tenth,  and  eleventh  peripherals  and  part  of  suprapygal. 

306.  Section  near  hinder  end  of  ninth  peripheral. 

307.  Section  of  eleventh  peripheral  where  it  joined  the  pygal. 

vertebral  scute  has  a  width  from  side  to  side  of  150  mm.     It  probably  had  the  form  found 
in  A.  punctatus. 

In  the  collection  of  the  Philadelphia  Academy  there  is  a  lot  of  bones  of  an  Adocus  which 
is  referred  to  the  present  species.    There  are  no  data  accompanying  the  specimens,  but  there 


244  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

can  be  no  doubt  that  they  were  found  in  the  Cretaceous  greensand  of  New  Jersey.  There 
are  present  the  left  first,  ninth,  tenth,  and  eleventh  peripherals,  a  part  of  the  suprapygal, 
some  fragments  of  costal  bones,  the  left  half  of  the  entoplastron,  the  left  hypoplastron,  and 
the  right  xiphiplastron.  Fig.  302  represents  the  piece  of  the  entoplastron.  When  complete 
it  was  56  mm.  long,  80  mm.  wide,  and  18  mm.  thick  at  the  hinder  border.  The  intergular 
scutes  encroacht  on  the  front  of  it  and  the  pectorals  on  the  hinder  border.  The  hinder  lobe 
was  173  mm.  wide  at  the  base  and  about  135  mm.  long.  The  left  hypoplastron  is  103  mm- 
long.  At  the  midline,  between  the  inguinal  notches,  it  is  28  mm.  thick.  Fig.  303  represents 
the  outline  of  the  right  xiphiplastron,  seen  from  below.  It  agrees  in  form  with  that  of 
the  type  of  the  species,  and  shows  that  the  hinder  end  of  the  plastron  was  broadly  rounded. 
At  the  middle  of  the  suture  with  the  corresponding  hypoplastron  it  is  18  mm.  thick.  There 
was,  near  the  outer  border,  a  stout  process  that  fitted  into  the  hypoplastron.  On  the  upper 
surface  is  a  large  depression  for  the  pubic  bone.  In  the  midline,  at  the  hinder  ends 
of  the  xiphiplastra  there  is  a  considerable  elevation,  and  here  the  thickness  of  the  bone  is 
20  mm. 

Both  the  hypoplastron  and  the  xiphiplastron  are  pitted,  the  latter  most  distinctly.  The 
surface  of  the  entoplastron  is  irregularly  pitted. 

Fig.  304  presents  a  view  of  the  first  left  peripheral,  and  this  may  be  compared  with  that 
o(  A.  heatus  and  that  oi  A .  piinctatus.  It  measures  61  mm.  along  the  free  border  and  68  mm. 
at  right  angles  to  this.  Its  greatest  thickness,  where  it  joins  the  nuchal,  is  20  mm.  It  will  be 
observed  that  the  arrangement  of  the  sulci  differs  from  that  of  the  type  and  resembles  more 
that  of  A.  punctatus.  It  is  to  be  concluded  that  the  scutes  here  were  somewhat  variable  in 
their  development.     The  free  border  of  the  bone  is  somewhat  reverted,  as  in  the  type. 

The  three  hinder  peripherals  are  narrow  and  high  (fig.  305).  The  ninth  has  a  width  of 
65  mm.  and  a  height  of  100  mm.;  the  tenth  a  width  of  60  mm.  and  a  height  of  95  mm.;  the 
eleventh  a  width  of  58  mm.  and  a  height  of  68  mm.  With  the  latter  peripheral  is  a  portion 
of  the  suprapygal.  Evidently,  as  in  A.  punctatus,  the  costo-marginal  sulci  ran  at  some 
distance  above  the  peripherals.  A  part  of  the  fifth  vertebral  scute  appears  high  up  on  the 
suprapygal.  Figs.  306  and  307  represent  the  hinder  sutural  faces  of  the  ninth  and  eleventh 
peripherals. 

On  the  upper  borders  of  the  ninth  and  tenth  peripherals  are  seen  remains  of  the  extrem- 
ities of  the  ribs  of  the  seventh  and  eighth  costals,  which  extend  down  into  the  peripherals. 
On  fragments  of  the  bridge  peripherals  are  seen  the  rib-ends  lying  in  shallow  grooves  on  the 
inner  surfaces,  sometimes  extending  downward  as  much  as  50  mm.  Other  fragments  of 
bridge  peripherals  show  that  the  transition  from  the  upper  to  the  lower  surfaces  was  rather 
abrupt,  there  being  a  decided  but  rounded  angle  where  the  turn  was  made. 

The  peripherals  and  the  costals  are  all  ornamented  with  pits,  arranged  mostly  in  oblique 
rows.     There  are  about  5  pits  in  a  line  6  mm.  long. 

Adocus  syntheticus  Cope. 
Plate  36,  fig.  2. 

Adocus  syntheticus,  CoPE,  Proc.  Amer.  Philos.  Soc,  xi,  1870,  p.  515  (name  only);  Ibid.,  p.  548;  Op. 
cit.,  xn,  1871,  p.  44;  Vert.  Cret.  Form.  West,  1875,  p.  262. — Hay,  Bibliog.  and  Cat.  Foss.  Vert. 
N.  A.,  1902,  p.  444- 

Professor  Cope's  first  reference  to  this  species  did  not  bear  with  it  any  description.  The 
species  was  said  to  be  based  on  a  plastron  lacking  the  entoplastron,  the  right  epiplastron  and 
the  right  hypoplastron,  a  peripheral  bone  from  the  bridge,  2  imperfect  costals,  and  some 
smaller  fragments.  This  type  is  now  in  the  American  Museum  of  Natural  History,  and  has 
the  number  1466.  All  the  parts  originally  described  are  present,  except  the  hinder  extremity 
of  the  right  xiphiplastron.  The  "marginal  from  the  bridge"  is  a  part  of  the  right  hypoplastron. 
The  specimen  was  found  in  the  upper  bed  of  the  Cretaceous  greensand,  at  Barnesboro,  New 
Jersey. 

Professor  Cope  states  that  the  length  of  the  plastron  is  484  mm.  This  is  probably  a  mis- 
print for  454  mm.,  which  appears  to  be  nearer  to  the  correct  length.    The  plastron  as  a  whole 


DERMATEMYDID^.  245 

is  broad  and  flat.  It  was  truncated  in  front  and  broadly  rounded  behind.  With  only  the 
known  materials  it  is  impossible  to  state  accurately  the  length  and  width  of  the  anterior  lobe. 
The  anterior,  truncated  end  had  a  width  of  about  80  mm.  The  two  epiplastrals  joined  along 
the  midline  for  about  37  mm.  The  anterior  free  border  of  the  epiplastral  is  thick,  but  the 
lateral  border  thins  down  backward  to  an  edge.  The  size  and  form  of  the  entoplastron  can  be 
judged  from  the  surrounding  bones.  Cope  gives  the  length  as  70  mm.  and  the  width  as  95  mm., 
which  dimensions  appear  to  be  correct. 

As  will  be  seen  from  the  plate  36,  fig.  2,  the  sutures  are  extremely  irregular  in  their  course. 
The  entoplastral  notch  in  thfi  hyoplastrals  is  not  symmetrical.  On  account  of  unsymmetrical 
development,  the  right  hypoplastron  articulated  with  both  hyoplastra,  the  left  hypoplastron, 
and  with  both  xiphiplastra.  The  right  hypoplastron  is  thus  27  mm.  longer  than  the  left. 
These  and  other  measurements  are  presented  in  the  table  on  page  242. 

Professor  Cope  states  that  the  length  of  the  hinder  lobe  of  the  plastron  is  155  mm.;  the 
width,  230  mm.  He  also  says  that  a  fragment  of  the  bridge  displays  the  axillary  and  part  of 
the  anterior  inframarginal  scutes;  but  to  the  present  writer  this  fragment  seems  rather  to  belong 
to  the  inguinal  region  of  the  right  side.  The  reason  for  this  identification  is  found  in  the  fact 
that  in  A .punctatus  and  A.lacer  the  pectoro-abdominal  sulcus  starts  off  from  the  sulcus  bound- 
ing the  axillary  scute  on  the  mesial  side,  while  the  abdomino-femoral  sulcus  does  not  come  into 
contact  with  the  inguinal  scute  on  the  lower  side  of  the  plastron.  In  the  fragment  under  con- 
sideration the  arrangement  of  the  sulci  conforms  to  that  of  the  region  of  the  inguinal  notch. 
On  placing  this  fragment  in  this  region  the  hinder  lobe  is  found  to  have  a  length  of  145  mm. 
and  a  width  of  230  mm.,  being  unusually  short  in  proportion  to  the  width. 

The  central  portion  of  the  hinder  lobe  is  thick,  but  the  free  borders  are  thin  and  acute,  the 
thickness  becoming  gradually  reduced.  On  the  upper  side  of  the  xiphiplastra  there  is  a 
prominent  curved  ridge,  and  nearer  the  midline  a  deep  depression.  These  mark  the  attach- 
ment of  the  pubic  bone.    A  rounded  knob  marks  the  position  of  the  ischium. 

The  fragment  of  the  bridge  which  has  already  been  referred  to  as  belonging  properly  to 
the  inguinal  region  bears  on  its  upper,  or  inner,  surface  a  strong  ridge  which  rises  to  form  a 
buttress  against  the  carapace.  The  inner  border  of  the  buttress  is  sharp.  There  is  another 
fragment  of  the  bridge  present,  the  outer  end  of  the  right  hyoplastral.  This  does  not  reach 
so  far  forward  as  the  axillary  notch;  backward  it  extends  to  the  hyohypoplastral  suture. 

The  sulci  of  the  plastron  are  mostly  very  distinct,  but  not  broad  nor  deeply  imprest.  The 
longitudinal  median  sulcus  runs  a  meandering  course,  but  anteriorly  it  is  too  obscure  to  be 
traced.  There  was  a  large  intergular,  probably  divided.  Its  width  was  about  40  mm.  Its 
hinder  border  encroacht  slightly  on  the  entoplastron.  The  gulars  were  widely  separated  b\' 
the  intergular.  The  pectorals  met  along  the  midline  for  about  42  mm.  and  overlapt  slightly 
the  entoplastron.  The  abdominals  occupied  135  mm.  of  the  midline;  the  femorals,  about 
82  mm.;  and  the  anals,  also  about  82  mm.  The  inframarginal  scutes  were  large,  the  middle 
one  about  135  mm.  long  and  50  mm.  broad.  Outside  of  the  inframarginals  are  portions  of 
3  marginals,  the  fifth,  sixth,  and  seventh.  The  sixth  is  137  mm.  broad,  running  along  the  middle 
inframarginal  for  the  entire  length  of  the  latter. 

The  surface  of  the  plastron  is  finely  granulated,  vermiculated,  or  pitted,  but  no  definite 
pattern  of  sculpture  can  be  made  out.  On  each  side  of  most  of  the  sutures  there  is  a  band  of 
fine  parallel  grooves. 

Portions  of  2  costals  are  present,  showing  the  proximal  ends.  One  of  these  is  55  mm.  wide 
at  the  proximal  end  and  8  mm.  thick.  On  the  inner  surface  there  is  seen  the  rudimentary 
rib-head.  The  other  costal,  probably  the  left  seventh,  is  38  mm.  wide  proximally,  but  it  widens 
distaily.  It  is  notcht  proximally  for  a  neural,  probably  the  sixth,  and  behind  the  latter  it 
apparently  met  the  corresponding  costal  of  the  opposite  side.  The  surfaces  are  smooth  and 
present  no  distinct  evidences  of  sulci. 

The  form  of  the  plastron  of  this  species  is  most  like  that  oi  A.  agilis,  but  it  differs  from  that 
of  the  latter  in  being  relatively  shorter,  in  having  the  lateral  borders  more  convergent  from  the 
base,  and  the  bone  does  not  thicken  so  rapidly  from  the  acute  free  edges.  The  sculpture  of  the 
plastron  of  A.  syntheticus  is  quite  different  from  that  of  A.  agilis,  and  the  inframarginal 
scutes  are  much  broader. 


246  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

Adocus  agilis  Cope. 

Plate  36,  fig.  3. 

Adocus  agilis,  CoPE,  Proc.  Acad.  Nat.  Sci.  Phila.  1868,  p.  235;  Cook's  Geol.  New  Jersey,  1868  (1869), 
p.  734;  Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1869,  pp.  ii,  233,  234;  Proc.  Amer.  Philos.  Soc, 
XI,  1870,  pp.  296,  297,  549;  Op.  cit.,  XII,  1871,  p.  44;  Vert.  Cret.  Form.  We.st,  1875,  p.  262. — Hay, 
Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  444. 

The  type  of  this  species  is  in  the  American  Museum  of  Natural  History  and  bears  the 
number  1135.  It  was  collected  in  the  upper  bed  of  the  Cretaceous  greensand  of  New  Jersey, 
at  Barnesboro. 

The  only  portion  of  the  animal  represented  is  the  plastron  (plate  36,  fig.  3)  and  this  is  not 
complete.  Cope  states  in  his  description  that  the  extremities  of  both  lobes  are  broken  off;  but 
at  present  the  hinder  lobe  is  complete  on  the  right  side.  The  front  of  the  anterior  lobe  being 
gone,  the  total  length  of  the  plastron  can  not  be  determined  with  exactness.  Cope  estimated  it 
at  450  mm.;  but  this  is  certainly  an  error;  it  was  probably  not  greater  than  400  mm.,  and 
more  probably  about  390  mm. 

The  plastron  is  short  and  broad,  but  yields  in  these  respects  to  that  of  A.  punctatus.  The 
dimensions  may  be  obtained  from  the  table  on  page  242.  The  plastron  is  very  flat,  even  out  to 
the  suture  with  the  peripherals  of  the  bridge,  but  it  is  possible  that  the  bridge  has  been  distorted 
through  pressure.  The  entoplastron  has  its  anterior  angle  now  broken  off,  but  Cope  gave  its 
length  as  69.5  mm.  Its  width  is  91  mm.  The  free  edge  of  the  hyoplastron,  just  in  front  of  the 
axillary  notch,  is  rounded  in  section.  The  bridge  is,  relatively  to  the  length  of  the  plastron 
behind  the  entoplastron,  longer  than  in  any  species  with  which  it  is  compared  on  page  242. 

From  the  inguinal  notch  the  free  borders  of  the  hinder  lobe  curve  gradually  to  the  midline 
behind.  These  borders  are  acute,  and  from  them  the  bone  thickens  rather  rapidly  and  without 
the  intervention  of  a  groove  on  the  upper  surface.  The  center  of  the  lobe  has  no  depression 
such  as  we  find  in  A.  lacer  and  to  a  less  extent  in  A.  beatus.  On  the  hinder  half  of.the  upper 
surface  of  each  xiphiplastron  there  is  a  large  curved  depression  which  marks  the  place  of 
articulation  of  the  pubis.    It  is  not  so  deeply  imprest  as  it  '\s\n  A .  lacer. 

Cope  gave,  as  one  character  separating  this  species  from  the  others  then  described,  the 
thinness  of  the  bones;    but  they  appear  to  be  only  a  little  thinner  than  those  of  A.  beatus. 

The  hyoplastron  just  behind  the  entoplastron  is  13  mm.,  that  oi  A.  beatus,  14  mm.;  just 
in  front  of  the  axillary  notch,  14  mm.,  that  of//,  beatus,  17  mm.;  medially  at  the  front  of  the 
xiphiplastron,  16  mm.,  in  A.  beatus,  17  mm. 

The  humero-pectoral  sulcus  falls  behind  the  entoplastron.  The  abdominal  scutes  meet 
along  the  midline  for  a  distance  of  105  mm.;  the  femorals,  87  mm.;  the  anals,  76  mm.  The 
inframarginals  on  the  bridge  are  long  and  narrow,  the  middle  one  being  80  mm.  long  and 
16  mm.  broad.  The  median  longitudinal  sulcus  runs  a  very  irregular  course,  especially  in  the 
hinder  half  of  the  plastron. 

The  whole  lower  surface  of  the  plastron  is  ornamented  with  a  sculpture  which  consists 
of  very  shallow,  somewhat  elongated  depressions  separated  by  low  rounded  walls.  The  pits 
alternate  somewhat  and  are  arranged  more  or  less  in  rows.  These  run  usually  in  a  longitudinal 
direction.  The  sculpture  is  much  like  that  of  A.  beatus  and  A.  punctatus,  and  reminds  us  of 
Cope's  description  of  that  of  Basilemys  imbrtcarta,  but  the  pits  are  not  nearly  so  deep  as  in  the 
latter  species. 

Adocus  pravus  Leidy. 

Emys  pravus,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1856,  p.  303;   Smithson.  Contrib.  Knowl.,  xiv.,  art. 

vi,  1865,  pp.  108,  120,  plate  xix,  fig.  i. 
Adocus  pravus.  Cope,  Proc.  Acad.  Nat.  Sci.  Phila.  1868,  p.  235;  Cook's  Geol.  New  Jersey,  1868  (1869), 

p.  734;    Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1870,  pp.  129,  233,  234;    Proc.  Amer.  Philos.  Soc, 

XI,  1870,  p.  297;  Ibid.,  xii,  1871,  p.  44;  Vert.  Cret.  Form.  West,  1875,  p.  262. — Hay,  Bibliog.  and 

Cat.  Foss.  Vert.  N.  A.,  1902,  p.  444. 
Emys  parva,  Maack,  Palaeontographica,  xvill,  1869,  p.  278. 

The  present  species  was  discovered  by  Professor  George  H.  Cook,  State  Geologist  of  New 
Jersey,  in  the  upper  bed  of  Cretaceous  greensand  at  Tinton  Falls,  Monmouth  County,  New 
Jersey,  and  was  described  by  Dr.  Joseph  Leidy.    Originally  the  type  consisted  of  most  of  the 


DERMATEMYDID^.  247 

left  hyoplastron,  a  large  part  of  the  right  hypoplastron,  and  the  hinder  ends  of  both  xiphi- 
plastra.     Of  these,  there  is  now   in  the  collection  at  Rutgers  College  only  the  hyoplastron. 

The  species  is  characterized  by  the  thinness  of  the  bones,  being  approacht  in  this  respect 
only  by  A.  agilis.  The  hyoplastron  has  a  thickness  varying  from  lo  mm.  to  12  mm.  Accord- 
ing to  Leidy  the  hypoplastron  varies  in  thickness  from  10  to  14.5  mm. 

From  the  portion  of  the  hyoplastron  present  it  appears  that  the  width  of  the  anterior  lobe 
at  the  base  was  about  180  mm.  The  hyoplastral  bones  joined  along  the  midline  a  distance  of 
about  no  mm.  The  entoplastron  had  an  approximate  width  of  65  mm.  and  extended  back- 
ward behind  the  hyoepiplastral  sutures  about  40  mm.  A  sulcus,  the  humero-pectoral,  crosses 
the  plastron  7  mm.  behind  the  entoplastron  and  is  directed  slightly  backward  on  its  way  out- 
ward. The  free  border  of  the  lobe  is  subacute.  All  the  sutures  of  the  hyoplastron  appear  to 
have  been  close  and  smooth  when  viewed  from  below;  but,  seen  from  above,  they  were  coarse 
and  jagged. 

The  hypoplastra  are  stated  by  Leidy  to  have  extended  along  the  midline  5  inches;  accord- 
ing to  his  figure,  130  mm.  The  hinder  end  of  the  plastron  appears  to  have  been  narrowed,  as 
in  A .  beatus. 

This  species  seems  to  have  most  resembled  A.  agilis;  but  the  entoplastron  of  the  latter  is 
considerably  broader,  less  abruptly  rounded,  and  the  notch  was  more  open.  In  A.  syntheticus 
and  A .  punctatus  the  humero-pectoral  sulcus  crosses  on  the  entoplastron. 

This  species  differs  from  Cope's  specimen  oi  A .  beatus,  from  Medford,  in  having  a  narrower 
entoplastron.  In  the  latter  the  width  of  this  bone  was  about  equal  to  the  length  of  the  suture 
between  the  right  and  left  hyoplastra.  In  A.  pravus  the  width  was  equal  to  only  two-thirds 
the  suture  between  the  hyoplastra.  In  other  respects  the  two  species,  so  far  as  known,  appear 
to  agree.  Altho  Leidy  has  restored  in  outline  the  anterior  lobe  of  A.  pravus  as  being  very 
narrow,  it  may  in  reality  have  been  much  broader. 

Adocus?  lineolatus  Cope. 

Figs.  308,  309. 

Adocus?  lineolatus.  Cope,  Bull.  U.  S.  Geol.  and  Geog.  Surv.  Terrs.,  i,  No.  2,  1874,  p.  30;  Ann.  Report 

U.  S.  Geol.  and  Geog.    Surv.  Terrs.,  1873  (1874),  p.  454;    Vert.  Cret.   Foim.  West,  1875,  p. 

92. — Lambe,  Contrib.  Canad.  Palaeont.,  in  (410),  1902,  p.  38. 
Adocus  lineolatus.  Cope,  Vert.  Cret.  Form.  West,  1875,  p.  263,  plate  vi,  figs.  11,  12. — Hatcher,  Bull. 

U.  S.  Geol.  Surv.  No.  257,  1 905,  p.  75. 
Compsemys  lineolatus,  CoPE,  Bull.  U.  S.  Geol.  and  Geog.  Surv.  Terrs.,  Ill,  1877,  p.  573. — Hay,  Bibliog. 

and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  437. 

Of  the  present  species  very  little  is  known.  The  name  is  based  on  2  fragments  which  were 
collected  by  Professor  Cope,  in  northeastern  Colorado.  From  Whitman  Cross  (Monogr.  U.  S. 
Geol.  Surv.,  xxvii,  1896,  p.  244)  we  learn  that  Cope  communicated  the  fact  that  these  and 
some  other  fossils  had  been  collected  at  some  point  not  designated  on  Bijou  Creek. 

Cross  is  of  the  opinion  that  these  fossils  came  from  what  are  called  by  him  the  Arapahoe 
beds,  a  formation  overlying  the  Laramie.  Cope's  type  of  his  Adocus?  lineolatus  is  now  in  the 
American  Museum  of  Natural  History  and  has  the  number  1844.  Cope's  figures  represent 
well  the  specimens;  but  since  they  have  been  figured  the  surface  has  been  scraped  from  the 
neural,  so  that  its  sculpture  no  longer  appears.  That  of  the  fragment  of  plastron  remains.  It 
is  obscure,  but  consists  of  elongated,  very  shallow  pits,  four  or  five  in  a  line  5  mm.  long,  and 
arranged  more  or  less  in  rows  and  separated  by  low  narrow  ridges.  The  neural  has  a  maxi- 
mum width  of  28  mm.  and  a  thickness  of  7  mm.  The  plastral  bone  is  8  mm.  thick  at  the 
sutural  border.  This  suture  is  coarse  and,  as  Cope  says,  has  a  median  serrate  keel,  with  pits  on 
each  side  of  it  for  the  reception  of  processes  from  the  bone  with  which  it  articulated. 

Cope  stated  that  the  species  comes  also  from  the  mouth  of  the  Big  Horn  River,  but  the 
present  writer  does  not  know  of  any  specimens  on  which  this  identification  was  based.  Cope 
likewise  includes  the  species  in  his  list  of  Judith  River  species.  Lambe,  as  cited,  reports  it 
from  the  Belly  River  beds  on  Red  Deer  River,  Alberta,  British  America.  His  specimens  too 
were  fragmentary.  Specimens  with  a  sculpture  very  similar  have  been  brought  to  the  American 
Museum  of  Natural  History  from  the  Laramie  beds  of  Montana.     These  were  collected  by 


248  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

Mr.  Barnum  Brown,  on  Hell  Creek,  Montana.  Fragments  of  costals  scarcely,  if  at  all,  to 
be  distinguisht  from  them  are  found  in  the  collection  made  in  the  Judith  River  region  for 
Professor  Cope,  by  C.  H.  Sternberg,  in  1876.  It  is  the  writer's  opinion  that  it  is  unsafe  to 
identify  as  belonging  to  Adocus  lineolatus  specimens  from  the  Judith  River  and  the  Laramie 
beds  before  far  better  materials  of  the  species  have  been  collected  from  the  type  locality.  And 
when  these  better  materials  have  been  secured  from  Bijou  Creek,  better  specimens  than  yet 
obtained  must  be  secured  from  the  other  formations  mentioned.  It  is  improbable  that  the 
same  species  continued  from  the  Judith  River  epoch  to  the  Arapahoe  epoch.  Meanwhile, 
even  good  fragments  are  worth  preserving. 

The  specimen  referred  to  above  as  having  been  collected  by  Sternberg  from  the  Judith 
River  region  forms  No.  6105  of  the  American  Museum.  It  belonged  to  the  third  or  the  fifth 
costal.  Its  width  is  32  mm.;  its  thickness,  only  3.5  mm.  There  is  no  thickening  along  the 
middle  on  the  under  side  corresponding  to  the  rib.  The  outer  surface  is  crost  by  the  costo- 
vertebral sulcus.  The  ornamentation  resembles  in  pattern  that  of  Cope's  Compsemys  im- 
bricaria  {Basilemys  imbricaria),  and  Cope  has  so  labeled  the  bone;  but  the  size  of  the  areolae  is 
considerably  smaller,  there  being  4  pits  in  a  line  5  mm.  long,  instead  of  3  or  less.  The  ridges 
between  the  areolae  are  low  and  run  at  right  angles  with  the  sutural  borders  of  the  bone. 

A  fragment  of  a  costal  from  Hell  Creek,  Montana,  collected  by  Mr.  Barnum  Brown,  is 
catalogged  under  the  number  1014  of  the  American  Museum.  The  costal  is  36  mm.  wide 
and  5  mm.  thick  .  The  sculpture  is  similar  to  that  of  the  Judith  River  specimen  just 
described,  but  is  more  obscure. 

A  peripheral,  the  second  of  the  left  side,  has  the  number  1014,  but  it  belonged  to  a  much 
larger  individual.    It  is  represented  by  figs.  308  and  309.    The  bone  is  55  mm.  high,  48  mm. 

along  jthe  free  border,  and  32  mm.  along  the 
costal  border.  Fig.  309  represents  the  border 
joining  the  first  peripheral,  the  greatest  thick- 
ness being  16  mm.  The  sutural  border  for  the 
third  peripheral  has  a  maximum  thickness  of 
309.  24  mm.  The  sculpture  has  the  pattern  and  the 
fineness  ascribed  to  the  costal.  It  resembles 
greatly  that  of  the  fragments   numbered  6103 

f.^o  „Q  .„,.,«^  J  J  r  It,  P„,:.,i,  A.  M.  N.  H.  and  described  under  Basilemys 
r  IGS.  300  AND  309. — Adocus  Itneolatus.    reripn-      ...  -' 

eral  and  section.   Xj.  No.  1014  A.  M.  N.  H.       tmbricarta. 

No.  6107  A.  M.  N.  H.  includes  a  fragment 

308.  Second  left  peripheral  ^f  ^  ^^^^^j     j^^^  ^^^  another  of  a  plastral  bone 

305.  Section  of  same  peripheral  at  union  with  third.  »  ^  r      n      r  A  -o 

which  were  collected  for  Professor  Cope,  m  1877, 
by  Mr.  J.  C.  Isaac,  in  the  Laramie  of  Converse  County,  Wyoming.  The  sculpture  of  these 
bones  resembles  closely  that  of  ^.  lineolatus,  type. 

Genus  AGOMPHUS  Cope. 

Shell  thick  and  heavy  in  the  known  species.  Free  borders  of  the  carapace  thickened  and 
obtuse.  Exposed  surfaces  of  the  shell  not  pitted.  Hinder  marginal  scutes  not  rising  on  the 
costal  bones,  except  slightly  in  one  species.  Inframarginal  scutes  present.  The  pectoral 
scutes  extending  forward  to  the  hinder  end  of  the  epiplastrals.  Intergulars  not  known.  Nuchal 
with  costiform  processes.    Rib-heads  more  strongly  developt  than  in  Adocus. 

Type:    A gomphus  turgidus  Cope. 

The  genus  Agomphus  was  founded  by  Cope  in  1871  (Proc.  Amer.  Philos.  Soc,  xii,  p.  46) 
having  A.  turgidus  as  the  type.  The  only  character  given  was  the  apparent  lack  of  gomphosis 
between  the  costals  and  the  peripherals;  an  insufficient  character,  if  a  true  one.  In  1882 
(Proc.  Amer.  Philos.  Soc,  xx,  p.  145)  Cope  placed  Agomphus  with  Dermatemys  in  the  Emy- 
didas,  characterizing  it  as  possessing  2  anal  marginal  scutes,  a  series  of  inframarginals,  and 
with  the  lobes  of  the  plastron  wide.  The  same  views  are  repeated  in  that  author's  Vertebrata 
of  the  Tertiary  Formations  of  the  West,  in  1884.  In  both  the  publications  referred  to,  the 
genus  Amphiemys  was  placed  among  the  Adocidae.  Baur  in  1888  (Zool.  Anzeiger,  XI,  p.  595) 
reduced  Amphiemys  to  the  position  of  a  synonym  of  Agomphus  and  arranged  the  latter  under 


dermatemydidj*.  249 

the  Adocidae.  In  1891  (Proc.  Acad.  Nat.  Sci.  Phila.,  p.  429)  Baur  retains  Agomphus  in  the 
Adocida;  and  gives  as  its  distinguishing  characters  the  narrow  lobes  of  the  plastron  and  the 
shorter  bridge.  He  states  too  that  it  has  costiform  processes  which  reach  the  second  peripheral, 
piercing  the  first. 

The  general  term  of  the  shell  of  the  species  of  this  genus  is  indicated  by  that  of  A.  tardus 
Wieland. 

Key  to  the  Species  of  Agomphus. 

A^.  Upper  Cretaceous  species. 

a'.  With  the  costo-peripheral  sulci,  so  far  as  known,  confined  to  the  peripheral   bones. 

1.  Plastron  nearly  flat  transversely;    entoplastron  broadly  rounded  behind;    pectoro- 

abdominal  sulcus  much  nearer  the  hyohypoplastral  suture  than  to  entoplastron; 
costo-marginal  sulci  above  middle  of  peripheral  bones;  costal  border  of  peripherals 
much  thinner  than  maximum  thickness turgidus 

2.  Plastron  strongly  convex  transversely;    costo-marginal  sulci  below  middle  of  periph- 

erals     petrosus 

3.  Like  petrosus,  but  plastron  not  so  convex ;    costo-marginal   sulci  above   middle  of 

peripherals;  costal  border  of  peripherals  not  much  thinner  than  maximum  thick- 
ness    tardus 

4.  Entoplastron   pointed   behind;    pectoro-abdominal    sulcus  nearer  hyohypoplastral 

suture  than  to  entoplastron  ;  suture  between  the  hyoplastra  0.25  of  the  hyohypo- 
plastral suture pectoralis 

5.  Entoplastron  truncated  behind;   pectoro-abdominal  sulcus  nearer  entoplastron  than 

to  hyohypoplastral   suture firmus 

a^.  Costo-peripheral  sulci  of  nth  and  12th  marginal  scutes  rising  above  the  peripherals. 
I.  Entoplastron  pointed  behind;    suture  between  hyoplastrals  0.35   of  the  hyohypo- 
plastral suture masculinus 

A^.  Early  Tertiary  species. 

I.  With  hinder  lobe  of  plastron  much  narrowed  behind oxysternum 

Agomphus  turgidus  Cope. 
Plate  37,  figs.  1-5;   teit-fig.  310. 

Emys  turgidus,  Cope,  Ext.  Batrach.,  Reptilia,  Aves    N.  A.,  1869,   pp.  125,  127. —  .?Wieland,  Amer. 

Jour.  Sci.  (4),  XX,  1905,  p.  440,  fig.  9,  in  part. 
Agomphus  turgidus.  Cope,  Proc.  Amer.  Philos.  Soc,  xil,  1871,  p.  46;   Vert.  Cret.  Form.  West,  1875,  p. 

262. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  445. 

This  species,  the  type  of  the  genus  Agomphus,  is  based  on  portions  of  the  skeleton  which 
were  obtained  from  the  upper  greensand  bed  of  the  Cretaceous  of  New  Jersey.  The  materials 
consist  of  both  hyoplastra  somewhat  damaged;  the  entoplastron;  the  fourth  neural;  the 
proximal  ends  of  the  third,  fourth,  fifth,  and  sixth  costals  of  the  left  side,  and  of  the  third,  fourth 
and  sixth  of  the  right  side;  some  fragments  representing  the  distal  ends  of  costals;  and  four 
peripherals,  one  from  the  bridge.  The  specimen  is  now  in  the  Cope  collection  in  the  American 
Museum  of  Natural  History,  and  bears  the  number  148 1. 

The  portion  of  the  plastron  (plate  37,  fig.  i)  preserved  has  been  considerably  eroded. 
The  epiplastrals  being  gone,  nothing  is  known  regarding  the  form  of  the  front  of  the  plastron. 
The  front  lobe  had  a  width  of  90  mm.  at  the  base.  The  free  border,  as  far  as  represented,  is 
thin  and  rounded  in  section,  and  a  shallow  groove  runs  parallel  with  it  on  the  upper  side. 
Toward  the  midline  the  bone  thickens  rapidly,  and  at  the  hinder  border  of  the  entoplastron  it 
is  14  mm.  thick.  This  increases  to  17  mm.  at  the  crossing  of  the  median  longitudinal  and 
transverse  sutures.  The  entoplastron  is  rather  pointed  in  front,  broad  and  rounded  behind. 
It  is  slightly  broader  than  long,  thin  in  front  (6  mm.)  and  thick  behind  (14  mm.). 

The  transverse  suture  behind  the  hyoplastrals  is  somewhat  irregular  in  direction.  The 
denticulations  are  fine,  but  there  are  some  grooves  and  keels  near  the  midline. 

Professor  Cope  states  that  only  the  longitudinal  median  sulcus  is  to  be  made  out.  Yet  to 
the  present  writer  it  seems  clear  that  there  is  one  which  crosses  the  entoplastron,  the  humero- 
pectoral,  and  another  which  crosses  the  hinder  ends  of  the  hyoplastrals,  the  pectoro-abdom- 
inals.     These  are  in  exactly  the  positions  of  the  corresponding  sulci  in  A.  pectomhs.    The 


250  FOSSIL    TURTLKS    OF    NORTH    AMERICA. 

surface  of  the  plastron  appears  to  have  been  somewhat  uneven,  but  no  definite  pattern  of 
sculpture  can  be  made  out. 

The  fourth  neural  (plate  37,  fig.  5)  has  a  length  of  27  mm.,  a  width  of  about  24  mm.,  and 
a  thickness  of  11  mm.  The  costals  at  the  proximal  ends  are  as  thick  as  the  neurals,  but  they 
rapidly  become  thinner,  so  that  at  a  distance  of  30  mm.  from  the  neurals  a  costal  is  only  5.5  mm. 
thick;  and  this  thickness  is  maintained  to  the  distal  ends.  The  capitula  of  the  ribs  are  well 
developt.  The  sulci  limiting  laterally  the  vertebral  scutes  are  deeply  and  sharply  imprest. 
These  vertebral  scutes  were  rather  narrow,  about  43  mm.  wide.  The  third  vertebral  has  a 
length  of  60  mm.    The  surface  of  the  bone  is  finely  striated  longitudinally. 

Plate  37,  fig.  4,  represents  3  peripherals  which  appear  to  have  had  the  positions  assigned 
to  them,  the  eighth,  ninth,  and  tenth  of  right  side,  but  possibly  the  ninth,  tenth,  and  eleventh. 
The  one  seen  on  the  right  of  the  figure  is  the  anterior,  but  it  did  not  articulate  with  the 
hypoplastron.  Each  has  an  extreme  thickness  of  about  11  mm.  The  exterior  surface  is  con- 
cave vertically,  while  the  inner  surface  is  strongly  convex.  Fig.  310  is  a  section  through  the 
middle  one  of  the  three.  Altho  the  free  edge  of  the  series  is  somewhat  eroded,  it  evidently  was 
rounded.  Further  forward  this  edge  appears  to  have  been  more  angulated,  until,  as  represented 
by  one  of  the  bridge  peripherals,  the  upper  side  of  the  shell  made  abruptly  an  angle  of  about 
45°  with  the  lower  side.  The  marginal  scutes  of  this  species  were  confined  to  the  peripheral 
bones,  instead  of  extending  upward  on  the  costals.  As  shown  in  the  figures,  the  costal  scutes 
come  down  well  on  the  peripherals. 

The  carapace  of  this  species  had  a  length  of  about  265  mm. 

In  the  Cope  collection  at  the  American  Museum  there  is  a  pair  of  hyoplastrals.  No.  1479 
(plate  37,  fig.  2),  which  evidently  belongs  to  this  species  and  which  is  labeled  as  having  been 

found  at  Mount  Holly,  New  Jersey,  in  1870.  It  has  the  size  of 
the  corresponding  bones  of  the  type,  but  it  is  considerably 
thicker,  being  20  mm.  just  behind  the  entoplastral  notch  and 
also  at  the  hinder  border  of  the  bones  near  the  midline.  About 
one-third  the  distance  from  the  notch  toward  the  rear  the  thick- 
ness is  22  mm.    This  specimen  displays  the  pectoro-abdominal 

.  ,  ■ ,  sulcus  and  a  portion  of  the  inframarginal  scutes  on  the  left 

riG.  710. — Asompnus  turgiaus.  -jt-ii  ^lu  j  ■      j     ^ 

„  -^ .  *     '^  .    ,      *  .  ,  side.      The  latter  appear  to  have  been  arranged  as  m  A.  pec- 

bection  across  ninth  periph-  ,.       _,,  i-  1         •      1  1  1  l 

eraloftvpe      Xj  torahs.     The  median  sulcus  is  obscure,  but  what  appears  to  be 

a  portion  of  it  is  seen  on  the  right  side  running  backward 

from  the  transverse  sulcus,  while  apparently  another  short  branch  is  seen  on  the  left  side. 

The  surface  of  the  plastron  contains  several  large  shallow  pits  and  long  grooves,  as  shown 

in  the  figure  cited.    It  is  evident  that  these  have  been  made  during  the  life  of  the  animal,  the 

result  probably  of  some  disease.    Fig.  3  of  plate  37  represents  the  same  hyoplastrals  seen  from 

the  front. 

Agomphus  petrosus  Cope. 

Plate  36,  fig.  4;   plate  37,  figs.  6,  7;    text-figs.  311-313. 

Adocus  petrosus.  Cope,  Proc.  Acad.  Nat.  Sci.  Phila.  1868,  p.  236;   Cook's  Geol.  New  Jersey,  App.  B, 

1868  (1869),  p.  734;    Proc.  Amer.  Phiios.  Soc,  xi,  1870,  p.  295. 
Emys  petrosus,  CoPE,  Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1869,  pp.  125,  126. 
Agomphus  petrosus.  Cope,  Proc.  Amer.  Phiios.  Soc,  xii,  1871,  p.  46;    Ann.  Report  U.  S.  Geol.  Surv. 

Terrs.,  1872  (1873),  p.  625;   Vert.  Cret.  Form.  West,  1875,  p.  262. — Hay,  Bibliog.  and  Cat.  Foss. 

Vert.  N.  A.,  1902,  p.  445. 

The  type  of  this  species  is  now  a  part  of  the  Cope  collection  in  the  American  Museum  of 
Natural  History  in  New  York.  It  consists  of  a  portion  of  the  right  hyoplastron;  5  peripheral 
bones,  with  perhaps  a  fragment  of  another;  portions  of  four  costal  bones;  a  fragment  of  the 
right  hypoplastron;  and  what  Cope  regarded  as  the  head  of  the  coracoid,  but  which  seems  to 
be  rather  the  articular  end  of  the  pubis.  These  have  been  catalogged  under  the  number 
1482.  They  were  collected  from  the  upper  greensand  bed  of  the  Cretaceous,  at  Gloucester, 
New  Jersey. 

The  plastron  (plate  36,  fig.  4)  was  not  flat  below  like  that  of  the  species  of  the  other 
species  of  Agomphus,  but  very  convex.    Cope  states  that  the  curvature  from  the  peripherals 


DERMATEMYDIDiE.  25 1 

of  one  side  to  those  of  the  other  amounts  to  124°.  Unfortunately  the  free  border  of  the  front 
lobe  has  not  been  preserved,  so  that  it  is  impossible  to  determine  the  width  of  the  lobe  at  the 
base;  but  it  could  not  have  been  far  from  100  mm.  The  notch  for  the  entoplastron  shows  that 
this  bone  had  a  width  of  42  mm.  It  appears  to  have  been  broadly  rounded  behind.  While 
the  thickness  at  the  hinder  border  was  about  17  mm.,  it  was  much  thinner  at  the  front.  The 
thickness  of  the  hyoplastron  a  short  distance  behind  the  entoplastron  is  20  mm.;  at  the  hinder 
border  of  the  hyoplastron  in  the  midline,  15  mm.;  at  the  articulation  with  the  fifth  peripheral 
10  mm.     The  bone  is  therefore  very  thick  and  its  tissue  is  dense  and  heavy. 

There  is  present  a  fragment  of  the  free  border  of  the  hypoplastron,  including  a  portion  of 
the  sutural  border  for  the  xiphiplastron.  At  a  distance  of  28  mm.  from  the  free  border  the  bone 
is  18  mm.  thick.  This  continues  to  within  about  20  mm.  of  the  border,  and  then  the  bone  is 
rapidly  beveled  off  to  a  blunt  edge.  The  lower  surface  of  the  bone  curves  upward  to  meet  the 
bevel. 

The  surface  of  the  hyoplastron  and  of  the  fragment  of  the  hypoplastron  is  very  smooth, 
having  apparently  been  polisht  during  the  life  of  the  animal.  The  proximal  end  of  the  first 
costal  is  preserved.  Its  neural  border  is  concave  for  the  first  neural.  Its  hinder  angle  joined 
the  second  neural.  Here  the  bone  is  12  mm.  thick.  In  front  it  is  8  mm.  thick.  On  the  under 
side  are  seen  the  base  of  the  rib-head  and  articulation  for  the  first  rib. 

Two  adjacent  costals  of  the  right  side  (plate  37,  fig.  7),  the  fourth  and  the  fifth,  or  the 
fifth  and  the  sixth,  are  present.  They  are  each  45  mm.  in  width  at  the  proximal  end.  At  the 
suture  with  the  neurals  they  are  16  mm.  thick;  at  a  distance  of  60  mm.  from  the  neurals  one 
has  still  a  thickness  of  9  mm.  The  capitula  of  the  ribs  are  moderately  developt.  Little  or  no 
trace  is  left  of  the  rib  on  the  inner  side  of  the  costal  plates.  These  costals  are  considerably 
archt,  showing  that,  with  the  curvature  of  the  plastron,  the  shell  was  high  and  vaulted. 

Figs.   311-313. — Agomphus    petrosus. 
Peripherals  of  type.     Xj. 

311.  Section  at  anterior  end  of  second  peripheral. 

312.  Section  at  anterior  end  of  supposed   eighth 

peripheral. 

313.  Section  across  supposed  first  peripheral  of 

left  side. 

Two  anterior  peripherals  (plate  36,  fig.  4),  the  second  and  the  third  of  the  right  side,  are 
connected  with  the  outer  anterior  angle  of  the  hyoplastron.  They  are  thick  and  massive. 
The  free  edge  ot  these  peripherals  is  rounded  like  the  edge  of  one's  hand,  and  at  the  anterior 
end  of  the  second  the  border  is  slightly  everted.  Fig.  311  represents  a  section  taken  at  this 
point.  The  thickness  here  is  15  mm.  The  second  peripheral  is  40  mm.  in  length  along  the 
free  border  and  40  mm.  high.  The  third  is  50  mm.  long.  The  hinder  border  of  the  latter 
peripheral  and  the  anterior  lateral  process  of  the  hyoplastron  furnish  the  articular  border  for 
the  fourth  peripheral;  while  behind  this  is  a  part  of  the  articular  border  for  the  fifth  periph- 
eral. Two  of  the  hinder  peripherals  (plate  37,  fig.  6),  supposed  by  Cope  to  have  been  the 
eighth  and  the  ninth,  are  at  hand.  The  supposed  eighth  did  not  articulate  with  the  hypoplas- 
tron as  it  appears  to  have  done  in  Wieland's  A.  tardus  and  may  therefore  be  the  ninth.  The 
fragment  of  costal  attacht  to  it  appears  to  be  the  fifth,  since  on  it  there  is  no  trace  of  a  descend- 
ing sulcus.  These,  with  the  distal  end  of  the  fifth  costal,  are  figured  on  plate  37.  Fig.  312 
presents  a  section  across  the  anterior  end  of  the  supposed  eighth.  The  free  borders  of  these 
peripherals  are  thick  and  rounded  like  those  of  the  anterior  peripherals.  The  greatest  thickness 
of  the  eighth  is  20  mm.;  but  where  the  bone  articulates  with  the  costal  the  thickness  is  reduced 
to  6  mm.  The  ninth  peripheral  has  the  border  considerably  flared  upward  and  more  acute  than 
further  forward.  Accompanying  the  type  is  another  peripheral  (fig.  313)  which  Cope  has 
labeled  as  the  first  of  the  left  side.  On  one  side  there  is  an  excavation,  as  if  for  the  nuchal. 
However,  there  are  difficulties  in  regarding  it  as  the  first  peripheral  of  this  species  One  of 
these  is  the  great  thickness  of  the  bone  where  it  would  come  in  contact  with  the  second  periph- 
eral, being  19  mm.,  whereas  the  corresponding  border  of  the  second  peripheral  of  the  right 
side  is  only  16  mm.  thick.    Again,  as  the  upper  surface  approaches  the  free  border,  it  curves 


252 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


downward;   whereas,  the  border  of  the  second  peripheral  is  turned  upward.     It  is  probable 
that  the  bone  is  an  intrusion  from  another  species. 

The  sulci  of  the  plastron  are  wholly  effaced.  On  the  costals  they  are  narrow,  but  distinct. 
As  seen  from  plate  37,  fig.  7,  the  sulci  limiting  the  vertebral  scutes  laterally  are  not  far  removed 
from  the  costo-neural  sutures.  The  first  vertebral  was  evidently  wider  than  those  succeeding 
it.  If  the  neurals  had  the  relative  width  that  they  have  in  Adocus  punctntiis,  the  third  vertebral 
must  have  been  52  mm.  wide.  On  the  second  and  third  peripherals  the  longitudinal  sulci 
lie  not  far  above  the  free  border  of  the  carapace.  The  sulci  on  the  supposed  eighth  and  ninth 
peripherals  are  so  obscure  that  they  can  not  be  traced. 

Agomphus  tardus  Wieland. 

Test-figs.  314-318. 

Agomphus  ttii  Jus,  Wielaud,  Amer.  Jour.  Sci.  (4),  xx,  1905,  p.  430,  figs.  1-7. 

This  species  was  found  in  the  Cretaceous  marl  pits  at  Birmingham,  Burlington  County, 
New  Jersey,  in  1869.  The  type  forms  number  774  of  the  Marsh  collection  at  Yale  University. 
The  parts  recovered  are  most  of  the  nuchal,  the  second  and  the  fifth  neurals,  the  first  and 
second  left  costals;  fragments  of  the  third  and  fifth,  and  the  whole  of  the  eighth  right  costals; 
of  the  right  peripherals,  the  first,  eighth,  ninth,  and  tenth;  of  the  left  side  the  fifth,  sixth,  tenth, 
and  the  eleventh;  the  left  hyoplastron,  and  the  right  hypoplastron.    These  parts  have  enabled 


314- 


pern 


xiph     315. 


Figs.  314  and  315. — Agomphus  tardus.     Carapace  of  type. 


3'4 


Sections  at  anterior  ends  of  peripherals  indicated  by  the  numerals.     Xg.     c,  in  first  peripheral,  pit  for  pro- 
cess of  nuchal,     s,  in  eighth  peripheral,  sutural  border  for  union  with  hypoplastron;    /Jy,  section  of  pygal. 
315.  Shell  seen  from  left  side.    X0.23  c.  p.  i,  etc.,  costal  plates;  epi,  epiplastron;  Ayo,  hyoplastron;  hypo,  hypo- 
plastron;  nu./>,  nuchal  plate;  ^fr.  i,  ^er.  2,  etc.,  peripheral  bones;   at/^A,  liphiplastron. 

Dr.  Wieland  to  restore  satisfactorily  the  form  of  the  shell.  A  number  of  his  figures  are  here 
reproduced. 

The  bones  of  this  species  were  even  thicker  and  heavier  than  in  A .  petrosus.  The  shell 
(figs.  314-318)  was  elongated  and  rather  high.  Prom  the  highest  point  the  carapace  sloped 
gently  to  the  front,  while  the  rear  sloped  rapidly  downward.  The  length  of  the  carapace  was 
about  330  mm.;  the  greatest  breadth,  about  230  mm.  The  nuchal  bone  is  53  mm.  long  and 
52  mm.  wide  along  the  free  margin.  It  is  13  mm.  thick  near  the  free  margin  and  7  mm.  thick 
posteriorly.  The  second  neural  has  a  length  of  40  mm.,  an  extreme  width  of  35  mm.,  and  a 
thickness  of  14  mm.  The  fifth  neural  is  40  mm.  long,  36  mm.  wide,  and  15  mm.  thick.  As 
in  A .  petrosus,  the  first  costal  attains  considerable  thickness  at  the  junction  with  the  second 
and  third  peripherals,  being  here  22  mm.  thick.  The  rib-heads  are  diminutive.  All  the 
peripherals  are  very  obtuse  at  their  free  borders.  Fig.  314  shows  the  form  of  the  anterior  end 
of  the  first,  the  second,  the  eighth,  the  ninth,  the  tenth,  and  the  eleventh  peripherals,  as  well 
as  of  the  border  of  the  pygal  that  joins  the  eleventh  peripheral.  It  will  be  observed  that  the 
thickness  of  the  first  and  the  second  near  the  middle  of  the  height  is  maintained  to  the  costal 
border. 

The  nuchal  scute  is  moderately  broad.  The  sulci  bounding  the  vertebrals  and  the  costals 
have  not  been  observed.  The  costo-marginal  sulci  run  along  on  the  upper  half  of  the  periph- 
erals, without  at  any  time  reaching  the  costal  bones. 


dermatemydiDjS:. 


253 


The  entoplastron  is  not  present,  but  the  notch  in  the  front  of  the  hyoplastron  shows  that 
the  entoplastron  was  broadest  behind.  Its  width  was  about  45  mm.  The  hyoplastron  (fig. 
318)  is  60  mm.  long  on  the  midline  and  about  lOO  mm.  wide.  Its  greatest  thickness,  at  the 
midline,  is  27  mm.     Laterally  it  thins  to  about  9  mm.     The  hypoplastron  is  62  mm.  long  on 

the  midline,  95  mm.  wide,  and  31 
mm.  thick.  The  bridge  was  about 
106  mm.  wide. 

No  sulcus  has  been  observed 
crossingthe  front  of  the  hyoplastron 
and  the  entoplastron.  The  pectoro- 
abdominal  crosses  in  front  of  the 
hyohypoplastral  suture,  as  in  A. 
petrosus.  The  abdomino-femoral 
sulcus  swings  well  forward  on  the 
hypoplastrals.  So  far  as  observed, 
there  is  only  an  axillary  inframar- 
ginal  and  behind  it  a  single  addi- 
tional scute.  It  seems  probable 
that  the  latter  will  be  found  to 
have  been  subdivided. 


perl 


xiph 


Fig.  316. — Agomphus  tardus.  Shell  of  type,  seen 
from  right  side.  X0.23.  Lettering  with  same 
signification  as  in  Fig.  315. 


This  species  appears  to  differ  from  A.  petrosus,  its  closest  ally,  in  the  following  respects: 
The  marginal  scutes  extend  higher  on  the  peripheral  bones;  the  second  peripheral  is  relatively 
higher;  this  peripheral  of  A.  tardus  is  not  so  thick  near  the  free  border,  but  thicker  at  the  upper 

317-  318. 
.^per.l 
yper.2 

per.  Z-'-f. 


per.  6 


Figs.  317  AND  318. — Agomphus  tardus.     Shell  of  type.      X0.23. 

317.  Carapace,  seen  from  above,    c.p.i,  c./).8,  costal   plates;    n.  i,  «.8,  neural   bones;    nu.  p,  nuchal   bone; 

pfr.  I, /ler,  II,  peripheral  bones;   py,  pygal;   s/))',  suprapygal. 

318.  Shell,  seen  from  below,     ab,   abdominal   scute;    an,  anal   scute;    epi,  epiplastron;    ent,  entoplastron;    fem, 

femoral  scute;   Ajo,  hyoplastron;  Av/'o,  hypoplastron;   /)ff,  pectoral  scute;  /)fr.  2, /ifr.  6, />(?r.  1 1,  peripheral 
bones;  j:(/)A,  liphiplastron. 

border  than  in  A.  petrosus;  the  third  peripheral  is  not  so  long  (38  mm.)  as  it  is  in  A.  petrosus  (45 
mm.);  the  upper,  or  costal,  borders  of  A.  tardus  are  thicker  and  the  outer  end  of  the  hyo- 
plastron has  not  so  strong  an  upward  curve  as  in  A.  petrosus. 

From  A.  turgidus  this  species  differs  in  having  the  peripherals  nearly  as  thick  at  their 
costal  borders  as  the  maximum  thickness. 


254 


rOSSII.    TURTLES    OF    NORTH    AMERICA. 


& 


Agomphus  pectoralis  (Cope). 
Plate  37,  figs.  8,  9. 

Pleurosternum  pectorale.  Cope,  Proc.  Acad.  Nat.  Sci.  Phila.  1 868,  p.  236;  Cook'.s  Geol.  New  Jersey,  App. 

B,  1868  (1869),  p.  734;    Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1869,  p.  130. 
Adocus  pectoralis.  Cope,  Batrach.,  Reptilia,  Aves  N.  A.,  1869  (1870),  pp.  ii,  233,  plate  vii,  fig.  i;   Proc. 

Amer.  Philos.  Soc,  xi,  1870,  pp.  296,  548;    Proc.  Amer.  Philos.  Soc,  xii,  1871,  p.  43;  Vert.  Cret. 

Form.  West,  1875,  p.  262. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  444. 

The  first  mention  of  this  species,  under  the  name  Pleurosternum  pectorale,  occurs  in  the 
Proceedings  of  the  Academy  of  Natural  Science,  Philadelphia,  1868,  page  236,  in  the  de- 
scription of  Agomphus  petrosus.  This  mention  may  be  regarded  as  sufficient  to  fix  the  date 
of  the  species,  altho  the  description  is  very  brief  and  only  incidental.  Under  the  same  name  a 
full  description  and  a  figure  were  publisht  in  1869,  in  the  author's  work.  Synopsis  of  the 
Extinct  Batrachia,  Reptilia  and  Aves  of  North  America.  In  a  part  of  the  same  paper  issued  in 
1870,  the  species  was  assigned  to  the  genus  Adocus.  To  the  present  writer  the  species  appears 
to  belong  to  Agomphus. 

Agomphus  pectoralis  is  up  to  the  present  time  known  to  us  by  only  the  type  specimen, 
which  consists  of  both  hyoplastral  bones  (plate  37,  figs.  8,  9).  These  are  now  in  the  Cope 
collection,  in  the  American  Museum  of  Natural  History,  in  New  York,  and  they  have  the 
catalog  number  1478.  The  specimen  was  found  in  the  upper  bed  of  the  Cretaceous  green- 
sand,  near  Medford,  New  Jersey.  These  hyoplastrals  are  complete,  extending  from  the 
sutures  for  the  bridge  peripherals  of  one  side  to  those  of  the  other.  The  width  from  side  to 
side  is  146  mm.  The  free  borders  of  the  anterior  lobe  pass  by  a  broad  curve  into  the  axillary 
notch,  making  it  difficult  to  determine  accurately  the  width  of  the  front  lobe  at  the  base.  It 
may  be  regarded  as  about  85  mm. 

The  free  borders  of  the  epiplastrals  are  subacute,  and  from  them  the  bone  thickens 
gradually  to  the  median  longitudinal  suture.  At  the  hinder  angle  of  the  entoplastron  the 
thickness  is  15  mm.;  at  the  hinder  border  of  the  hyoplastrals,  in  the  midline,  the  thickness  is 
20  mm.    Where  these  bones  have  joined  the  peripherals  of  the  bridge,  they  are  only8  mm.  thick. 

The  hyoplastrals  are  deeply  notcht  for  the  reception  of  the  entoplastron.  This  is  pro- 
longed further  backward  than  in  the  other  species  of  the  genus.  The  axillary  notches,  too,  are 
very  deep  and  narrow.  Outside  of  each  notch  the  hyoplastron  sends  upward  and  forward  a 
strong  process,  or  buttress,  against  the  carapace.     Inwardly  this  forms  a  sharp  crest. 

The  dermal  scutes  of  this  species  differ  considerably  from  those  of  the  species  of  Adocus. 
Professor  Cope  thought  that  there  had  been  a  fusion  of  the  humeral  and  the  pectoral  scutes, 
and  that  the  sulcus  seen  crossing  the  extreme  anterior  end  of  the  left  hyoplastron  was  the 
posterior  boundary  of  the  gular  scute.  It  seems  more  probable,  however,  that  this  sulcus 
represents  the  posterior  limit  of  the  humeral.  This  interpretation  throws  the  humero-pectoral 
sulcus  indeed  far  forward,  but  it  is  little  more  so  than  it  is  in  Dermatemys  mawii  (Boulenger, 
Cat.  Chelonians,  p.  28,  fig.  8).  On  the  outer  ends  of  the  hyoplastrals  there  are  represented 
three  inframarginals.  The  axillary  is  small  and,  outside  of  the  notch,  extends  well  forward. 
The  second  inframarginal  is  hexagonal  and  represents  the  hinder  end  of  the  axillary  oi  Adocus 
punctatus.  The  third  inframarginal  rested  principally  on  the  hypoplastron.  In  Alamosemys 
suhstricta  the  arrangement  is  somewhat  as  in  the  species  here  described.  The  whole  arrange- 
ment of  the  scutes  resembles  closely  that  oi  Dermatemys  mawii,  and  there  is  little  in  the  species 
as  known  to  exclude  it  from  that  genus.  The  species  is  here  referred  to  the  genus  Agomphus 
because  of  its  close  resemblance  to  A.  turgidus.      Only  specific  differences  are  observable. 

Agomphus  firmus  (Leidy). 

Emys  firmus,hEiDY,  Proc.  Acad.  Nat.  Sci.  Phila.  1856,  p.  303;  Smithson.  Contrib.  to  Knowl.,  xiv,  1865, 

p.  106,  plate  xix,  figs.  2,  3. — Cope,  Ext.  Batrach.,  Reptilia,  Aves  N.  A.,   1869,  pp.   126,   127. — 

Maack,  Palasontographica,  xviii,  1869,  p.  277. 
Adocus  firmus,  CoPE,  Proc.  Acad.  Nat.  Sci.  Phila.  1868,  p.  235;  Cook's  Geol.  New  Jersey,  1868  (1869), 

p.  734;   Proc.  Amer.  Philos.  Soc,  xi,  1870,  p.  295. 
Agomphus  firmus.  Cope,  Proc.  Amer.  Philos.  Soc,  xii,  1871,  p.  46;   Vert.  Cret.  Form.  West.  1875,  p. 

262.— Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  445.— Wieland,  Amer.  Jour.  Sci.  (4), 

XX,  1905,  p.  4+3- 


DERMATEMYDID^. 


255 


The  materials  possest  by  Leidy  when  he  described  this  species  consisted  of  the  third, 
sixth,  and  the  seventh  left  peripherals,  the  sixth,  seventh,  and  eighth  peripherals  of  the  right 
side,  a  portion  of  the  left  hyoplastron,  and  a  portion  of  the  right  hypoplastron.  These  had 
been  placed  in  Dr.  Leidy's  hands  by  Professor  George  H.  Cook,  of  the  New  Jersey  Geological 
Survey.  They  had  been  found  in  the  uppermost  Cretaceous  greensand,  at  Tinton  Falls, 
Monmouth  County,  New  Jersey.  The  sixth  and  seventh  left  peripherals  and  the  parts  of  the 
plastron  were  figured  by  Leidy,  as  cited  above,  and  these  are  now  in  the  State  collection 
at  Rutgers  College,  New  Brunswick,  New  Jersey.  The  peripherals  mentioned  by  Leidy  are 
not  in  this  collection  at  present. 

For  figures  of  the  scanty  remains  forming  the  type  the  reader  is  referred  to  Leidy's  paper 
in  the  Smithsonian  Contributions  cited  in  the  synonymy. 

The  length  of  the  figured  peripherals  is  140  mm.  The  height  of  the  seventh  is  93  mm. 
The  costo-marginal  sulcus  crosses  these  peripherals  between  the  upper  and  middle  thirds. 
This  shows  that  the  species  does  not  belong  to  Adocus. 

The  left  hyoplastron  has  a  length  of  80  mm.,  altho  its  length  along  the  median  suture  is 
somewhat  less.  The  hypoplastron  had  a  length  of  85  mm.  but  only  65  mm.  at  the  midline. 
As  shown  by  Leidy's  figure,  the  hypoplastron  articulated  both  in  front  and  behind  with  the 
bones  of  the  opposite  side,  a  condition  not  unusual  with  the  members  of  the  family.  The 
thickness  of  the  hyoplastron  at  the  midline  and  just  behind  the  entoplastron  is  26  mm.  The 
greatest  thickness  of  the  hypoplastron  is  19  mm. 

The  excavation  in  the  front  of  the  hyoplastron  shows  that  the  entoplastron  was  truncated 
behind  and  that  its  width  was  about  65  mm.  The  pectoro-abdominal  sulcus  crost  the  hyo- 
plastron somewhat  in  front  of  the  middle  of  its  length;  while  the  abdomino-femoral  crost 
the  hypoplastron  about  the  middle  of  its  length. 

This  species,  known  up  to  the  present  time  from  only  the  type  specimens,  differs  from  all 
the  other  described  species  of  Agomphus  in  having  the  entoplastron  truncated  behind  and  in 
having  the  pectoro-abdominal  sulcus  cross  nearer  the  entoplastron  than  to  the  hinder  border 
of  the  hyoplastron. 

Agomphus  masculinus  Wieland. 
Fig.  319. 

Agomphus  masculinus ,  Wieland,  Amer.  Jour.  Sci.  (4),  xx,  1905,  p.  457,  fig.  8. 

The  type  of  this  species  belongs  to  the  Marsh  collection  at  Yale  University  Museum  and  is 
numbered  671.    It  consists  of  the  complete  plastron  and  some  portions  of  the  carapace,  includ- 
ing some  of  the  hinder  peripherals.     It  was  collected 
in  the  Upper  Cretaceous  marl  bed  at  Barnesboro, 
Gloucester  County,  New  Jersey,  in  1872. 

The  plastron  (fig.  319)  resembles  closely  that  of 
A.  turgidus,  so  far  as  the  latter  is  represented.  Dr. 
Wieland  has  mentioned  one  character  which  differ- 
entiates the  carapace  from  that  of  Cope's  species  just 
mentioned.  In  A.  masculinus  the  eleventh  and 
twelfth  marginal  scutes  overlap  the  lower  ends  of 
the  eighth  costal  bone  and  the  suprapygal;  whereas 
in  A.  turgidus  these  marginals  do  not  rise  above 
the  peripherals.  This  appears  to  be  a  sufficient 
specific  distinction. 

The  length  of  the   plastron    is    170   mm.;   the 
extreme  width,  130  mm.    The  anterior  lobe  narrows 
rapidly  from  the  base  to  the  blunt  tip.    The  width 
of  the  base  of  the  lobe  is  about  92  mm.;  the  length, 
41  mm.     The  epiplastrals  are  narrow.    The  ento- 
plastron  is  subrhombic,  33  mm.  long  and  36  mm. 
Fig.  2ig.— Agomphus  masculinus.    Plastron     wide.     Its  thickness  is  15  mm.    The  other  plastral 
of  type.     xL     Redrawn  from  Wieland's     bones  are  unsymmetrical,  as  is  common  among  the 
figure.  older  turtles.     The  left  hyoplastron  joins  the  right 


256 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


hypoplastron  a  distance  of  14  mm.;  while  the  right  hypoplastron  comes  into  contact  with  the 
left  xiphiplastron.  The  greatest  thickness  of  the  hyoplastron  and  hypoplastron  is  18  mm. 
The  distance  between  the  entoplastron  and  the  xiphiplastron  is  84  mm.  Half  of  this  may  be 
regarded  as  belonging  to  the  hyoplastrals;  the  other  half  to  the  hypoplastron. 

The  bridge  is  100  mm.  wide.  The  hinder  lobe  is  much  reduced.  The  width  at  the  base 
is  about  68  mm.;   its  length,  48  mm.     The  greatest  thickness  of  the  xiphiplastra  is  16  mm. 

The  plastral  scutes  are  well  exhibited.  Leaving  out  of  count  the  inframarginals,  there 
are  5  pairs  of  plastral  scutes,  instead  of  the  7  that  we  find  in  Adocus.  One  pair  occupies  the 
area  covered  in  Adocus  by  the  intergulars,  the  gulars,  and  the  humerals.  This  pair  joins  along 
the  midline  a  distance  of  23  mm.  The  members  of  the  pair  differ  somewhat  in  size  and  form. 
Behind  this  pair  the  median  sulcus  is  erratic  in  its  course.  The  pectorals  measure  48  mm. 
along  the  midline;  the  abdominals,  31  mm.;  the  femorals,  38  mm.;  the  anals,  28  mm.  Here, 
as  in  A.  tardus,  there  appear  to  be  only  two  inframarginals  on  each  bridge,  a  small  axillary 
scute  and  a  very  large  scute  behind  this,  reaching  to  the  inguinal  notch.  Some  of  the  marginal 
scutes  descend  on  the  outer  ends  of  the  plastral  bones. 

As  stated,  the  eleventh  and  twelfth  marginal  scutes  rise  above  the  superior  borders  of  the 
peripherals  supporting  them.    In  front  of  them  the  marginals  are  confined  to  the  peripherals. 

Agomphus  oxysternum  (Cope). 
Fig.  320. 

Amphitmys  oxysternum,  CoPE,  Proc.  Amer.  Philos.  Soc.  XVII,  1877,  p.  82;   Palaeontolog.  Bull.  No.  25, 

1877,  p.  2;   Amer.  Naturalist,  xii,  1878,  p.  129. 
Agomphus  oxysternum.  Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  445. — Wieland,  Amer.  Jour. 

Sci.  (4),  XX,  1905,  p.  443. 

The  type  of  the  present  species  is  in  the  collection  of  the  Geological  Survey  of  Georgia,  at 
Atlanta,  where  the  writer  has  been  permitted  to  study  it.  The  specimen  was  found  near  Monte- 
zuma, Macon  County,  near  the  Flint  River,  in  what  is  known 
as  the  Midway  formation,  a  member  of  the  Lower  Eocene.  It 
is  in  the  same  condition  as  when  it  was  described  by  Professor 
Cope,  the  plastron  being  present,  as  well  as  the  anterior  portion 
of  the  carapace  and  the  left  border  as  far  as  the  hinder  end  of  the 
eighth  peripheral.  The  core  of  matrix  which  filled  the  shell  is  in 
large  part  present  and  on  it  are  indicated  the  sutures  between  the 
series  of  neural  and  costal  bones.  In  form  the  shell  appears  to 
have  been  similar  to  that  oi  A.  tardus. 

The  length  of  the  carapace,  from  the  front  of  the  nuchal  to  the 
hinder  border  of  the  seventh  costal,  is  242  mm.  Cope  gives  this  as 
250  mm.  The  width  is  184  mm.;  the  height,  150  mm.  or  a  little 
more. 

The  free  border  in  front  of  the  bridge  is  thick,  obtuse,  and 
slightly  flared  upward.  The  hinder  end  of  the  eighth  peripheral 
is  18  mm.  thick,  and  the  free  border  is  very  obtuse.  The  nuchal 
bone  measures  about  50  mm.  along  the  free  border,  75  mm. 
where  widest,  and  41  mm.  from  front  to  the  rear.  The  neurals, 
except  the  first,  are  slightly  wider  than  long.  The  dimensions  of 
three  of  them  are  given  in  the  table  on  the  following  page. 

The  neurals  and  costals  are  thick.  Cope  states  that  the 
second  neural  is  13  mm.  thick;  the  second  costal,  12  mm.  The 
latter  bone  near  the  neural  is  only  10  mm.  thick.  The  first  per- 
ipheral measures  along  the  free  border  38  mm.;  the  third,  40 
mm.    The  first  is  33  mm.  high;  the  second,  38  mm. 

The  first  vertebral  scute  is  53  mm.  long  and  52  mm.  wide. 
Its  lateral  borders  are  nearly  parallel.  The  second  vertebral  is  70  mm.  wide.  The  marginal 
scutes,  as  far  backward  as  the  middle  of  the  bridge,  run  about  40  mm.  below  the  costo-periph- 
eral  sutures. 


Fig.  320. — Agomphus  oxyster- 
num.    Carapace    of    type. 


Neural. 

Length . 

Width. 

I 
% 
5 

38 

3' 
3' 

27 
33 
32 

DERMATEMYDID.S:.  257 

The  plastron  has  the  extremities  of  the  front  and  hinder  lobes  slightly  elevated  above  the 
portion  between  the  bridges.  The  length  is  211  mm.  The  anterior  lobe  is  broadly  rounded  in 
front;  the  posterior  is  short  and  pointed  behind.    The  width  of  the  anterior,  on  a  line  crossing 

at  the  hinder  border  of  the  entoplastron,  is  102  mm.;  its  length 
is  57  mm.  The  entoplastron  is  pointed  in  front,  rounded  behind, 
42  mm.  long  and  46  mm.  wide.  The  bridge  has  a  width  of  94 
mm.  The  hinder  lobe  has  a  width,  taken  from  the  ends  of  the 
abdomino-femoral  sulci,  of  88  mm.    Its  length  is  57  mm. 

Some  of  the  sulci  of  the  plastron  are  very  obscure.  Cope 
was  in  doubt  regarding  some  of  those  on  the  anterior  lobe.  One 
sulcus  crosses  the  entoplastron  37  mm.  behind  the  front  of 
the  lobe.  Cope  regarded  this  as  the  gulo-humeral;  the  writer  regards  it  as  the  humero-pectoral. 
The  area  in  front  of  this  appears  to  the  writer  to  be  divided  on  each  side  into  an  intergular, 
whose  extent  backward  is  doubtful,  a  small  triangular  gular,  and  a  large  humeral.  Cope 
appears  to  have  been  doubtful  whether  the  sulcus  behind  the  scutes,  called  by  the  present 
writer  gulars,  continued  directly  across  the  front  lobe,  cutting  off  intergulars  in  front,  or 
turned  backward  and  reacht  the  sulcus  which  crosses  the  entoplastron. 

Cope  found  evidences  of  a  sulcus,  his  humero-pectoral,  which  commenct  near  the  axillary 
notch,  ran  forward  parallel  with  the  free  border  of  the  lobe,  then  turned  inward  and  somewhat 
backward,  to  cross  the  midline  a  little  behind  the  entoplastron.  The  present  writer,  examining 
the  plastron  without  knowing  Cope's  determinations,  did  not  observe  such  a  sulcus.  It  is 
not  found  on  other  species  oS.  Agomphus. 

According  to  the  writer's  determinations,  the  pectoral  scutes  join  along  the  midline  a 
distance  of  58  mm.;  the  abdominals,  a  distance  of  26  mm.  The  femoro-anal  sulcus  appears  to 
be  where  drawn.  Cope  concluded  that  inframarginal  scutes  are  present.  The  writer  has  no 
doubt  regarding  this. 

Dr.  George  Baur  (Zool.  Anzeiger,  xi,  1888,  p.  595)  stated  that  he  had  examined  the 
type  of  this  species  and  regarded  it  as  belonging  to  the  genus  Agomphus.  He  also  informed  us 
that  additional  materials  existed  in  the  Yale  University  collection,  but  nothing  further  has 
been  heard  of  them. 

Genus  ZYGORAMMA  Cope. 

Characters,  so  far  as  known,  those  of  Adocus,  except  that  the  hypoplastron  sends  no 
buttress  to  the  costals,  but  each  sends  a  process  into  a  pit  between  the  seventh  and  eighth 
peripherals.  Bones  of  the  carapace  and  plastron  comparatively  thin.  Costals  articulating 
with  peripherals  by  suture  and  gomphosis.  Rib-heads  feebly  developt,  except  on  the  first 
costals.  Surface  of  carapace  striated.  Posterior  marginal  scutes  rising  on  the  costal  bones 
as  in  Adocus. 

Type:    Zygoramma  striatula  Cope. 

Zygoramma  striatula  Cope. 
Plate  37,  fig.  10;    plate  38,  figs.  1-3;   text-fig.  321. 

Zygoramma  striatula.  Cope,  Proc.  Atner.  Philos.  Soc,  xi,   1870,  p.  550;   Ibid,  xii,  1871,  p.  44;  Vert. 
Cret.  Form.  West,  1875,  p.  263. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  445. 

This  species  was  based  on  rather  fragmentary  materials  which  were  collected  from  the 
upper  greensand  bed  of  the  Cretaceous,  at  Pemberton,  Burlington  County,  New  Jersey. 
The  remains  consist  of  the  greater  portion  of  both  hypoplastra,  5  posterior  peripherals,  and 
fragments  of  3  costal  bones.  This  type  is  in  the  American  Museum  of  Natural  History  and 
bears  the  catalog  number  2358. 

The  hypoplastrals  (plate  38,  fig.  i)  are  thin,  the  thickness  everywhere  along  the  hyo- 
hypoplastral  suture  present  being  only  6  mm.  Near  the  midline,  just  in  front  of  the  suture 
with  the  xiphiplastrals,  the  thickness  is  7  mm.,  increasing  to  9  mm.  near  the  free  border, 
behind  the  inguinal  notch. 

The  sutures  are  coarse,  each  bone  sending  large  teeth  into  pits  of  the  other.  These  pits 
and  teeth  belong  to  the  deeper  layers  of  the  bone;   while  the  sutures,  as  seen  from  below, 

17 


258  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

form  nearly  smooth  lines.  The  hypoplastra  meet  along  the  midline  a  distance  of  80  mm.  The 
one  of  the  right  side  has  articulated  by  its  anterior  angle  with  the  left  hyoplastron  for  a  short 
distance.  The  free  border  of  the  left  hypoplastron  is  present  from  the  inguinal  notch  to 
xiphiplastral  suture.  Below,  it  presents  an  acute  edge;  but  the  bone  thickens  rapidly.  Out- 
side of  the  notch  a  process  is  sent  outward  and  upward  to  enter  a  pit  between  the  seventh 
and  eighth  peripherals.  The  abdomino-femoral  sulcus  crosses  the  hypoplastra  a  little  nearer 
the  anterior  end  of  these  bones.  The  region  where  we  might  expect  to  find  the  inframarginal 
scutes  is  broken  away.    The  longitudinal  median  sulcus  is  not  seen. 

The  sculpture  of  the  plastron  is  obscure,  but  there  are  evidences  everywhere  of  shallow  pits, 
and  these  were  arranged,  at  least  partly,  in  rows. 

There  are  preserved  the  distal  ends  of  2  costals,  one  of  which  is  the  sixth  of  the  right  side, 
while  the  other  belongs  to  the  left  side.  The  sixth  of  the  right  side  (plate  38,  fig.  2)  is  38  mm. 
wide  and  4  mm.  thick.  It  is  attacht  principally  to  the  eighth  peripheral,  but  also  to  the  anterior 
angle  of  the  ninth.  On  the  outer  surface  are  seen  parts  of  the  third  and  fourth  costal  scutes, 
and  of  the  eighth  and  ninth  marginal  scutes.  The  other  distal  end  of  a  costal,  probably  the 
fifth  of  the  left  side,  is  43  mm.  wide  and  4  mm.  thick.  A  fragment  of  a  costal  from  about  the 
middle  of  the  length  of  the  bone  is  35  mm.  wide  and  6  mm.  thick.  This  seems  to  indicate 
that  the  costals  thickened  considerably  toward  the  neurals. 

Three  successive  peripherals  of  the  right  side  are  among  the  materials,  the  seventh, 
eighth,  and  ninth  (plate  38,  fig.  2).  They  are  remarkable  for  their  great  height.  The  seventh 
measures  46  mm.  along  the  free  border;  the  eighth  and  ninth,  each  49  mm.  The  height  of 
the  latter  is  65  mm.  The  exterior  surface  of  the  seventh  is  convex,  with  the  free  edge  flared 
slightly  upward.  The  other  two  are  not  curved  vertically,  but  are  convex  from  front  to  back. 
The  greatest  thickness  of  the  ninth  is  at  the  front  border,  1 1  mm.  The  thickness  is  reduced 
upward  to  the  sutural  border,  less  rapidly  downward  to  the  sharp  free  edge.  The  eighth 
thickens  rapidly  toward  the  anterior  end,  where,  at  the  middle  of  the  height,  the  thickness  is 
23  mm.  The  thickening  is  exprest  on  the  inner  surface  as  a  ridge.  The  hinder  and  lower 
inner  portion  of  the  seventh  is  likewise  thickened,  but  the  front  and  upper  part  is  excavated 
by  the  visceral  chamber.  Above  the  thickened  ridge,  on  the  inside  of  each  of  these  peripherals, 
is  seen  the  mouth  of  a  deep  pit  which  received  the  free  end  of  a  rib.  Two  of  these  rib-ends 
are  yet  in  place,  one  belonging  to  the  sixth  costal. 

Between  the  seventh  and  eighth  peripherals,  on  their  inner  side  (plate  38,  fig.  3),  there  is 
a  deep  pit,  excavated  principally  in  the  seventh,  which  has  received  the  extremity  of  the 
inguinal  process  of  the  hypoplastron.  The  latter  did  not  rise  to  the  height  of  the  costal  plates. 
From  the  front  of  the  pit  a  sharp  ridge  runs  downward  and  forward.  This  has  its  inwardly 
projecting  edge  broken  away,  but  it  quite  certainly  furnisht  an  articulation  with  the  outer 
border  of  the  hypoplastron.  The  seventh  peripheral  of  the  left  side  is  present,  but  furnishes 
no  additional  information.  A  more  posterior  peripheral,  possibly  the  eleventh,  has  the  exterior 
surface  considerably  more  concave  vertically  than  that  of  the  more  anterior  ones,  showing 

that  the  hinder  border  of  the  carapace  was  flared  upward.  Plate 
37,  fig.  ID,  shows  a  fragment  of  a  bridge  peripheral  with  a  portion 
of  the  end  of  a  rib  inserted  in  a  furrow.  Text-fig.  321  represents 
a  section  of  a  bridge  peripheral  showing  that  there  was  a  sharp 
keel  along  the  side. 

„  „  .As  will  be  observed  from  the  plate,  the  hinder  marginal  scutes 

riG.  ^21. — Lyeoramma  stria-  ,    ,  ,  ,     ,  •-ri        •     1  •      1  1  -j  i_ 

,  ,         c  ^.-  extended  up  on  the  costal  plates.     1  he  nmth  margmal  has  a  width 

tula.       Section    across    a  ire  jL-i_ro  t  uj 

bridee  peripheral.     Xs.      lore  and  att  ot  52  mm.,  and  a  height  of  85  mm.    Its  upper  border 

displays  some  of  the  irregularities  so  common  among  the  Der- 

matemydidae.     On  the  costal  supposed  to  be  the  fifth  of  the  left  side  the  sulcus  between  the 

marginal  and  the  costal  scutes  runs  lower  down. 

The  outer  surface  of  the  costals  and  peripherals  is  sculptured  into  low  ridges  and  shallow 
grooves.     These  are  mostly  directed  from  the  front  of  the  bone  backward,  but  often  also 
slightly  downward.    The  downward  inclination  is  seen  especially  on  the  more  posterior  bones. 
The  length  of  the  carapace  of  this  specimen  is  estimated  at  380  mm. 


DERMATEMYDID^. 


259 


Zygoramma  microglypha  Cope. 
Fig.  321. 

Zygoramma  microglypha.  Cope,  Proc.  Amer.  Philos.  Soc,  xii,  1871,  p.  44;  Vert.Cret.  Form.  West,  1875, 
p.  263. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  445. 

The  remains  described  under  the  above  name  were  found  at  Birmingham,  New  Jersey, 
in  the  uppermost  stratum  of  Cretaceous  greensand.  They  consisted  of  the  greater  part  of  the 
plastron  and  half  of  the  carapace,  with  4  peripheral  bones,  of  an  individual  whose  carapace 
must  have  had  a  length  of  about  600  mm.  A  portion  of  this  material  has  been  recognized  in 
the  Cope  collection  of  reptiles,  in  the  American  Museum  of  Natural  History,  and  this  bears 
the  number  6129.  Unfortunately,  up  to  the  present  time,  no  bones  of  the  plastron  have  been 
found  in  the  collection.     No  part  of  the  species  has  hitherto  been  figured. 

The  plastron  is  described  as  having  a  total  length  of  457  mm.  According  to  Cope's 
measurements,  the  length  of  the  hyoplastron  was  81  mm.;  that  of  the  hypoplastron,  145  mm.; 
that  of  the  xiphiplastron,  117  mm.    The  length  of  the  hyoplastron  was  probably  taken  along 

the  midline.  The  front  of  the  plastron 
was  truncated.  The  width  of  the 
entoplastron  was  95  mm.;  its  length 
something  less;  its  thickness  1 1. 6 mm. 
The  posterior  border  was  truncated; 
the  anterior  border,  regularly  convex. 
The  posterior  plastral  lobe  was  regu- 
larly contracted,  and  rounded,  and  it 
had  a  thin  edge.  Its  width  at  the 
hypoxiphiplastral  suture  was  220 
mm.;  the  thickness  at  the  midline, 
15.8  mm. 

The  peripheral  bones  at  the 
bridges  are  said  to  have  had  a  thick- 
ened shoulder  within,  into  which  the 
slender  costal  processes  were  received. 
The  free  peripherals  were  of  lighter 
construction  and  somewhat  everted. 
Most  of  the  bones  of  the  carapace 
that  have  been  certainly  identified  are 
here  figured  (fig.  322).  These  consist 
of  a  portion  of  the  first  neural,  the 
third  and  the  fourth  neurals,  the  prox- 
imal end  of  the  first  and  third  left  cos- 
tals,  parts  or  wholes  of  the  second, 
third,  fourth,  and  fifth  right  costals, 


Portion  of  carapace 


Fig.  322. — Zygoramma  microglypha. 
of  type.      X\. 

c.  p*  If  c.  p.  3,  c.  p.  5,  costal  plates;   n.  i,  n.  3,  n.  4,  neural  bones. 

and  portions  of  other  costals  whose  positions  can  not  be  determined. 

The  first  neural  has  a  length  of  about  57  mm.;  its  width  is  45  mm.;  its  thickness,  8  mm. 
The  third  and  the  fourth  have  each  a  median  length  of  60  mm.  and  a  maximum  width  of 
37  mm.  Each  is  excavated  in  front  for  the  preceding  neural.  Each  has  a  thickness,  where 
it  joined  the  costal,  of  10  mm.  The  first  costal  is  80  mm.  wide;  the  second,  56  mm.;  the  third 
59  mm. ;  the  fourth,  55  mm.  On  the  lower  side  of  the  first  there  is  the  base  of  a  strong  rib- 
head,  and  in  front  of  this  a  rough  articulation  for  the  first  rib.  The  rib-heads  of  the  other 
costals  are  very  feebly  developt. 

The  sulci  between  the  horny  scutes  are  moderately  distinct.  The  second  vertebral  had 
a  length  close  to  105  mm.  and  a  width  about  equal  to  the  length.  The  first  vertebral  must 
have  been  considerably  wider  than  the  second.  The  third  vertebral  appears  to  have  had  a 
length  of  115  mm.  and  a  width  close  to  95  mm. 

As  in  Z.  striatiila,  the  marginal  scutes  extend  high  up  on  the  distal  ends  of  the  costal  bones, 
as  may  be  seen  from  the  figure.    They  pursue  an  irregular  course. 


26o  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

According  to  Cope,  the  intergular  scutes  formed  a  single  shield,  which  was  large,  pentag- 
onal, with  straight  sides,  and  broader  than  long.  This  shield  separated  widely  the  gulars 
from  each  other.  The  pectorals  encroacht  on  the  entoplastron;  laterally  they  were  narrow. 
The  abdomino-femoral  sulcus  crost  the  hypoplastra  a  little  behind  their  middle.  The  median 
longitudinal  sulcus  pursued  an  erratic  course. 

This  species  evidently  resembled  closely  Z.  striatula.  The  distinguishing  character  most 
obvious  is  the  finer  and  conspicuously  punctate  sculpture.  Cope  states  that  the  costal  pro- 
cesses that  fit  into  the  peripherals  of  Z.  striatula  are  relatively  twice  as  large  as  those  of  Z. 
microglypha. 

In  its  sculpture  this  species  resembles  the  species  of  Adocus. 

Genus  HOMOROPHUS  Cope. 

A  remarkable,  but  insufficiently  known  genus  of  Dermatemydidae.  Costal  rib-heads 
wanting  or  vestigial.  Neurals,  in  the  type  and  only  known  specimen,  co-ossified  with  the  cos- 
tals.  The  superior  face  of  each  neural  much  wider  than  the  inferior  face.  Vertebral  scutes  in 
most  places  narrower  than  the  neurals. 

Type:   Homorophus  tnsuetus  Cope. 

Homorophus  insuetus  Cope 

Homorophus  insuetus,  CoPE,  Proc.  Amer.  Philos.  Soc,  XI,  1870,  p.  552;   Ibid.,  XTI,  1871,  p.  44;  Vert. 
Cret.  Form.  West,  1875,  p.  263. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  446. 

The  type  of  this  species  appears  to  be  lost.  It  was  discovered  in  the  uppermost  bed  of 
Cretaceous  greensand,  at  Pemberton,  Burlington  County,  New  Jersey.  Cope  does  not  state 
what  parts  of  the  shell  he  had,  but  he  describes  some  neural  bones,  the  entoplastron,  the 
hyoplastron,  the  hypoplastron,  and  some  costals.  He  had  neither  the  epiplastra  nor  the 
xiphiplastra. 

The  hyoplastron  and  the  hypoplastron  together  measured  200  mm.  along  the  midline. 
On  comparing  these  parts  of  the  plastron  with  the  same  parts  in  Baptemys  it  is  concluded  that 
the  plastron  had  a  length  of  about  420  mm. 

The  sutures  bounding  the  neural  bones  appear  to  have  been  obscure.  Cope  says  that  one 
of  the  neurals  was  14  mm.  thick,  60  mm.  long,  28.5  mm.  wide  in  front,  and  91  mm.  wide 
behind.  It  is  possible  that  there  was  here  some  error  in  observation  or  in  statement.  On  the 
visceral  face  the  neurals  were  very  narrow,  but  they  expanded,  so  that  a  transverse  section 
resembled  that  of  a  broad  wedge  with  truncated  apex.  The  vertebral  scutes  had  a  remarkable 
form.  For  the  most  part,  they  were  narrower  than  the  neural  bones.  One  is  described  as 
having  the  front  coffin-shaped,  the  lateral  margins  concave,  and  the  posterior  end  expanded, 
so  that  the  scute  was  fiddle-shaped.  The  anterior  vertebral  is  stated  to  have  been  60  mm. 
long  and  35  mm.  wide  anteriorly.  The  posterior  costal  scutes  are  described  as  meeting 
in  the  midline  behind. 

The  thickness  of  the  hyoplastron  was  15  mm.  The  free  border  of  the  hypoplastron  was 
thinned  to  an  edge. 

Genus  ALAMOSEMYS  nov. 

Differs  from  Adocus,  so  far  as  known,  in  having  the  marginal  scutes  wholly  excluded  from 
the  costal  bones. 

Type:    Alamosemys  subsinctaHzy. 

The  generic  name  is  derived  from  the  name  of  the  stream  where  the  type  was  found. 

Alamosemys   substricta  sp.  nov. 
Plate  39,  figs.  I,  2;   teit-figs.  323,  324. 

The  specimen  which  serves  as  the  type  of  this  species  was  collected  in  the  Torrejon 
deposits  of  New  Mexico,  near  the  head  of  Alamosa  Creek,  in  1896,  by  Dr.  J.  L.  Wortman 
and  Mr.  W.  Granger.    It  bears  the  catalog  number  1204,  in  the  American  Museum. 


DERMATEMYDIDj^. 


261 


The  specimen  is  a  complete  shell,  extremely  little  damage  having  been  done  to  either  the 
carapace  or  the  plastron  through  loss  of  any  part.  Unfortunately,  however,  an  extremely 
compact  clayey  limestone  has  envelopt  the  shell,  and  this  clings  so  closely  to  the  bone  that  it 
was  very  difficult  to  remove  it.  In  addition  to  this,  there  had  been  deposited  over  considerable 
portions  of  the  shell  scattered  nodular  masses  of  hematite,  which  became  so  thoroly 
attacht  to  the  bone  that,  in  removing  them,  the  surface  of  the  bone  was  somewhat  injured. 
This  condition  has  resulted  in  making  it  very  difficult  to  determine  the  position  and  courses 
of  some  of  the  sutures  between  the  bones,  and  likewise  the  impressions  between  the  different 
epidermal  scutes.  Many  of  the  bone  sutures  could  be  determined  only  by  removing,  by 
means  of  hydrochloric  acid,  a  thin  layer  of  bone  so  that  the  matrix  in  the  sutures  projected 
a  little.  The  obdurate  nature  of  the  matrix  which  fills  the  shell  has  seemed  to  render  it 
inadvisable  to  attempt  to  remove  it  for  the  purpose  of  seeing  characters  found  on  the  inside 
of  the  shell. 

The  specimen  has  been  carefully  studied  and  the  various  sutures  and  sulci  have  been 
represented  in  the  figures  herewith  provided.  As  to  the  bone  sutures,  they  have  been  satis- 
factorily made  out  and  may  be  relied  upon.  Many  of  the  epidermal  sulci  have  been  more 
difficult  to  determine;  but  in  general,  it  is  believed  that  they  are  correctly  mapt. 


324- 


Figs.  323  and  324. — Alamosemys  substricta.     Carapace  and  plastron  of  type.      Xj. 
323.  Carapace.  324.  Plastron. 

The  carapace  (plate  39,  fig.  i ;  text-fig.  323)  is  elongated,  moderately  elevated,  decidedly 
constricted  at  the  inguinal  notches,  and  with  the  peripherals  behind  these  somewhat  flaring. 
A  remarkable  feature  of  the  shell,  shared  by  Adocus,  is  the  large  part  of  it  which  lies  behind 
the  sutures  separating  the  third  and  fourth  costal  plates  above  and  that  which  separates  the 
hyoplastrals  from  the  hypoplastrals.  Sixty  per  cent,  of  the  length  lies  behind  the  line  indicated. 
So  far  as  known  to  the  writer,  this  is  approacht  only  in  Chelydra  of  living  genera.  Nearly 
half  of  the  entire  length  lies  behind  the  inguinal  notches. 

In  front,  over  the  neck,  there  is  an  emargination  in  the  border  of  the  shell,  while  there  are 
some  feeble  serrations  in  the  hinder  border.  The  extreme  length  of  the  carapace,  in  a  straight 
line,  is  550  mm.  The  greatest  width,  380  mm.,  is  just  behind  the  inguinal  notches;  between 
the  third  and  fourth  costals  the  width  is  372  mm.  The  greatest  depth  of  the  shell  is  150  mm., 
but  in  life  this  may  have  been  greater.  On  each  side  of  the  middle  line  of  the  carapace,  for 
some  distance,  the  shell  is  flat,  there  being  no  suggestion  of  a  keel.  The  nuchal  bone  is  55  mm. 
long  in  the  midline;  its  lateral  extent  is  53  mm.  at  the  anterior  margin;  90  mm.  where  widest. 
There  are  7  neurals.  The  eighth  was  wholly  supprest;  the  sixth  and  seventh  were  reduced  in 
size  and  crowded  forward.  The  first  is  broadly  oval,  57  mm.  long  and  32  mm.  wide.  The 
second  is  narrowly  oval,  44  mm.  long  and  18  mm.  wide;   the  third,  fourth,  and  fifth  are  hex- 


262  FOSSIL    TURTLES    OK    NORTH    AMERICA. 

agonal,  with  the  broader  end  forward;  the  third  being  56  mm.  long  and  25  mm.  wide;  the 
fourth,  46  mm.  long  and  22  mm.  wide;  the  fifth,  38  mm.  long  and  22  mm.  wide.  The  sixth  is 
hexagonal,  20  mm.  long  and  28  mm.  wide.  The  seventh  neural  is  pentagonal,  22  mm.  long  and 
17  mm.  wide.  It  has  the  appearance  of  having  been  crowded  far  forward  out  of  its  place. 
There  is  a  single  broad  suprapygal  whose  length  is  46  mm.  and  width  100  mm. 

The  members  of  the  sixth,  seventh,  and  eighth  pairs  of  costals  respectively  meet  along 
the  midline.  The  suture  between  those  of  the  eighth  pair  is  82  mm.  long.  The  peripherals 
are  unusually  high,  about  100  mm.  along  the  sides;  somewhat  less  toward  each  extremity  of 
the  animal,  the  first  and  eleventh  being  about  64  mm.  high.  The  free  peripherals  are  thin  at 
the  borders,  and  the  hinder  ones  are  reduced  to  a  sharp  edge.  The  thickness  of  the  second 
peripheral,  near  the  upper  border,  is  20  mm.;  that  of  the  ninth,  at  the  upper  border,  is  16 
mm.    There  are  1 1  of  these  peripherals  on  each  side. 

As  stated,  it  is  difficult,  in  a  few  cases  impossible,  to  determine  satisfactorily  the  bound- 
aries of  the  epidermal  scutes.  In  front  there  is  a  very  narrow  nuchal,  about  10  mm.  wide 
and  20  mm.  long.  This  is  followed  by  a  first  marginal,  58  mm.  along  the  front  edge  and 
30  mm.  fore  and  aft.  The  sulci  between  the  marginals  and  the  costal  scutes  appear  to  run  at 
a  considerable  distance  below  the  sutures  between  the  costal  and  peripheral  bones,  the  mar- 
ginals being  about  75  mm.  high.  The  limits  of  the  vertebral  scutes  are  satisfactorily  deter- 
mined, except  those  of  the  fifth.  The  first  vertebral  is  80  mm.  long  and  130  mm.  across  its 
anterior  end.  The  second  is  100  mm.  long  and  65  mm.  wide;  the  third  90  mm.  long  and  66  mm. 
wide;  the  fourth  apparently  108  mm.  long  and  close  to  58  mm.  wide.  The  fifth  was  probably 
1 15  mm.  long  and  about  130  mm.  wide. 

The  surface  of  the  carapace,  including  the  lower  faces  of  the  peripherals,  is  ornamented 
with  narrow  and  low  longitudinal  wrinkles  of  which  there  are  from  five  to  eight  in  a  10  mm. 
line.  They  are  possibly  due  to  the  great  age  of  the  specimen  and  may  be  wanting  in  the 
younger  individuals. 

The  plastron  (plate  39,  fig.  2;  text-fig.  324)  is  well  developt,  altho  it  leaves  wide  spaces 
between  it  and  the  carapace.  It  was  apparently  quite  flat,  altho  now  somewhat  concave 
transversely,  the  result  possibly  of  pressure.  The  total  length  is  415  mm.  The  anterior  lobe 
projects  nearly  as  far  forward  as  the  anterior  border  of  the  carapace;  but  the  hinder  fails  to 
extend  as  far  backward  as  the  carapace  by  about  115  mm.  The  anterior  end  of  the  plastron 
is  very  slightly  emarginated;  the  posterior  end  is  broadly  rounded  and  without  notch. 

The  length  of  the  anterior  lobe  is  100  mm.;  its  width  at  the  axillary  notch  209  mm.  It 
decreases  in  width  gradually  at  first,  then  rounds  rapidly  to  the  notch  in  front.  Its  thickness 
near  the  front  is  9  mm.  The  length  of  the  posterior  lobe  is  132  mm.;  its  width  at  the  inguinal 
notches  is  190  mm.  The  bridge  is  180  mm.  in  width.  The  axillary  and  inguinal  buttresses 
do  not  appear  to  extend  inward  beyond  the  adjacent  borders  of  the  plastron. 

The  entoplastral  bone  is  short  and  broad  and  with  a  nearly  straight  hinder  border.  Its 
length  is  55  mm;  its  width,  90  mm.  The  hyoplastral  bones  meet  along  the  midline  for  a  dis- 
tance of  100  mm.  The  suture  separating  the  hypoplastrals  from  the  xiphiplastrals  is  believed 
to  be  placed  as  shown  in  the  figures.  The  former  bones  occupy  135  mm.  of  the  midline;  the 
latter,  84  mm. 

Gular  and  intergular  scutes  seem  to  be  present  and  to  have  the  positions  and  forms  given 
them  in  the  figures.  The  intergular  area  is  evidently  divided  by  a  median  sulcus.  The  two 
taken  together  are  75  mm.  wide  and  50  mm.  long.  The  gulars  are  small,  triangular,  and 
widely  separated  by  the  intergulars. 

The  humero-pectoral  sulcus  crosses  the  midline  at  the  hinder  end  of  the  entoplastron. 
The  humerals  meet  on  the  entoplastron  for  a  distance  of  48  mm.  The  pectorals  extend 
along  the  midline  only  46  mm.  Altho  the  femoro-abdominal  sulcus  is  not  as  distinct  as 
might  be  desired,  it  is  probably  placed  correctly  in  the  figures.  The  abdominals  thus  have  a 
fore-and-aft  extent  of  128  mm.  The  femorals  extend  along  the  midline  80  mm.;  the  anals, 
67  mm. 

On  the  bridges  of  the  plastron  there  are  at  least  four  inframarginals.  Of  these,  the  one 
in  front  is  small  and  square;  the  second,  pentagonal;  while  the  fifth  is  probably  hexagonal. 
The  third  is  95  mm.  long  and  42  mm.  wide,  and  may  possibly  be  subdivided;  but  no  sulcus 
is  visible. 


DERMATEMYDID^.  263 

The  surface  of  the  bones  of  the  plastron  appears,  for  the  most  part,  to  have  been  smooth, 
but  there  are  some  indications  of  the  same  kind  of  wrinkling,  or  folding,  as  is  seen  on  the  upper 
surface.    This  is  especially  the  case  on  the  bridges  and  lower  ends  of  the  bridge  peripherals. 

Genus  HOPLOCHELYS  nov. 

Shell  thick  and  solid.  Peripherals  united  to  the  plastral  bones  by  means  of  digitations 
and  dentated  sutures;  with  the  costals  by  gomphosis  and  in  addition  by  simple  apposition  or 
sutures.  Carapace  furnisht  above  with  three  carinas.  Plastron  with  anterior  lobe  immovable 
and  with  the  posterior  lobe  narrow. 

Type:    Chelydra  crassa  Cope. 

The  characters  of  this  genus  are  derived  wholly  from  the  shell.  The  plastral  structures 
are  not  well  known  in  any  of  the  species.  The  genus  appears  to  be  related  to  Staurotypus 
now  living  in  Central  America.  The  latter  possesses  only  10  peripheral  bones  on  each  side. 
It  appears  not  improbable  that  H.  saliens  and  H.  paludosa,  having  the  peripherals  sutured 
to  the  costals,  really  belong  to  a  distinct  genus. 

Hoplochelys  crassa  (Cope). 
Plate  38,  figs.  4-9;   text-fig.  325. 

Dermatemys  sp.,  CoPE,  Proc.  Amer.  Philos.  Soc,  XX,  1882,  p.  461  (no  description). 

Chelydra  crassa,  CoPE,  Science  (i),  XI,  1888,  p.  198  (no  description);   Trans.  Amer.  Philos.  Soc,  (2,) 

XVI,  1888,  p.  306. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  446. 
Hoplochelys  crassa.  Hay,  Amer.  Geologist,  xxxv,  1905,  p.  ^39. 

Professor  Cope's  first  description  of  this  species  appeared  in  the  Transactions  of  the 
American  Philosophical  Society  as  cited  above;  but  he  had  previously  mentioned  it,  as  earl>- 
as  the  year  1882,  as  a  species  oi  Dermatemys.  In  no  place  does  this  author  state  the  exact 
locality  or  level  at  which  the  specimens  were  found  by  his  collector,  Mr.  David  Baldwin. 
However,  Cope's  label,  which  accompanies  the  type  specimen,  states  that  it  was  found  June 
6,  1883;  and  Dr.  W.  D.  Matthew  has  been  able  to  show  from  the  labels  found  with  the  mam- 
mals collected  by  Mr.  Baldwin  that  at  that  time  the  collector  was  in  the  neighborhood  of 
Chaco  Canyon,  San  Juan  County,  New  Mexico.  Both  the  Puerco  and  the  Torrejon  are 
found  in  that  region  and  it  is  therefore  uncertain  to  which  of  these  the  fossil  belongs.  Two 
other  species  referred  to  the  genus  come  from  the  Torrejon.  Cope's  first  mention  of  the 
species  in  1882  was  doubtless  based  on  other  specimens,  possibly  the  three  neurals  of  which 
he  speaks  in  his  description. 

Cope  states  that  he  possest  remains  of  2  individuals.  Of  the  first  there  were  present  2 
vertebral  bones,  9  peripherals,  and  3  plastrals;  of  the  second,  3  vertebrals.  The  bones  of  the 
first-mentioned  individual  are  now  in  the  American  Museum  of  Natural  History  and  bear  the 
catalog  number  6091;  where  the  remains  of  the  second  specimen  are  is  not  at  present  known. 

Of  the  9  peripherals  in  Professor  Cope's  possession  4  are  represented  by  only  as  many 
fragments.  No  neurals  are  present,  but  there  are  2  fragments  of  costal  plates  (plate  38,  fig.  8), 
which  are  not  mentioned  by  Cope;  unless,  indeed,  they  were  mistaken  for  neurals.  A  study 
of  the  materials  at  hand  has  convinct  the  writer  that  Professor  Cope  was  nearer  the  truth 
when  he  regarded  this  species  as  a  Dermatemys. 

As  stated,  no  neural  bones  are  preserved.  The  presence  of  a  median  keel  must  rest  on 
Cope's  statement  and  on  the  probability  that  such  a  keel  would  accompany  the  lateral  keels. 
The  latter  were  sharply  defined  (plate  38,  fig.  8)  and  ran  longitudinally  at  a  distance  of  about 
10  mm.  from  the  median  border  of  the  costal  scutes.  Along  this  keel,  on  the  hinder  portion 
of  the  costal  scute  represented,  the  crest  rises  but  little  above  the  surface  of  the  bone;  but 
immediately  behind  the  sulcus  that  separates  this  scute  from  the  next  one  there  is  a  sudden 
depression  of  the  bone,  so  that  the  keel  stands  up  very  prominently.  As  it  is  followed  back- 
ward its  apparent  height  diminishes.  Where  the  sulcus  crosses  the  keel  the  sulcus  bends 
forward,  then  again  backward,  thus  forming  a  sort  of  loop.  One  of  the  costals  present  is  20 
mm.  wide,  the  other  is  18  mm.  The  thickness  through  the  keel  is  6  mm.,  but  this  rapidly 
diminishes  to  about  3  mm.  distally.    The  width  of  the  vertebral  scutes  can  not  be  determined. 


264  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

It  appears  probable  that  the  back  of  this  species  resembled  closely  that  of  Staurotypus  tripor- 
catus,  as  represented  on  plate  XXB  of  Gray's  Catalogue  of  Shield  Reptiles. 

None  of  the  peripheral  bones  at  hand  show  that  there  was  a  dentated  suture  between  them 
and  the  costals.  Those  which  articulated  with  the  plastron  are  thick  and  heavy.  Of  these 
there  were  probably  5  on  each  side.  Plate  38,  figs.  4,  5,  represents  one  which  is  regarded  as 
the  sixth  peripheral  of  the  right  side.  It  is  slightly  larger  than  the  corresponding  one  of  the 
leftside.  The  length  is  22  mm.;  the  thickness  of  the  hinder  end,  17  mm.;  that  of  the  anterior 
end,  10  mm.  The  outer  surface  is  strongly  convex,  and  furnisht  with  a  longitudinal  sharp 
ridge.  The  anterior  portion  of  the  inner  surface  is  concave.  Along  the  lower  border  of  this 
face  are  three  excavations  for  digitations  from  the  hypoplastron.  Near  the  upper  border  is  a 
deep  cylindrical  pit  for  the  extremity  of  a  rib.  The  hindermost  digitation  of  the  hypoplastron 
has  evidently  past  on  to  the  next  peripheral  behind,  probably  the  seventh.  Other  thickened 
peripherals  present  almost  certainly  belonged  farther  forward  and  received  the  digitations  of 
the  hyoplastron.  Between  these  and  the  thickened  peripheral  just  described  there  was  at 
least  I,  probably  2,  thinner  peripherals.  One  of  these,  the  fourth  or  the  fifth,  is  represented 
by  figs.  6  and  7  of  plate  38.  Its  length  is  19  mm.;  its  height,  27  mm.;  its  greatest  thickness 
9  mm.  Its  outer  surface  is  convex  perpendicularly,  and  is  traverst  by  the  continuation  of  the 
ridge  described  as  occurring  on  the  thickened  peripherals.  The  inner  surface  is  concave 
perpendicularly.  In  the  upper  half  of  this  face  is  a  pit  for  a  rib-end;  near  the  lower  border 
are  3  shallow  pits  for  digitations  from  the  plastral  bones.     The  lower  edge  was  connected 

with  the  plastron  by  a  dentate  suture. 

r — T^     "^^^^  This  bone  or  one  similar  to  it  was  con- 

[        /     hyo        i(  nected    partly    with    the    hyoplastron, 

ij;^^^;25i__l____  \  I  partly  with  the  hypoplastron.    Each  of 

"''y/^^^.:,.-"-  ^ — — -^  these  peripherals  is  traverst  by  a  perpen- 

[  ".   hypo  p  dicular  sulcus.    Along  the  upper  border 

I?  y"     ^X^^       \^»,^  runs  a  longitudinal  sulcus  and  along  the 

(         /  \   li^~~y\     lower  border  another,  all  these  forming 

\lv^  ^i^ll.!,' ))     the  boundaries  of  the  marginal  scutes. 

(         //  -^'g-  9  of  ^^  plate  cited  represents 

^^"ccoi/       the  pygal  bone.   Its  length  is  22  mm.,  its 

_  ^^    ,    ,  ,  „        ^  ■  ,    ,        ,  height  18  mm.,  its  greatest  thickness  8 

1*10.  ^2^. — Jtloplochelys  crassa.   Part  of  right  hvoplastron,     „  d  j-     i     1     ^l  r 

»u    1  r.  u         I    .  J         ir        ■  u      1        L  ui      nim-     rerpendicularly  the  outer  face  IS 

the  lett  hypoplastron,  and  one  left  peripheral,  probably  f     .  ■'        ,  , 

the  seventh.     X§.  concave,  the  mner  strongly  convex.    It 

is  doubtful  whether  the  upper  border 
formed  a  jagged  suture  with  the  suprapygal.  Another  free  peripheral,  probably  the  tenth, 
resembles  the  pygal  in  general  features. 

Text-fig.  325  represents  the  left  hypoplastron  attacht  to  the  seventh  peripheral.  Near  the 
hyohypoplastral  suture  and  near  the  midline  the  thickness  of  the  bone  is  9  mm.;  at  the  outer 
extremity  the  thickness  is  4  mm.  At  the  narrowest  portion  the  width  is  11  mm.  The 
bone  was  united  with  the  one  on  the  opposite  side  by  a  coarse  suture;  similarly  with  the 
xiphiplastron.  With  the  thicker  peripherals  it  was  articulated  by  means  of  digitations; 
with  the  intermediate  and  thinner  ones,  by  both  digitations  and  dentated  sutures.  A  pro- 
cess of  the  xiphiplastron  extended  along  the  outer,  hinder  angle  of  the  hypoplastron. 
On  the  lower  surface,  between  the  outer  and  the  middle  thirds  of  the  bone  there  is  seen 
a  shallow  sulcus,  the  inner  boundary  of  an  inframarginal  scute.  Another  sulcus  begins 
at  the  inguinal  notch  and  runs  forward  and  inward  to  the  meeting  of  the  transverse  and 
longitudinal  sutures. 

On  the  left  side  of  the  figure  last  cited  is  represented  the  outer  two-thirds  of  the  hyoplas- 
tron of  the  right  side.  At  the  narrowest  part  the  bone  was  16.5  mm.  wide.  The  bridge  was, 
therefore,  at  its  narrowest  portion,  about  27  mm.  wide.  On  the  outer  end  of  the  bone  are  sulci 
bounding  portions  of  2  inframarginal  scutes.  No  other  sulcus  is  seen  on  this  bone;  and  it  is 
not  probable  that  there  was  one  beginning  at  the  axillary  notch  and  running  backward  and 
inward  to  meet  the  one  from  the  inguinal  notch,  such  as  we  find  in  Chelydra.  The  whole 
arrangement  appears  to  be  like  that  of  Staurotypus  salvinii,  as  represented  by  Dr.  Boulenger 
in  his  Catalogue  of  Chelonians. 


DERMATEMYDID^. 


265 


The  xiphiplastra  were  evidently  small  bones,  but  there  is  no  remnant  of  them  preserved. 

The  width  of  the  shell  of  this  specimen  was  about  130  mm.  An  estimate  based  on  the 
width  of  the  two  costal  plates  shows  that  the  length  was  approximately  185  mm.  The  animal 
was  therefore  somewhat  broader  relatively  than  either  Staurotypus  salvinii  or  S.  triporcatus. 

So  far  as  known,  this  species  differs  from  H.  saliens  in  having  the  bones  of  the  plastron 
less  firmly  sutured  with  the  peripherals  and  in  having  the  latter  bones,  at  least  those  of  the 
bridge  region,  without  close  suture  with  the  costals.     The  bridge  is  much  narrower. 

Hoplochelys  saliens  sp.  nov. 
Text-figs.  3x6,  327. 

The  only  specimen  of  this  species  at  present  known  was  found  by  Dr.  J.  L.  Wortman 
in  1896,  at  the  head  of  the  Escavada  Canyon,  Rio  Arriba  County,  New  Mexico,  in  Torrejon 
deposits.     It  belongs  to  the  American  Museum  of  Natural  History  and  bears  the  number 


326. 


Figs.  326  AND  327. — Hoplochelys  saliens.    Carapace  and  plastron  of  type.     Xj.    Restored 

portions  in  interrupted  lines. 

326.  Carapace.  327.  Plastron  and  part  of  carapace. 

1200.  The  shell,  the  only  portion  preserved,  is  considerably  crusht,  but  is  nearly  all  present. 
The  only  parts  missing  are  portions  of  the  seventh  and  eighth  costals,  the  hindermost  neurals, 
and  some  portions  of  the  plastron.  Unfortunately  for  an  understanding  of  the  structure  of 
the  shell  much  of  it  was  covered  by  a  very  refractory  matrix,  which  adhered  so  closely  that  it 
had  to  be  ground  away  to  the  bone.  As  a  result,  it  is  difficult  to  determine  in  many  places 
the  position  of  the  boundaries  of  the  scutes  and  sometimes  of  the  sutures.  Most  of  the  periph- 
erals, however,  have  been  beautifully  weathered  out  and  preserved. 

In  form  the  carapace  (fig.  326)  was  oval,  rounded  in  front  and  behind,  and  apparently  of 
some  considerable  elevation.  The  total  length  was  close  to  325  mm.;  the  width,  close  to  200 
mm.    There  was  a  median  keel  of  moderate  height.    On  each  side  of  this,  at  a  distance  of  50 


266  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

mm.  in  front,  30  mm.  behind,  there  was  a  more  prominent  lateral  keel.  Along  none  of  these 
keels  was  the  bone  suddenly  sunken  just  behind  the  transverse  sulci,  as  it  is  in  H.  crassa. 
In  addition  to  these  keels,  there  is  on  each  side,  on  the  bridge  peripherals,  a  narrow  ridge 
which  passes  in  front  and  behind  into  the  free  edges  of  the  peripherals. 

The  rim  of  the  carapace  was  formed  by  a  nuchal,  probably  ten  pairs  of  peripherals,  and 
a  pygal.  The  nuchal  is  excavated  in  front  for  the  neck.  The  width  in  front  is  43  mm,;  its 
thickness  is  11  mm.;  its  length  can  not  be  determined.  The  first  peripheral  is  32  mm.  long 
on  the  free  border  and  38  mm.  high.  The  second  peripheral  is  35  mm.  long,  concave  above, 
convex  below,  and  with  an  acute  border.  Farther  backward  this  border  runs  into  the  rather 
sharp  keel  running  along  near  the  upper  border  of  the  bridge  peripherals.  The  upper  border 
of  the  bridge  peripherals  is  plane,  continuous  with  the  surface  of  the  costals,  and  10  mm. 
or  less  wide.  At  the  bottom  of  this  surface  just  above  the  keel  before  mentioned  run  the 
sulci  separating  the  costal  scutes  from  the  marginals.  Immediately  below  the  lateral 
keel  the  peripherals  thicken  suddenly  and  form  a  sort  of  roll  along  the  shell.  The  form  of 
this  roll  may  be  seen  from  the  section  of  the  peripheral  of  the  next  species,  H.  paludosa. 
The  peripherals  behind  the  bridge  are  slightly  flared  upward  and  are  acute-edged.  The 
width  and  length  of  the  pygal  can  not  be  determined.  The  hinder  border  of  the  carapace 
was  not  notcht. 

The  anterior  costal  plate  had  a  width  of  about  50  mm.;  the  next  3  or  4  pairs,  a  width  of 
35  mm.  or  a  little  more.  The  costals  opposite  the  bridges  have  a  thickness  of  7  mm.  at  their 
distal  ends. 

The  neurals  are  broad,  and  with  the  broader  end  forward.  The  second  has  a  width  of 
about  35  mm.;  the  third  about  the  same  width;  the  fourth  a  width  of  25  mm.  The  boundaries 
of  those  behind  these  can  not  be  determined.  The  second  vertebral  scute  has  a  width  of 
about  75  mm.;   the  succeeding  ones  are  narrower. 

The  anterior  lobe  of  the  plastron  (fig.  327)  is  about  100  mm.  wide  at  the  base.  It  appears 
probable  that  the  epiplastrals  are  missing.  The  entoplastron  appears  to  have  the  form 
and  size  represented  in  the  figures.  The  epiplastra  were  probably  in  contact  with  the  outer 
border  of  the  hyoplastra  as  in  Staurotypus  salvinii  (Boulenger's  Catalogue,  p.  31).  The  bridge 
has  a  width  of  about  60  mm.,  a  little  more  than  half  of  which  is  furnisht  by  the  hyoplastron. 

The  hinder  lobe  of  the  plastron  is  about  70  mm.  wide  at  the  base.  The  suture  between 
the  hypoplastra  and  the  xiphiplastra  was  probably  where  shown  in  the  figures,  but  this  is  not 
certain.    The  xiphiplastra  probably  came  to  a  point  posteriorly. 

Of  Staurotypus  salvinii,  Sumichrast  says  (Bull.  Soc.  Zool.  France,  1880,  p.  169)  that  it 
lives  in  muddy  pools.  Its  food  consists  of  small  aquatic  animals,  especially  of  mollusks 
belonging  to  the  genus  Atnpullaria.  Its  disposition  is  voracious  and  irritable.  Its  gait  on 
land  is  free,  and  it  runs  with  some  swiftness,  a  fact  due  to  the  form  of  the  plastron,  which 
leaves  to  the  limbs  freedom  of  motion. 

The  small  posterior  lobe  of  the  plastron  of  Hoplochelys  indicates  that  the  hinder  limbs 
were  strong  and  endowed  with  freedom  of  movement.  Its  habits  and  disposition  may  have 
been  not  greatly  different  from  those  of  Staurotypus. 

Hoplochelys  paludosa  sp.  nov. 
Fig.  328. 

This  species  is  based  on  a  single  peripheral  bone,  probably  the  seventh  of  the  left  side. 
It  was  found  by  Mr.  Barnum  Brown,  in  1904,  in  Escavada  Canyon,  New  Mexico,  where  H. 
saliens  was  discovered.  It  belongs  to  the  American  Museum  of  Natural  History  and  has  the 
number  6079.  It  differs  from  the  latter  species  in  lacking  the  longitudinal  ridge  along  the 
convexity  of  the  outer  surface  of  the  peripherals,  and  in  having  the  suture  with  the  costals 
much  higher  above  the  costo-marginal  sulci.  In  the  present  species  this  suture  is  at  a  distance 
of  20  mm.  above  the  sulcus,  while  in  H.  saliens  it  is  only  10  mm.  or  less.  The  absence  of  the 
peripheral  carina  is  regarded  as  an  important  specific  character.  The  size  of  the  individual 
has  been  probably  slightly  less  than  that  of  H.  saliens,  the  length  of  the  seventh  peripheral 
of  the  latter  being  35  mm.;    of  H.  paludosa,  32  mm. 


dermatemydida:. 


267 


From  H.  crassa  the  present  species  differs  in  having  the  supposed  seventh  peripheral 
strongly  sutured  to  the  contiguous  costal  bone,  in  having  no  lateral  carina,  and  in  having  the 

longitudinal    sulcus    at    the    middle    of    the 
height,  instead  of  near  the  costal  border. 

In  the  inner  face  of  the  bone  are  excava- 
tions for  the  reception  of  digitations  from  the 
plastron.  One  of  these  digitations  remains  in 
position,  and  shows  that  it  extended  backward 
ashortdistanceintotheeighth  peripheral.  The 
border  which  articulated  with  the  costals  is  7 
mm. thick.  In  the  sutural  edge  is  a  deep  pit,  10 
mm.  in  diameter,  which  received  the  extremity 
of  the  rib  of  the  contiguous  costal  plate. 

Fig.   328   shows   the   type   peripheral  as 
seen  from  the  outside.     The  drawing  on  the 
right  presents  a  view  of  the  hinder  end  of  the  bone;   the  one  on  the  left,  the  anterior  end. 


Fig.    328. — Hoplochelys   paludosa.     Supposed    left 
seventh  peripheral  forming  type.  X§.  A.M.N.H. 

a,  bone  seen  from  side;   h,  anterior  end;  c,  posterior  end;  d,  an 
adhering  fragment  of  the  plastron. 


Genus  KALLISTIRA  nov. 

Carapace  thick  and  solid;  provided  with  a  median  and  two  lateral  carinas.  Plastron 
unknown,  except  that  its  inguinal  buttresses  were  extensively  developt  and  ascended  a  con- 
siderable distance  against  the  inner  surface  of  the  fifth  and  sixth  costals. 

Type :    Dermatemys  costilatus  Cope. 

Kallistira  costilata  (Cope). 

Figs.  329-334. 

Dermatemys?  costilatus,  CoPE,  Syst.  Catalogue  Vert.  Eocene,  N.  Max.,  1875,  p.  36. 

Dermatemys  costilatus,  CoPE,  Report  on  Geol.  N.  Mex.,  1874  (1875),  p.  96;  Wheeler's  Surv.  100  Merid., 

IV,  pt.  ii,  p.  52,  plate  xxiv,  figs.  17-31. 
Baptemys  costilatus.  Hay,  Bibliog.  and  Cat.  P"oss.  Vert.  N.  A.,  1902,  p.  445. 

The  types  of  the  present  species  belong  to  the  U.  S.  National  Museum  and  bear  the  number 
II 52.  Not  all  the  fragments  that  Cope  figured  are  present.  Those  missing  are  the  originals 
of  Cope's  figs.  17,  20,  23,  24,  26,  and  31.  Cope  states  that  he  had  fragments  representing  6 
individuals,  and  that  parts  ot  4  were  figured.  There  appears  to  be  no  reason  for  doubting 
that  all  of  these  individuals  belonged  to  the  same  species.  Figures  of  some  portions  of  these 
types  are  here  presented.    The  species  was  found  in  the  Wasatch  beds  of  New  Mexico. 

The  species  is  characterized  by  its  thick  and  heavy  shell  and  the  presence  of  at  least  3 
carinae  on  the  carapace,  one  running  along  the  midline  and  one  on  each  side  of  it. 

The  fragment  which  furnisht  Professor  Cope's  figs.  27  and  28  belongs  to  the  upper  end  of 
a  costal,  probably  either  the  second  or  the  fourth.  Cope's  fig.  27  (fig.  329)  is  inverted  on 
his  plate.  The  width  of  the  costal  is  20  mm.  It  is  crost  by  a  low  keel  whose  breadth  is  almost 
9  mm.,  but  whose  elevation  is  scarcely  a  millimeter;  the  thickness  of  the  costal  above  the  carina 
being  6  mm.,  that  thru  the  carina,  7  mm.  At  the  distal  end  of  the  fragment  the  thickness 
is  5  mm.  This  piece  of  costal  presents  a  part  of  the  sulcus  bounding  a  vertebral  scute  laterally 
and  the  sulcus  running  down  the  costal.  .These  are  extremely  narrow  and  shallow.  The 
longitudinal  sulcus  is  at  a  maximum  distance  of  10  mm.  from  the  proximal  border  of  the  costal 
and  above  the  lateral  carina.  The  vertebral  scutes  appear  to  have  had  a  width  of  about 
42  mm.  The  proximal  end  of  the  costal  is  rounded,  showing  that  the  lateral  borders  of  the 
adjacent  neural  were  concave.  Another  costal,  the  one  furnishing  Cope's  figs.  19  and  19a, 
belonged  to  a  smaller  individual.  The  carina  is  still  less  conspicuous  than  in  the  case  of  the 
one  just  described.  The  original  of  Cope's  fig.  21  (fig.  330)  has  the  carina  more  sharply 
defined  and  with  a  width  of  5  mm.  It  is  probable  that,  as  suspected  by  Cope,  the  carinae 
were  developt  on  the  rear  of  the  animal  and  disappeared  anteriorly. 

Fig.  331  represents  the  original  from  which  Cope  obtained  his  fig.  30.  It  is  a  portion  of  the 
distal  half  of  a  costal,  in  all  probability  the  fifth  of  the  right  side.    The  extreme  end  of  the  bone 


268 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


appears  to  be  missing.  The  figure  presents  the  inner,  or  visceral,  surface.  This  bone  is  4  mm. 
thick  at  its  anterior  border,  but  toward  the  other  border  it  thickens  greatly,  so  that  a  little 
beyond  the  middle  of  the  width  the  thickness  is  10  mm.  From  the  line  of  its  greatest  thickness 
the  bone  is  beveled  off  on  the  inner  side  to  its  hinder  border,  and  against  this  beveled  surface 
the  sixth  costal  has  articulated.  A  strongly  developt  buttress  from  the  plastron  ascended 
against  the  inner  surfaces  of  these  two  costals  at  their  junction.  The  scar  for  this  buttress  on 
the  fifth  costal  here  figured  is  20  mm.  long.    The  plastron  was  therefore  articulated  with  the 


331-  33°-  329- 

Figs.  329-331- — KalUstira  costilata.     Costals  of  the  type.      Xl. 

329.  Proximal  end  of  costal,  second  or  fourth. 

330.  Proximal  end  of  costal,  showing  a  carina. 

331.  Distal  end  of  costal,  probably  the  fifth,  showing  scar 

for  inguinal  buttress  of  plastron. 

carapace  in  a  very  different  way  from  that  seen  in  other  dermatemyds;  and  a  distinct  genus 
is  indicated. 

Portions  of  3  neurals  are  at  hand,  those  represented  by  Cope's  figs.  18,  22,  and  25.  The 
first-mentioned  (fig.  332)  has  a  width  of  22  mm.,  probably  belonged  well  forward,  and  was 
possibly  the  second.  The  median  carina  is  barely  perceptible.  No  sulcus  crosses  the  portion 
present.  That  part  of  a  neural  from  which  Cope's  fig.  25  was  drawn  (fig.  332^)  is  narrow  and 
devoid  of  a  carina.  It  is  crost  near  the  fracture  by  a  narrow  and  shallow  sulcus.  It  appears  quite 
probable  that  this  is  the  posterior  end  of  the  first  neural.    At  its  lateral  border  it  is  5  mm.  thick. 

The  neural  represented  by  Cope's  fig.  22  (fig.  333)  apparently  belonged  to  the  rear  of  the 
carapace,  and  resembles  closely  the  sixth  of  Staurotypus  salvinii.     Its  length  is   18  mm.; 


332-  332a.  333.  334.  334a- 

Figs.  332-334. — KalUstira  costilata.     Neurals  and  a  peripheral  of  type.      Xi. 

332.  332(3.   Portions  of  two  neurals  of  the  type.     332  is  Cope's  fig.  18; 

332a  Cope's  fig.  25. 

333.  A  hinder  neural,  showing  carina.     Cope's  fig.  22. 

334.  A  hinder  peripheral  with  a  section  {a)  across  it. 

greatest  breadth  about  20  mm.;  thickness  at  the  lateral  border  4.5  mm.,  through  the  carina 
0.5  mm.    The  carina  is  sharply  defined  and  wider  in  front  than  behind. 

A  portion  of  a  hinder  peripheral  is  present,  being  the  original  of  Cope's  figs.  29  and  29a, 
and  constituting,  according  to  Cope,  a  portion  of  the  same  individual  as  those  furnishing  his 
figs.  27  and  30.  Cope's  figure  is  inverted.  This  (fig.  334)  bone  has  a  height  of  27  mm.  in  a 
direct  line,  and  a  maximum  thickness  of  7  mm.  Its  width  can  not  be  determined,  as  the  bone 
has  been  broken  near  the  descending  sulcus.  This  sulcus,  in  contradistinction  to  those  of  the 
costals  and  neurals,  is  broad  and  deeply  and  irregularly  imprest.  Along  the  upper  border  of 
the  bone  runs  what  appears  to  be  the  longitudinal,  or  costo-marginal,  sulcus.     On  the  under 


DERMATEMYDID^.  269 

side  of  the  bone  the  descending  sulcus  is  narrow  and  shallow,  like  those  of  the  costals.  This 
bone  is  strongly  concave  on  the  upper  surface  and  has  an  acute  free  border.  It  was  very 
loosely  articulated  with  the  contiguous  costal;  and  in  the  upper  border  there  is  a  pit  for  the 
extremity  of  the  costal  rib.     Fig.  334a  is  a  section  of  this  bone. 

Professor  Cope  thought  that  this  species  attained  about  the  size  of  Baptemys  luyoming- 
ensis,  but  none  of  the  bones  described  by  him  indicates  a  size  so  great.  From  the  width  of  the 
costal  represented  by  fig.  331  the  writer  estimates  the  length  of  the  carapace  at  something  less 
than  200  mm. 

Genus  NOTOMORPHA  Cope. 

A  little-known  genus.     Anterior,  and  probably  posterior,  peripherals  with  obtuse  free 
borders.     Apparently  intergulars  large;    the  gulars  small  and  removed  far  from  the  midline. 
Type:    Notomorpha  gravis  Cope. 

The  materials  on  which  the  genus  Notomorpha  was  based  are  in  the  U.  S.  National 
Museum.  In  the  original  description  of  the  genus  (Proc.  Amer.  Philos.  Soc,  xii,  1872,  p.  474) 
characters  were  attributed  to  it  which  were  derived  from  bones  of  the  species  called  in  the 
present  work  Echmatemys  testudinea.  These  bones,  altho  portions  of  the  first  costals  with 
articular  scars  for  axillary  buttresses,  were  supposed  by  Cope  to  be  xiphiplastrals  with  scars 
for  the  pubis.  On  the  strength  of  these,  the  genus  was  assigned  to  the  Pleurodira.  Cope's 
discovery  of  his  error  regarding  the  character  of  the  plastron,  his  removal  of  his  species  testu- 
dinea to  Ernys,  and  his  reduction  of  the  species  A^.  garmanii  to  a  synonym  o{  N.  gravis,  left 
the  latter  the  type  of  the  genus.  This  he  concluded  was  also  a  member  of  the  Emydidae,  but 
associated  with  Dermatemys  and  Agomphus.  As  the  dermatemyd  turtles  are  now  regarded  as 
a  distinct  family,  Notomorpha  must  be  arranged  in  that  family. 

As  stated  above.  Cope  made  his  N .  garmanii  a  synonym  of  N .  gravis,  a  proper  course  in 
case  there  is  only  a  single  species  involved;  but  of  this  there  may  be  permitted  grave  doubts. 
Of  his  gravis  he  described  a  hyoplastron  and  an  epiplastral  of  one  individual  and  a  costal  of 
what  was  doubtfully  another.  The  costal  had  a  width  of  58  mm.,  which  indicated  a  very  large 
turtle.  Cope  at  first  recognized  important  differences  between  the  epiplastrals;  but  later  he 
considered  these  of  less  importance.  We  may,  then,  have  doubts  regarding  the  specific  iden- 
tity of  the  two  lots  of  bones.     Besides  this,  the  materials  figured  all  belong  to  his  A'^.  garmanii. 

Notwithstanding  all  this,  until  future  discoveries  shall  have  thrown  additional  light  on 
Notomorpha,  it  will  be  best  to  place  the  few  known  remains  under  the  specific  name  gravis. 

Notomorpha  gravis  Cope. 

F'gs-  335.  336- 

Notomorpha  gravis,  CoPE,  Proc.  Amer.  Philos.  Soc,  Xll,  1872,  p.  476. 
Notomorpha  garmanii.  Cope,  Proc.  Amer.  Philos.  Soc,  xil,  1872,  p.  477. 
Emys  gravis,  CoPE,  Sixth  Ann.  Report  U.  S.  Geol.  Surv.  Terrs.,  1872  (1873),  p.  626. 
Notomorpha  gravis,  CoPE,  Vert.  Tert.  Form.  West,  1884,  p.  143,  plate  xxiii,  figs.  14-16. — Hay,  Bibliog. 
and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  448. 

The  bones  on  which  Notomorpha  gravis  was  based  appear  to  have  been  lost.  Those 
which  Cope  described  as  N.  garmanii  are  now  in  the  U.  S.  National  Museum,  some  of  these 
bearing  the  number  4103;  others,  belonging  apparently  to  the  same  individual,  have  the 
number  4129.  It  is  not  known  whether  all  the  bones  accompanying  the  figured  specimens 
belonged  to  the  same  individuals  or  even  the  same  species.  We  shall  have  to  regard  as  types 
the  remains  which  were  figured  by  Cope.  All  three  of  these  are  numbered  4103.  The  bones 
originally  described  under  the  two  specific  names  had  been  discovered  in  the  Wasatch  beds 
at  a  point  near  Bear  River,  6  miles  north  of  Evanston,  Wyoming. 

The  bone  which  was  regarded  as  characteristic  o( Notomorpha  is  the  supposed  epiplastron, 
the  subject  of  Cope's  fig.  14,  plate  xxiii,  of  his  work  on  The  Vertebrata  of  the  Tertiary  For- 
mations of  the  West.  The  writer  has  been  unable  to  convince  himself  that  this  is  the  epi- 
plastron, altho  it  may  be  such.  It  may  be  a  first  peripheral.  The  upper  border  of  the  original 
of  Cope's  fig.  14,  which  was  supposed  to  be  the  front  of  the  lip,  has  the  appearance  of  having 


270 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


been  a  sutural  edge  for  articulation  with  another  bone.  The  border  between  the  supposed 
gular  scutes  is  broken  off.  If  the  bone  is  an  epiplastron  it  must  once  have  projected  con- 
siderably at  this  point,  and  the  front  of  the  anterior  lobe  was  deeply  emarginated.  The  length 
of  the  bone  is  about  40  mm.;  its  thickness  behind  is  1 1  mm.  In  case  the  bone  is  an  epiplastron, 
the  lip  was  about  40  mm.  wide.  The  free  border  of  the  bone,  that  represented  by  the  right 
side  of  the  figure,  is  thick  and  obtuse.  That  of  the  same  bone  in  Cope's  type  of  AT.  gravis,  as 
originally  described,  was  acute.  In  his  last  description  of  these  bones  this  difference  appears 
to  have  been  thought  of  no  specific  importance.  On  the  supposed  under  side  of  the  bone  are 
seen  distinct  sulci,  indicating  the  supposed  intergulars  and  the  small  triangular  gulars.  If 
such  they  are,  affinity  with  the  Dermatemydidae  is  indicated.  Whether  or  not  the  intergular 
was  divided  at  the  midline  we  can  not  determine. 

Fig.  335  represents  the  third  left  peripheral  (No.  4129,  U.  S.  N.  M.)  seen  from   above, 
while  fig.  336  presents  a  view  of  the  sutural  end  which  joins  the  second  peripheral.    It  is  seen 

that  the  free  border  is  obtuse.  The  costo-marginal 
sulci  ran  along  not  far  below  the  upper  margin  of  the 
bone.  The  bone  is  39  mm.  high,  36  mm.  along  the 
free  border,  and  18  mm.  thick.  Cope  figures  2  periph- 
erals, but  the  free  borders  were  missing  in  both. 

Cope's  fig.  15  is  said  to  represent  the  posterior 
edge  of  the  eighth  peripheral  of  the  right  side;  but  it 
belonged  to  the  left  side.  This  bone  was  somewhat 
recurved;  its  height  is  about  44  mm.;  its  length  on 
the  free  border  35  mm.;  its  thickness  about  9  mm.  at 
the  border  represented.  The  articular  border  for 
union  with  the  costals  was  thin. 

The  seventh  peripheral  (Cope's  fig.  16)  is  stated 
to  have  been  42  mm.  wide,  45  mm.  high,  and  15  mm. 
thick.  This  peripheral,  the  seventh  of  the  left  side, 
entered  into  the  inguinal  notch.  Its  free  border  was  acute;  its  upper  articular  border  was  thin. 
Besides  these  peripherals,  Cope  had  others  belonging  to  the  bridge  region.  These  he  states 
had  very  obtuse  free  borders.  The  general  massiveness  of  these  was  in  contrast  with  the  thin- 
ness of  the  costals.  The  surface  of  the  peripherals  is  said  to  have  been  obsoletely  rugose. 
A  vertebral  bone  is  stated  to  have  been  7  mm.  thick. 


Figs.  335  and  336. — Notomorpha  gravis. 
View  of  third  left  peripheral  of  the 
type,  with  section.      X§. 

335.  Peripheral  seen  from  without. 

336.  Section  at  anterior  end. 


Genus  BAPTEMYS  Leidy. 

Plastron  united  with  the  carapace  by  means  of  sutures  and  by  axillary  and  inguinal 
buttresses,  which  rise  to  the  lower  borders  of  the  costals  or  beyond.  Plastral  lobes  short  and 
narrow,  the  hinder  not  notcht.  Nuchal  bone  with  short  costiform  processes.  A  full  set  of 
neurals.  Marginal  scutes  not  encroaching  on  the  costal  bones.  Intergulars,  gulars,  and 
humerals  of  each  side  usually  consolidated  into  one  scute.    Inframarginals  present. 

Type:    Baptemys  wyomingensis  Leidy. 

This  is  the  only  genus  of  the  Dermatemydidae  which  possesses  a  full  series  of  neurals. 
The  pectoral  scutes  appear  to  have  extended  themselves  forward  to  the  epiplastrals  and  even 
further.  The  region  which  in  Adocus  is  occupied  by  the  intergulars,  gulars,  and  humerals  of 
each  side  presents  usually  only  a  single  scute;  but  in  a  specimen  of  B.  tricarinata  (fig.  348)  the 
gulo-humeral  sulcus  is  partly  developt. 

This  genus  is  represented  by  3  known  species.  Of  these,  one,  B.  fluviatilis,  comes  from 
uncertain  locality  and  level.  Of  the  others,  B.  tricarinata  belongs  to  the  Wind  River  beds, 
while  B.  tuyomingensis  is  common  in  the  Bridget  beds  of  southwestern  Wyoming. 

Baptemys  wyomingensis  Leidy. 
Plate  37,  figs.  II-13;  plate  38,  fig.  10;  plate  40,  fig.  1;  plate  41,  figs,  i,  2;  text-figs.  337-345- 

Baptemys  wyomingensis,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phiia.  1870,  p.  5;  Ann.  Report  U.  S.  Gaol.  Surv. 
Wyoming,  etc.,  1870  (1871),  p.  367;  Ann.  Report  U.  S.  Geol.  Surv.  Montana,  etc.,  1872,  p.  367; 
Contrib.  Ext.  Fauna  West  Terrs.,   1873,  pp.   157,  340,  plate  xii,  plate  xv,  fig.  6. — Cope,  Ext. 


DERMATEMYDIDil. 


271 


Batrach.  Reptilia,  Aves  N.  A.,  1869  (1870),  p.  ii. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902, 

p.  445;  Amer.  Jour.  Sci.  (4),  xvin,  1904,  p.  265,  plate  xiii,  figs.  1-3,  text-fig.  2;  Amer.  Geologist, 

XXXV,  1905,  p.  331. 
Adocus  vyomingensis,  CoPE,  Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1870,  p.  233;  Proc.  Amer.  Philos.  See, 

XI,  1870,  p.  297. 
Dermatemys  wyomingensis.  Cope,  6th  Ann.  Report  U.  S.  Geol.  Surv.  Terrs.,  1872  (1873),  p.  624;  Amer. 

Naturalist,  xvi,  1882,  p.  991,  fig.  9. 
Dermatemys  vyomingensis,  CoPE,  Vert.  Tert.  I'orm.  West,  1884,  p.  142. 
Ba'ena  ponJerosa,  Cope,  6th  Ann.  Report  U.  S.  Geol.  Surv.  Terrs,  1872  (1873),  p.  624. 
Ba'ena?  ponderosa,  Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1903,  p.  438. 

The  type  of  the  present  species  belongs  to  the  Academy  of  Natural  Sciences  at  Phila- 
delphia. The  specimen  was  obtained  somewhere  in  the  neighborhood  of  Fort  Bridger, 
Wyoming,  from  which  locality  probably  all  the  known  specimens  have  been  derived.  The 
level  is  therefore  that  of  the  lower  portions  of  the  Bridger  beds.  Of  the  type,  some  of  the 
peripherals  are  missing,  also  the  front  of  the  plastron.  The  total  length  of  the  carapace  in 
life  was  nearly  450  mm.;  the  breadth,  about  310  mm.  On  the  hinder  third  of  the  carapace 
there  is  a  prominent  carina,  the  summit  of  which  is  flat.  The  anterior  neurals  are  considerably 
longer  than  wide,  with  the  broader  end  directed  forward.  The  free  borders  of  the  anterior 
peripherals  are  thickened  and  obtuse.  The  surface  of  the  carapace  is  mostly  smooth,  but  pos- 
teriorly somewhat  corrugated.    The  dimensions  of  the  vertebral  scutes  are  given  in  the  table. 

The  plastron  is  relatively  small,  and 


Vertebrals  of         | 

Neurals  of  1494 

Vertebrals  of 

type. 

A.MJI.H. 

1494A.M.N.H. 

No. 

Length. 

i 
Width. 

No.     Length. 

Width. 

No.     Length.  Width. 

I 

81 

108 

5° 

22 

I           68         90 

2 

104 

62 

4» 

22 

2          85         53 

3 

90 

68 

1 

45 

21 

3          83         55 

4 

79 

66 

40 

22 

4           86         60 

s 

4» 
37 
»5 

23 
28 
28 

5         no        104 

1             1 

'7-5 

27 

1        !        ! 

large  spaces  are  left  between  it  and  the 
carapace,  thus  favoring  the  movements 
of  the  legs.  The  anterior  lobe  is  148 
mm.  wide  at  the  base.  The  bridge  has  a 
width  of  105  mm.  The  hinder  lobe  ter- 
minates obtusely  behind.  The  length  is 
94  mm.;  the  width  at  the  base,  115  mm. 
On  each  of  the  bridges  are  3  inframar- 
ginal  scutes.  Of  these  the  hindermost 
extends  forward  on  the  hyoplastron. 

Dr.  Leidy  described  a  second  spec- 
imen which  had  been  discovered  at 
Church  Buttes.  This  shell  was  impor- 
tant because  it  furnisht  the  front  of  the  plastron,  which  Leidy  figured  in  his  Contributions 
(plate  XV,  fig.  6).  This  front,  however,  differs  so  much  from  that  of  all  others  found  since, 
that  there  is  some  reason  for  suspecting  that  it  belongs  to  a  distinct  species,  being  truncated 
and  notcht  in  front.     Below  some  details  are  given  regarding  this  specimen. 

In  the  Cope  collection  belonging  to  the  American  Museum  of  Natural  History  is  a  large 
specimen  which  presents  the  carapace  (plate  40,  fig.  I ;  text-fig.  337);  but  of  the  plastron  there 
is  only  the  impression  of  the  hinder  lobe  on  the  matrix.  The  catalog  number  is  1494.  Were 
it  not  that  Cope  describes  the  form  of  the  anterior  lobe,  it  might  be  supposed  that  it  is  the 
specimen  mentioned  by  him  in  the  Proceedings  of  the  American  Philosophical  Society  (vol. 
XI,  p.  297).  It  is  possible  that  that  author  did  not  intend  to  state  that  his  specimen  possest 
this  lobe,  but  referred  to  what  Dr.  Leidy  had  determined.  The  total  length  of  the  carapace  is 
435  mm.,  in  a  straight  line;  the  width  is  283  mm.;  and  the  height,  about  180  mm.  The 
specimen  is  remarkable  for  its  narrowness.  The  anterior  edge  is  thickened  and  rounded  like 
the  edge  of  one's  little  finger.  The  thickness  of  the  first  peripheral  is  16  mm.  The  hinder 
free  borders  are  also  obtuse,  but  much  thinner,  the  thickness  near  the  edge  of  the  tenth  being 
7  mm.;  but  this  increases  to  14  mm.  at  half  the  height  of  the  bone.  The  neurals  are  narrow. 
The  dimensions  of  the  neurals  and  the  vertebral  scutes  are  presented  in  the  table  above. 

There  are  12  pairs  of  marginal  scutes.  The  costo-marginal  sulcus  runs  considerably  below 
the  costo-peripheral  suture.  There  appears  to  be  present  a  ninth  pair  of  costal  plates  (fig.  337, 
f./>.?9). 

The  American  Museum  expedition  of  1903  secured  2  specimens  of  this  species  at  Grizzly 
Buttes.    These  have  the  catalog  numbers  5934  and  5967.    No.  5967  presents  a  large  portion 


y 


^1^ 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


of  the  skull.  The  shell  of  both  specimens  is  quite  complete.  In  neither  is  the  front  of  the 
plastron  truncated.  The  length  of  the  carapace  of  No.  5967  (plate  41,  figs.  I,  2)  was  originally 
close  to  430  mm.;  its  width  about  330  mm.;  but  the  shell  has  been  strongly  crusht  down- 
ward. The  first  vertebral  scute  has  a  width  anteriorly  of  80  mm.;  the  next  three,  each  a  width 
of  about  56  mm.;  the  fifth,  a  width  of  128  mm.  posteriorly.  It  will  be  observed  that  the  last 
of  these  vertebrals  is  considerably  wider  than  in  the  Cope  specimen.  On  the  hinder  half  of 
the  carapace  there  is  seen,  on  each  side  of  the  vertebral  scutes,  an  indistinct  flattened  carina. 
These  correspond  to  the  much  more  prominent  lateral  keels  seen  in  the  predecessor  of  this 
species,  B.  tricarinata. 

The  anterior  lobe  of  the  plastron  is  100  mm.  long  and  152  mm.  wide  at  the  base.  The 
lateral  borders  converge  in  nearly  straight  lines  to  opposite  the  front  of  the  entoplastron; 
then  they  round  rapidly  to  the  midline.  The  entoplastron  is  large,  62  mm.  long  and  67  mm. 
wide.    The  bridge  is  117  mm.  wide.    The  hinder  lobe  is  92  mm.  long  and  130  mm.  wide  at 


Figs.  337  and  338. — Baptemys  wyomingensis.     Carapace  and  plastron. 

337.  Carapace.    Xi.    No.  1494  A.M.N. H.    c. /i.  9,  probable  ninth  pair  of  costal  bones. 

338.  Plastron  and  border  of  carapace.    X/s-    Specimen  in  Yale  University. 

the  base.  As  in  other  known  specimens,  the  intergulars,  gulars,  and  humerals  appear  to  have 
coalesct.  The  humero-pectoral  sulcus  crosses  the  entoplastron  a  little  behind  its  middle,  and 
on  the  hyoplastron  it  turns  abruptly  forward  and  outward.  The  anal  scutes  measure  51  mm. 
on  the  midline.  Each  of  the  other  pairs  measure  about  62  mm.  On  each  bridge  there  are  3 
inframarginals,  as  in  the  type  of  the  species.  The  hindermost  one  is  1 10  mm.  long  on  its 
outer  border. 

The  specimen  numbered  5934  differs  from  the  one  just  described  in  having  the  first 
vertebral  scute  unusually  wide,  125  mm.  The  lateral  borders  of  the  anterior  lobe  of  the 
plastron  are  not  so  straight  as  in  No.  5967  and  the  extremity  is  slightly  more  pointed.  The 
inframarginals  are  as  in  the  latter.    This  specimen  shows  well  the  buttresses.    The  axillary 


DERMATEMYDID^.  2/3 

bones  ascend  to  the  borders  of  the  first  costals.    The  inguinal  buttresses  do  not  reach  the 
upper  borders  of  the  peripherals. 

At  Yale  University  is  a  specimen  (No.  484)  which  was  collected  in  1870,  at  Millersville, 
Wyoming,  therefore  in  the  lower  third  of  the  Bridger  deposits.  It  furnishes  a  crusht  carapace 
and  a  complete  plastron  ftext-fig.  338),  the  nearly  complete  skull  fplate  37,  figs.  11,  12,  13), 
and  portions  of  limb  bones.  The  carapace  has  a  length  of  445  mm.  and  a  width  of  330  mm. 
There  is  a  large  suprapygal  45  mm.  long  and  70  mm.  wide.  The  first  vertebral  scute  is  100 
mm.  wide;  the  second,  52  mm.;  the  third,  50  mm.;  the  fourth,  66  mm.;  the  fifth,  95  mm. 
Besides  these  normal  vertebrals  there  is  a  small  supernumerary  one,  37  mm.  long,  cut  off  from 
the  front  of  the  normal  fifth.  The  plastron  (fig.  338)  is  305  mm.  long.  As  will  be  seen  from 
the  figure,  there  are  on  each  bridge  4  inframarginals.  A  small  one  appears  to  have  been  cut 
off  from  the  anterior  end  of  the  large  third  one  of  other  specimens.  In  this  specimen  the 
anterior  extremity  of  the  plastron  comes  forward  as  far  as  the  front  of  the  carapace;  but  this 
is  doubtless  due  to  crushing. 

A  specimen  at  Princeton  University,  No.  10074,  is  half  as  high  as  long. 

Dr.  Leidy's  second  specimen,  the  one  which  furnisht  the  truncated  anterior  lobe  of  the 
plastron,  is  in  the  U.  S.  National  Museum  and  has  the  number  5000.  In  all  respects,  except 
the  form  of  this  lobe,  the  specimen  agrees  with  typical  specimens  of  B.  luyomingensts.  The 
plastron  alone  is  represented  and  of  this  a  portion  of  the  hinder  lobe  is  missing.  The  length 
of  the  anterior  lobe  is  93  mm.;  its  width  at  the  base  145  mm.;  width  at  the  epiplastral  sutures, 
114  mm.  The  entoplastron  is  76  mm.  long  and  64  mm.  wide.  The  width  of  the  bridge  is  108 
mm.  The  hinder  lobe  has  a  width  of  108  mm.,  diminishing  in  a  curve  to  a  width  of  96  mm. 
at  the  hypoxiphiplastral  sutures. 

Materials  for  the  study  of  the  skull  are  furnisht  by  the  specimen  at  Yale  University, 
bearing  the  number  484  (plate  37,  figs.  11,  12,  13),  and  by  number  5967  of  the  American 
Museum  of  Natural  History  (plate  38,  fig.  10).  Each  of  these  skulls  is  accompanied  by  its 
shell.  There  appear  to  be  no  specific  differences  between  them.  The  Yale  skull  is  nearly 
complete,  the  only  portions  missing  being  the  roof  of  the  orbits  and  of  the  nasal  cavities. 
The  American  Museum  specimen  supplies  the  parts  missing  in  the  Yale  skull;  but  it  is 
defective  in  many  respects.  That  at  Yale  furnishes  the  description  here  given,  unless  other- 
wise specified. 

Relatively  to  the  size  of  the  shell  the  skull  is  small.  It  is  broad  behind  and  tapers  forward 
to  a  rather  narrow  snout.  The  length,  from  the  snout  to  the  occipital  condyle,  is  67  mm.;  to 
the  extremity  of  the  supraoccipital  spine,  88  mm.  The  greatest  width,  taken  at  the  upper 
borders  of  the  tympanic  cavities,  is  58  mm.  The  temporal  region  is  not  rooft  over,  and  there 
is  no  parieto-squamosal  arch.  The  postorbital  arch  is  slightly  more  than  7  mm.  wide.  The 
zygomatic  bar  is  deeply  excavated  on  its  lower  border,  and  is  10  mm.  wide.  At  the  hinder 
border  of  the  orbit,  where  the  maxilla  joins  the  jugal,  the  former  bone  is  only  5  mm.  wide. 
The  interorbital  space,  as  shown  by  the  American  Museum  specimen,  has  a  width  of  23  mm. 
The  orbits  are  placed  well  forward.  The  antero-posterior  diameter  of  each  was  about  20  mm.; 
the  perpendicular,  17  mm.,  the  latter  dimension  being  furnisht  by  the  American  Museum 
specimen.  This  individual  also  shows  that  the  nares  had  a  perpendicular  diameter  of  1 1  mm., 
a  transverse  diameter  of  16  mm.  The  upper  jaw  is  convex  on  its  lower  border,  rising  in  front 
so  as  to  form  a  median  notch.  This  upper  jaw,  as  shown  especially  by  the  American  Museum 
specimen,  has  a  sharp  cutting-edge,  but  no  masticatory  surface.  This  appears  to  be  an  indi- 
cation that  this  animal  was  not  accustomed  to  crush  shells,  or  other  hard  substances,  but  to 
live  on  more  active  prey. 

The  tympanic  cavity  has  the  longest  diameter  directed  upward  and  slightly  backward; 
its  outer  rim  is  thick  and  heavy.  The  posterior  wall  is  open,  forming  a  notch  for  the  passage 
of  the  stapedial  rod.  The  sutures  between  the  bones  of  the  skull  are  close  and  some  are  to  be 
traced  only  with  difficulty.  There  seem  to  have  been  no  nasals.  As  shown  in  the  skull 
belonging  to  the  American  Museum,  the  prefrontals  run  backward  over  the  orbits  and  join 
the  postfrontals,  excluding  the  frontals  from  the  boundary  of  the  orbit.  From  the  individual 
just  mentioned  the  postfrontals  are  missing,  but  the  sutural  borders  of  the  frontals  and  of  the 
parietals  articulating  with  the  postfrontals  are  well  preserved.  The  jugal  is  a  bone  of  con- 
siderable length,  and  it  forms  a  large  part  of  the  lower  border  of  the  orbit. 
18 


274 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


The  choanx  are  far  forward.  The  roof  of  the  mouth  in  front  is  vaulted,  not  greatly  unlike 
that  of  a  Testudo.  The  vomer  apparently  extended  between  the  palatines  to  the  pterygoids 
or  very  close  to  them.  The  distance  across  the  palatines,  at  their  hinder  ends,  is  20  mm. 
The  distance  across  the  constricted  portion  of  the  pterygoids  is  13  mm.  There  are  posterior 
palatine  foramina.  The  lower  jaw,  as  shown  by  the  American  Museum  specimen,  had  a 
single  sharp  cutting-edge,  which  workt  against  that  of  the  upper  jaw.  The  lower  jaw  appears 
to  have  formed  a  beak  in  front.  The  symphysis  is  short,  about  \z  mm.  in  length.  The  jaw  is 
20  mm.  high  at  the  coronoid  region. 

The  right  humerus  is  present  in  the  Yale  specimen,  and  complete  except  that  the  radial 
tuberosity  is  broken  off.  The  length  from  the  proximal  surface  of  the  head  to  the  distal  end 
is  83  mm.  The  greatest  diameter  of  the  head  is  21  mm.  The  ulnar  tuberosity  is  as  large  as 
that  of  Chelydra.  The  angle  between  the  two  tuberosities  is  nearly  the  same  as  in  Chelydra. 
The  ectepicondylar  foramen  also  resembles  that  of  the  genus  just  named.  The  distal  articular 
surface  appears  to  have  been  bent  toward  the  palmar  surface  more  than  in  Chelydra.  The  ulna 
is  like  that  oi  Chelydra,  but  is,  relatively  to  the  length  of  the  humerus,  longer  than  in  the  genus 
named.  It  is  likewise  thicker  from  the  dorsal  to  the  palmar  surface.  The  length  is  55  mm.; 
the  least  breadth,  8  mm.  The  distal  end  is  19  mm.  wide.  The  dorsal  surface  is  strongly 
markt  by  ridges  for  the  attachment  of  muscles.  About  two-thirds  of  the  radius  is  preserved. 
Some  portions  of  the  hinder  limbs  are  preserved,  wholly  or  partly;  but  they  have  not  been 
completely  removed  from  the  matrix.  The  right  astragalo-calcaneum  was  found  in  the  right 
axillary  notch.    It  resembles  that  of  Chelydra,  but  has  the  fibulare  co-ossified  with  it. 

The  vertebra  are  represented  by  portions  of  two  cervicals,  but  they  furnish  us  little 
information.     One  lies  against  the  head  of  the  humerus  and  presents  a  cup-shaped  articular 

cavity.  The  centrum  is  19  mm.  wide, 
and  there  is  a  sharp  median  carina  on 
its  lower  surface.  One  complete  toe 
is  present  (fig.  339).  It  was  found  in 
the  right  axillary  notch;  but  from  the 
length  of  the  phalanges  and  the  fact 
that  the  right  astragalo-calcaneum 
was  found  close  to  it,  it  is  concluded 
that  it  is  one  of  the  digits  of  the  hin- 
der limb. 

No.  5934  of  the  American  Muse- 
um furnishes  some  fragments  of  the 
cervical  vertebrae-  One  of  these,  a 
posterior  one,  shows  that  on  the  under 
side  of  the  centrum  there  was  a  sharp 
and  prominent  carina.  The  anterior 
A  posterior  caudal  has  the  centrum 


Figs.  339-341. — Baptemys  wyomingensis.     Limb  bone.s. 

339.  Digit  belonging  to  specimen  of  fig.  338.    Xl. 

340.  Ulna.    Xi.    No.  5934  A.M.N. H. 

341.  Terminal  and  penultimate  phalanges.  X§.  No.  5934  A.  M.  N.  H. 


end  of  the  centrum  has  right  and  left  articular  cavities. 
17  mm.  long.  The  total  height  of  the  centrum  and  the  arches  is  23  mm.  The  centrum  is 
procoelous.  The  ulna  is  represented  by  fig.  340.  It  resembles  that  of  Chelydra,  but  it  is  rela- 
tively broader  and  the  radial  border  is  thicker.  Fig.  341  represents  an  ungual  phalanx  and 
the  one  preceding  it.  A  considerable  portion  of  the  pelvis  is  preserved  (figs.  342,  343).  The 
upper  end  of  the  ilium  is  missing,  but  it  was  probably  not  broadened.  On  its  anterior  border, 
half  the  height  above  the  acetabulum,  is  a  strong  process  directed  outward  and  forward.  The 
pelvis  resembles  that  of  Testudo.  The  ischial  symphysis  is  13  mm.  thick.  There  is  a  long 
antero-lateral  pubic  process.   The  pubic  symphysis  was  more  than  23  mm.  long. 

Dr.  Leidy's  second  specimen,  in  the  U.  S.  National  Museum,  furnishes  the  right  scapula. 
This  is  represented  as  seen  from  behind  and  of  two-thirds  the  natural  size  by  fig.  344.  The 
height  of  the  body  above  the  glenoid  fossa  is  102  mm;  the  proscapular  process  is  54  mm.  long. 

Professor  Cope  described  from  Ham's  Fork,  Wyoming,  a  species  which  received  the  name 
Baena  ponderosa.  The  specimens  are  now  in  the  U.  S.  National  Museum,  at  Washington, 
where  the  writer  has  twice  examined  them.  Cope  states  that  his  figures  are  three-fifths  the 
size  of  nature;  but  the  measurements  show  that  they  are  only  half  that  size.  Cope's  fig.  5 
represents  the  first  and  second  right  peripherals.     The  suture  between  the  two  is  not  well 


DERMATEMYDID^. 


275 


shown  in  the  figure.  His  fig.  4  represents  the  second  left  peripheral.  Fig.  8  is  from  a  portion 
of  the  left  first  costal  and  its  median  notch  fits  accurately  on  the  upper  border  of  the  original  of 
his  fig.  4.  Cope's  fig.  6  is  almost  certainly  that  of  the  right  third  peripheral.  In  the  collection 
there  are  present  the  left  second  and  third  peripherals  of  another  individual.  These  bones  cer- 
tainly do  not  belong  to  any  species  oi  Ba'ena.  They  closely  resemble  those  of  Baptemys  wyo- 
mingensis,  and  in  all  probability  belong  to  that  species. 

Cope's  assignment  of  these  bones  to  Ba'ena  was  determined  by  the  bone  represented  by 
his  fig.  3.    It  is  indeed  very  peculiar.    Fig.  345  represents  a  section.    Cope  regarded  it  as  form- 


FiGS.  342-345. — Baptemys  wyommgensts.     Pelvis,  scapula  and  peripheral. 

342.  Pelvis,  from  left  side.    Xj.    No.  5934  A.  M.  N.  H.     it,  ilium;    hch,  ischium;    pub,  pubis. 

343.  Pelvis  of  individual  of  fig.  341.    Seen  from  below.    Xj.    i7,  ilium;   <jf A,  ischium;  put,  pubis.    The  suture 

between  the  right  and  left  pubes  ran  from  a  point  2  mm.  on  the  left  of  the  leader  from  pub  backward  to 
a  point  2  mm.  on  the  left  of  the  line  of  two  short  dashes. 

344.  Scapula.    X?.    Specimen  in  U.S.N. M. 

345.  Section  of  peripheral  described  by  Cope  as  that  of  Ba'ena  ponderosa.     Xi. 

ing  a  part  of  the  hinder  border  of  the  carapace,  the  scute  seen  on  it  being  the  hindermost 
one.  However,  the  writer  has  found  in  the  collection  another  fragment  which  continues  the 
border  5  or  6  mm.  toward  the  left,  and  on  it  begins  another  marginal  scute.  It  is  the  writer's 
conclusion  that  this  bone  also  belongs  to  Baptemys  and  is  a  malformed  portion  of  the  hinder 
border  of  the  carapace. 

Baptemys  tricarinata  sp.  nov. 

Figs.  346-349. 

Dermatemys ,  CoPE,  Bull.  U.  S.  Geol.  and  Geog.  Surv.  Terrs.,  vi,  1881,  p.  184. 

Remains  belonging  to  2  individuals  of  the  present  species  were  collected  in  the  Wind 
River  deposits,  during  the  summer  of  1905,  by  the  expedition  in  charge  of  Mr.  Walter  Granger, 
of  the  American  Museum  of  Natural  History.  One  of  these,  No.  6109,  was  found  at  the 
mouth  of  Alkali  Creek,  Fremont  County,  Wyoming;  the  other.  No.  61 10,  on  the  divide 
between  Alkali  and  Poison  Creeks.  N0.6109  is  made  the  type  of  the  species.  Both  specimens 
are  considerably  fractured,  neither  of  them  furnishing  a  complete  carapace.  Taken  together, 
however,  the  two  specimens  give  practically  the  whole  structure  of  the  shell.  The  species  is 
distinguisht  from  B.  wyomtngensis  by  the  possession  of  three  dorsal  carinae  and  a  pointed 
hinder  plastral  lobe. 

The  carapace  of  No.  6109  (fig.  346)  has  an  approximate  length  of  460  mm.;  a  width  of 
about  330  mm.  Its  structure  differs  only  in  minor  points  from  that  of  fi.  wyomtngensis.  The 
neurals  are  long  and  narrow.    The  peripherals  differ  little  from  those  of  the  Bridger  species, 


276 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


except  that  they,  like  the  other  bones  of  the  carapace,  appear  to  be  somewhat  thinner.  The 
vertebral  scutes  are  perhaps  relatively  a  little  wider  than  in  B.  wyomingensis.  There  are  3 
broad  dorsal  carinje — a  median  and  two  lateral.  The  median  may  be  traced  farther  forward 
than  in  B.  wyomingensis,  as  far  forward  as  the  front  of  the  third  neural.  The  lateral  carinx 
run   just  outside  of  the  vertebral  scutes.     They  are  of  moderate  height  posteriorly;    on  the 


Figs.  346  and  347. — Baptemys  tricarinata.     Carapace  and  plastron  of  type.      Xj. 

346.  Portion  of  carapace,    c.  p.  i,  first  costal  plate;   n.  i,  «.8,  first  and  eighth  neurals. 

347.  Plastron  and  portion  of  carapace. 

anterior  half  of  the  carapace  they  may  be  traced  to  the  first  costal;   but  on  the  three  anterior 
costals  they  form  very  low  ridges. 

Fig.  347  represents  the  plastron.  The  total  length  is  285  mm.  The  anterior  lobe  is  broad, 
rounded,  and  slightly  notcht  in  front.  The  length  is  92  mm.;  the  width  at  the  base,  148  mm. 
The  entoplastron  is  larger  than  in  B.  wyomingensis,  being  65  mm.  long  and  75  mm.  wide.    The 


348. 


349- 


Figs.  348  and  349. — Baptemys  tricarinata.     Plastron  and  humerus  of  type.      X^. 
348.  Anterior  lobe  of  plastron.  349.  Right  humerus. 

bridge  is  93  mm.  wide,  relatively  narrower  than  in  the  Bridger  species.     The  hinder  lobe  is 
105  mm.  long  and  1 1 1  mm.  wide  at  the  base.    The  sides  converge  backward  to  a  point. 

The  scutal  areas  are  represented  in  fig.  347.  No  gulars  are  markt  out;  but  there  is  a  notch 
in  the  border  of  the  epiplastron,  as  if  for  the  crossing  of  the  gulo-humeral  sulcus.  There  are 
on  each  bridge  3  inframarginals  like  those  of  most  specimens  of  B.  wyomingensis. 


DERMATEMYDID^. 


277 


No.  61 10  has  been  a  slightly  smaller  individual.  Fig.  348  represents  the  front  lobe  of  the 
plastron.  It  is  somewhat  more  pointed  in  front  than  that  of  the  type.  What  is  most  interesting 
is  the  presence  of  portions  of  the  gulo-humeral  sulci.  The  extent  and  position  of  these  are  shown 
in  the  figure.  The  presence  of  these  indicates  that  there  has  occurred  in  this  genus  a  coales- 
cence of  the  gulars  and  the  humerals. 

Fig.  349  represents  the  right  humerus  seen  from  the  dorsal  surface.  The  general  form  is 
that  of  the  humerus  oi  Chelydra. 

Baptemys  iluviatilis  sp.  nov. 

Plate  42,  figs.  I,  2;    teit-figs.  350,  351. 

This  species  is  based  on  a  chelonite  which  was  presented  to  the  American  Museum  of 
Natural  History  by  Mr.  Sidney  Dillon,  of  New  York  City,  in  1879.  It  is  said  to  have  been 
obtained  by  him  in  Colorado,  but  there  is  no  record  of  the  exact  locality,  nor  of  the  formation 


35°- 


Figs.  350  and  351. — Baptemys  fluviatilis.     Carapace  and  plastron  of  type.      X\. 
350.  Carapace.    Restored  costal  and  vertebral  scutes  indicated  by  interrupted  dotted  bands.  351.  Plastron. 

from  which  it  was  derived.  The  specimen  probably  belongs  to  the  Bridger  formation  and 
there  may  be  some  error  regarding  the  region. 

The  specimen  consists  of  a  mass  of  gray  sandstone,  broken  into  two  pieces,  which  bears 
considerable  portions  of  the  carapace  and  impressions  of  other  portions  and  a  fragment  of  the 
plastron,  together  with  an  impression  of  the  inner  surface  of  practically  the  whole  plastron. 
While  we  must  regret  the  absence  of  many  parts  which  might  evidently  have  been  preserved, 
there  is  enough  of  the  shell  present  to  furnish  us  with  the  essentials  of  the  structure. 

This  shell  has  a  length  of  438  mm.  and  a  width  of  312  mm.  The  carapace  (plate  42,  fig.  i; 
text-fig.  350)  forms  a  high  vault  which  rises  from  the  lower  surface  of  the  plastron  about 


278 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


Bone. 


Baptemys 
wyomingensis. 


Length. 


Nuchal 

Neural  i . . 
2. . 
3- 
4- 
S-- 
6.. 

7-. 
8.. 
Suprapygal 

Pygal 


7° 
58 
47 
49 


37 
21 

'S 
»9 
28 


Width. 


160  mm.  On  the  anterior  portion  of  the  carapace  there  is  no  median  carina,  but  one  of  some 
prominence  begins  on  the  sixth  neural  and  continues  to  the  end  of  the  shell.  Just  above  the 
pygal  plate  this  carina  swells  out  into  a  considerable  protuberance.  The  margin  of  the  car- 
apace is  nowhere  reverted,  except  slightly  so  behind  the  posterior  legs.  There  is  a  slight 
notch  in  the  shell  just  over  the  tail.  Whether  or  not  the  edges  of  the  rear  of  the  carapace  were 
to  any  degree  serrated  can  not  be  determined  with  certainty,  but  they  probably  were  not. 
Anteriorly  the  edge  of  the  shell  is  smooth  ;  over  the  neck  the  carapace  somewhat  exca- 
vated; the  plastron  relatively  small.  The  lobes,  especially  the  hinder,  leave  large  spaces 
between  the  upper  and  lower  parts  of  the  shell.    The  bridge  is  narrow  antero-posteriorly. 

The  shell  is  rather  thin  in  the  dorsal  and  costal  regions,  from  4  mm.  to  6  mm.,  but  thickens 
toward  the  margin,  the  last  peripheral  being  about  10  mm.  thick.  The  surface  of  the  carapace 
is  usually  smooth. 

In  the  middle  line  of  the  carapace  we  find,  behind  the  nuchal,  8  neural  plates  and  2  supra- 
pygals  and  the  pygal.  The  first  neural  is  of  elongated  oval  form.  The  others,  from  the  second 
to  the  sixth,  inclusive,  are  elongated  hexagonal,  with  the  broad  end  in  front.  The  following 
table  gives  the  dimensions  of  the  nuchal,  the  neurals,  the  two  suprapygals  and  the  pygal. 
There  are  added  the  dimensions  of  B.  wyomingensis,  reduced  to  millimeters,  from  Leidy. 

The  peripherals  are  high,  the 
first  being  55  mm.;  the  fourth,  62 
mm.;  the  tenth,  at  least  72  mm. 

The  plastron  (plate  42,  fig.  2; 
text-fig.  351)  is  the  most  interesting 
and  instructive  portion  of  the  shell. 
Since  all  but  a  mere  fragment  of  it 
is  peeled  off  the  matrix,  we  must 
depend  on  the  impressions  left  on 
the  rock.  As  to  the  general  form  and 
most  of  the  sutures,  there  can  be  no 
doubt.  Its  length  was  282  mm. 
The  anterior  lobe  was  100  mm. 
long,  138  mm.  wide;  the  posterior 
lobe  79  mm.  long,  112  mm.  wide  at 
the  base.  No  trace  is  found  of  the 
hyohypoplastral  suture;  212  mm. 
behind  the  front  end  of  the  plastron 
is  seen  the  very  plain  impression  of  the  hypoxiphiplastral  suture.  It  runs  outward  to  near 
the  border  of  the  plastron,  then  outward  and  forward,  and  finally  turns  abruptly  backward  to 
the  border.  We  must,  however,  remember  that  we  are  viewing  the  upper  surface  of  the  plastron, 
and  that  these  angulations  represent  processes  of  the  bones.  The  xiphiplastrals  had  a  length 
of  72  mm.  and  a  width  of  100  mm.  in  front. 

There  are  very  distinct  impressions  of  the  suture  of  the  entoplastron  and  of  the  epiplastra. 
The  former  was,  on  its  upper  surface,  approximately  circular,  with  a  median  lobe  in  front  and 
a  narrow  prolongation  behind.  Its  length  was  75  mm.,  the  width,  55  mm.  The  hypoplastra 
have  a  length  of  45  mm.  along  the  midline. 

The  sulci  are  broad,  but  often  extremely  obscure;  especially  those  which  separate  the 
vertebral  scutes  from  the  costals.  The  marginal  sulci  are  usually  sufficiently  distinct.  The 
transverse  sulci  of  the  vertebrals  may  be  made  out  satisfactorily.  As  to  the  width  of  the  ver- 
tebrals,  the  drawing  indicates  the  position  of  the  lateral  sulci  as  well  as  the  faint  indications 
will  permit.  The  marginal  scutes  did  not  rise  on  the  sides  as  high  as  the  peripheral  bones. 
There  appear  to  have  been  axillary  and  inguinal  scutes.  In  B.  wyomingensis  there  is  a  com- 
plete row  of  inframarginals. 

This  species  differs  in  various  particulars  from  B.  wyomingensis.  Some  differences  appear 
in  the  hinder  neurals.  There  are  in  B.  fluviatilis  two  suprapygals;  in  B.  wyomingensis, 
three.  It  will  be  observed  from  the  measurements  that  the  hindermost  suprapygal  is  nearly 
three  times  as  wide  as  that  of  fi.  wyomingensis.  There  are  obvious  differences  in  the  plastra, 
that  of  the  present  species  being  more  pointed  behind. 


Baptemys 

fuviatilis. 

Length. 

Width. 

63 

98 

60 

30 

47 

34 

50 

,     3> 

1   '■ 

1      ^' 

38 

34 

22 

3' 

27 

3> 

17 

38 

46 

90 

43 

29 

95 
»7 
30 
30 
30 

34 
36 

IS 
30 
34 


DERMATEMYDID^.  279 

Genus  ANOSTEIRA   Leidy. 

Plastron  articulating  with  the  carapace  by  sutures.  Plastral  bones  9,  the  entoplastron 
lanciform.  Hinder  plastral  lobe  small.  Nuchal  bone  without  costiform  processes.  Ten  pairs 
of  peripherals;  8  pairs  of  costals;  7  neurals.  The  eighth  pair  of  costals  meeting  on  the  mid- 
line.    Epidermal  scutes  developt  at  least  on  the  carapace.    The  vertebrals  greatly  modified. 

Type:  Anostetra  ornata\^^\d.y. 

Dr.  Leidy  did  not  definitely  refer  this  genus  to  any  family,  but  regarded  it,  with  Baena, 
Chisternon,  and  Baptemys,  as  apparently  intermediate  to  the  Pleurodira  and  the  Chelydridae 
(Contrib.  Ext.  Fauna,  etc.,  p.  341).  Cope  (Amer.  Naturalist,  xvi,  1882,  p.  990;  Vert.  Tert. 
Form.  West,  1884,  p.  112)  arranged  the  genus  under  the  Chelydridae;  but  in  the  same  family 
inclose  relation  with  Anosteira  he  included  also  Claudius.  He  arranged  Dermatemys  among 
the  Emydid(C.  Baur  (Ann.  Mag.  Nat.  Hist.,  ser.  ill,  1889,  pp.  58,  276;  Proc.  Acad.  Nat.  Sci. 
Phila.  1891,  p.  420)  favored  placing  it  with  either  Staurotypus  or  Ktnosternon,  according  as 
the  entoplastron  might  or  might  not  be  found  to  be  present.  Mr.  Lydekker  (Cat.  Foss.  Rept., 
Ill,  1889,  p.  143)  places  the  genus  in  the  subfamily  Anosteirinae  under  the  Chelydridae.  Hay 
in  1902  (Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  p.  446)  raised  this  group  to  family  rank,  but  this 
had  already  been  suggested  by  Baur. 

The  nearly  complete  shell  described  below,  presenting  as  it  does  the  entoplastron,  enables 
us  to  refer  the  genus  definitely  to  the  Dermatemydidae.  The  plastron  resembles  closely  that 
oi  Staurotypus  salvinit.  The  presence  of  the  costiform  processes  in  the  living  members  of  the 
family  are  not  regarded  as  being  of  essential  importance. 

There  can  be  hardly  any  doubt  that  Pseudotrionyx  Dollo,  of  the  Middle  Eocene  of  Bel- 
gium, is  a  genus  closely  related  to  Anosteira. 

Anosteira  omata  Leidy. 

Plate  43,  figs.  I,  %;   teit-figs.  352-354. 

Anosteira  omata,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1871,  p.  102;  Ann.  Report  U.  S.  Geo!.  Surv. 
Montana,  etc.,  1871  (1872),  p.  370;  Contrib.  Ext.  Fauna  West.  Terrs.,  1873,  pp.  174,  341,  plate  xvi, 
figs.  1-6. — Hay,  IBibliog.  and  Cat.  Foss.  Vert.  N.  A.  1902,  p.  447;  Bull.  Amer.  Mus.  Nat.  Hist., 
XXII,  1906,  p.  157,  figs.  2,  3. 

Anostira  ornata,  CoPE,  Ann.  Report  U.  S.  Geol.  Surv.  Wyoming,  etc.,  1872  (1873),  p.  621 ;  Amer.  Nat- 
uralist, XVI,  1882,  p.  989,  fig.  7;  Vert.  Tert.  Form.  West,  1884,  p.  128. — Dollo,  Bull.  Mus.  Roy. 
Belgique,  iv,  1886,  p.  93,  pi.  ii,  figs.  7,  8. 

This  beautiful  and  interesting  species  was  based  originally  on  4  individuals,  some  of 
which  had  been  discovered  at  Church  Buttes  and  others  at  Grizzly  Buttes,  Wyoming.  Where 
these  types  now  are  the  writer  does  not  know.  It  is  possible  that  some  of  them  are  included 
under  No.  4062,  of  the  U.  S.  National  Museum.  The  specimen  figured  by  Leidy  was  obtained 
somewhere  in  the  neighborhood  of  Fort  Bridget.  It  is  now  in  the  collection  of  the  Phila- 
delphia Academy.  All  of  his  specimens  appear  to  have  come  from  the  lower  portion  of  level 
B  of  the  Bridget  Eocene.  The  American  Museum  expedition  of  1903  found  fragmentary 
specimens  of  the  species  at  Grizzly  Buttes  and  on  Cottonwood  Creek.  The  expedition  of 
1905  secured  at  Henry's  Fork  a  nearly  complete  shell,  which  is  here  described  and  figured 
(plate  43;  text-figs.  352,  353).    This  comes  from  a  higher  level  than  the  other  known  specimens. 

Leidy's  reconstruction  of  this  species  attributed  to  it  1 1  pairs  of  peripherals.  Dr.  Baur 
was  the  first  to  correct  this  error.  The  complete  specimen  just  mentioned  confirms  Baur's 
statement. 

The  specimen  found  at  Henry's  Fork  belongs  to  the  third  division  of  level  C.  It  has  the 
number  6132,  of  the  American  Museum.  The  specimen  is  slightly  crusht.  The  neurals 
(fig.  352)  are  all  missing,  as  well  as  the  left  front  part  of  the  carapace.  In  form  the  carapace 
is  not  so  much  excavated  in  front  as  is  represented  in  Leidy's  figure.  Other  specimens  of  the 
species  show  as  little  excavation. 

The  total  length  of  the  carapace  (plate  43,  fig.  i;  text-fig.  352)  along  the  median  line  is 
125  mm.  The  width  is  105  mm.  The  nuchal  is  slightly  damaged,  but  its  length  has  been  close 
to  20  mm.  and  the  width  the  same.    The  free  border  is  subacute;  the  thickness  at  the  midline 


28o 


FOSSIL    TURTLES    OK    NORTH    AMERICA. 


is  5  mm.  There  are  eight  pairs  of  costals.  Those  of  the  seventh  pair  join  for  a  short  distance 
behind  the  seventh  neural;  those  of  the  eighth  pair  join  their  full  width.  The  costals  are  thin, 
about  I  mm.  in  thickness.  There  is  a  single  large,  roof-shaped  suprapygal,  whose  length  is 
1 8  mm.  and  whose  width  is  20  mm.  The  pygal  has  a  height  of  15  mm.  and  a  width  of  23  mm. 
The  anterior  peripherals  are  about  12  mm.  high,  at  right  angles  with  the  free  border.  Behind 
the  fifth  this  dimension  increases  until  in  the  ninth  it  is  20  mm.  The  fourth  and  fifth  are  in 
contact  with  the  hyoplastron;  the  fifth,  sixth  and  seventh,  with  the  hypoplastron.  Fig.  354 
represents  the  anterior  ends  of  the, sixth,  seventh  and  eighth.  The  free  border  of  those  in 
front  of  the  bridge  is  subacute;  that  of  those  behind  the  bridge,  thin  and  acute.  The  lower 
face  of  the  anterior  peripherals  is  smooth,  while  that  of  the  posterior  is  sculptured.  The 
latter  peripherals  have  a  third,  or  inner  face.  This  looks  toward  the  interior  of  the  shell  and 
is  concave. 

The  carapace  is  exquisitely  sculptured,  the  costals  differently  from  the  peripherals.    The 
costals  are  crost,  parallel  with  the  axis  of  the  animal,  by  low  undulating  ridges,  most  distinct 


Figs.  352  and  353. — Anosteira  ornata.     Carapace  and  plastron.     X§.     No.  6132  A.  M.N.  H. 

35Z.  Carapace. 

353.  Plastron.    «nr,  entoplastron;  ?/>/,  epiplastron;   /r)'o,  hyoplastron;   Av^o,  hypoplastron;  .r/^/r,  xiphiplastron. 

on  the  distal  ends.  The  nuchal  and  the  peripherals  are  ornamented  by  sharper  ridges  and 
pustular  elevations.  In  general,  the  ridges  and  the  rows  of  pustules  on  the  proximal  half  of 
each  of  these  bones  run  parallel  with  the  costal  border.  Those  on  the  distal  half  radiate  from 
a  focus  placed  some  distance  away  from  the  free  border.  On  the  lower  faces  of  the  six  hinder- 
most  peripherals  of  each  side  the  radiations  extend  to  the  proximal  borders. 

The  epidermal  sulci  are  narrow  and  delicately  imprest,  but  most  of  them  may  be  traced. 
On  the  nuchal  and  the  four  anterior  peripherals  the  intermarginal  sulci  can  not  be  seen, 
owing  to  the  sculpture.  On  the  other  peripherals  the  ascending  sulci  are  easily  followed, 
but  the  costo-marginal  sulci  are  not  visible.  From  this  and  other  specimens  it  becomes  quite 
certain  that  they  ran  along  the  upper  borders  of  the  peripherals,  just  below  the  costo-peripheral 
sutures.  On  the  pygal  a  median  sulcus  ascended  about  half  the  height  of  the  bone,  then 
divided  and  sent  a  right  and  left  into  the  costo-marginal  sulci.  The  vertebral  scutes  appear  to 
have  been  remarkably  modified.  The  first  has  a  width  of  18  mm.  in  front.  We  have  a  right 
to  look  for  a  transverse  sulcus  crossing  this  region  on  the  proximal  ends  of  the  first  costals  and 
the  first  neural;    but  there  is  no  trace  of  it.     Instead  of  this,  we  find  that  the  sulcus  which 


^ 


DERMATEMYDID^.  281 

usually  crosses  on  the  proximal  ends  of"  the  third  costals  and  the  third  neural  starts,  as  usual, 
on  the  third  costals,  but  is  carried  forward  so  as  to  cross  on  the  first  neural.  This  sulcus  in 
the  specimen  is  very  distinct;  besides  this,  it  has  been  observed  on  another  specimen. 
In  the  median  line,  on  the  front  of  the  first  vertebral,  is  seen  a  distinct  sulcus  which  runs  back- 
ward to  the  hinder  border  of  the  nuchal  bone.  Whether  or  not  it  extended  further  can  not  be 
determined.  Probably  it  attained  to  the  transverse  sulcus  on  the  first  neural.  Apparently 
the  only  explanation  of  this  condition  is  to  suppose  that  the  first  and  second  normal  vertebrals 
have  coalesct;  that  the  sulcus  between  the  second  and  the  third  has  been  carried  forward  to 
the  first  neural  and  even  to  the  nucho-vertebral  sulcus;  thus  dividing  the  united  first  and 
second  vertebrals  into  right  and  left  halves. 

It  seems  probable  that  the  third  and  the  fourth  vertebrals  have  coalesct;  for  no  sulcus 
crosses  the  proximal  ends  of  the  fifth  costals  and  the  fifth  neural.  The  vertebral  occupying 
the  area  of  the  fifth  in  other  turtles  has  a  length  of  37  mm.  and  a  width  of  about  30  mm.  As 
an  individual  peculiarity,  the  fourth  costal  scute  of  the  left  side  is  divided  by  a  sulcus  which 
descends  on  the  seventh  costal  bone. 

Fortunately  the  present  specimen  furnishes  the  epiplastra  and  the  entoplastron,  elements 
not  observed  before  (plate  43,  fig.  I ;  text-fig.  353).    The  epiplastra  are  37  mm.  long;  the  width 

is  13.5  mm.  at  the  middle  of  the  length.  They  narrow  ante- 
riorly. The  entoplastron  is  19  mm.  long,  pointed  in  front,  14 
mm.  wide  behind.  These  parts  resemble  considerably  those 
of  Staurotypus  salvtnii  (Boulenger's  Chelonia,  p.  31,  fig.  10) 
but  the  entoplastron  is  more  pointed  in  the  fossil  species  and 
Fig.  sS'^.-Anosteirn  nrnnfa.  Ante-  "^^  epiplastra  are  not  so  prolonged  at  their  hinder  outer 
rior    ends    of   three    peripherals,     angles. 

No.  61 52  A.  M.  N.  H.  The  whole  length  of  the  plastron  is  86  mm.    The  bridges 

have  a  minimum  width  of  15  mm.    It  joins  the  peripherals 

;r,  sixth  peripheral:   y,  seventh:   2,  eiehth.       1  t^,        11  1  j 

>^    '^       '  ■"  >    '    6  [jy  coarse   sutures.      1  he   hyoplastron  is  only  4  mm.  wide 

on  the  bridge.  Its  greatest  fore-and-aft  breadth  is  1 1  mm.  The  fore-and-aft  extent  of  the 
hypoplastra  is  21  mm.;    that  of  the  xiphiplastra,  27  mm. 

The  bones  of  the  plastron  are  markt  by  fine  ridges  and  intervening  grooves.  On  the 
epiplastra  these  radiate  from  a  point  near  the  inner  border,  near  the  hinder  end.  On  the 
bridge  the  sculpture  is  transverse  to  the  length  of  the  body. 

Neither  on  this  specimen  nor  on  any  others  has  the  writer  been  able  to  find  evidences  of 
epidermal  scutes  on  the  plastron.  Doubtless  these  were  present,  but  they  were  so  delicate  that 
their  boundaries  have  left  no  impressions  on  the  bones.  Dr.  Baur  could  not  find  the  sulci  on 
the  plastron  of  specimens  at  Yale. 

Cope  has  mentioned  the  finding  of  specimens  of  this  species  on  the  "Upper  Green  River." 
No.  1059  of  the  American  Museum  of  Natural  History  bears  his  label  to  the  effect  that  it  was 
found  on  Green  River,  at  the  mouth  of  the  Sandy.  The  strata  here  belong  to  the  lowest  level, 
A,  of  the  Bridger.  These  have  furnisht  also  Amyda  cerjuo.  Cope's  specimen  is  somewhat 
differently  sculptured  from  the  specimens  from  a  higher  level,  the  pustules  predominating 
over  the  ridges,  on  the  peripherals.     It  is,  however,  probably  not  a  distinct  species. 

The  evidence  at  hand  shows  that  this  species  ranges  from  the  lowest  level  of  the  Bridger 
beds  to  the  top  of  that  known  as  C. 

Anosteira  radulina  Cope. 

Anosttra  radulina.  Cope,  Palaeont.  Bull.  No.  9,  1872,  p.  555;   Proc.  Amer.  Philos.  Soc,  xii,  1872,  p. 555; 

Ann.  Report  U.  S.  Geol.  Surv.  Montana,  etc.,  1872  (1873),  p.  620;  Vert.  Tert.  Form.  West,  1884, 

p.  128,  plate  xviii,  figs.  18,  19. 
Anosteira  rai/w/a^a,  Baur,  Ann.  Mag.  Nat.  Hist.  (6),  III,  1889,  p.  273. 
Anostira  radiolata,  hyuEKKEK,  Cat.  Foss.  Rept.,  in,  1889,  p.  144. 
Anosteira  radulina.  Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  447. 

This  species  was  described  by  Cope  from  two  peripheral  bones,  one  from  in  front  of  the 
bridge,  the  other  from  behind  it.  These  are  now  in  the  U.  S.  National  Museum  and  have  the 
number  4096.  They  were  found  in  the  Bridger  Eocene  near  Ham's  Fork,  Wyoming,  there- 
fore in  the  lowest  division.  A,  of  the  formation.    The  individual  that  furnisht  these  bones  was 


282  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

estimated  by  Cope  to  have  been  about  twice  the  size  of  the  specimens  of  A.  ornata  that  had 
then  been  found.  He  concluded  that  it  belonged  to  a  distinct  species  for  the  reason  that  the 
sculpture  had  not  increast  in  coarseness  corresponding  to  the  increase  in  size  of  the  animal. 
This,  however,  is  not  a  sufficient  reason.  Since  the  bones  increase  in  size  by  additions  to  their 
borders,  the  lines  and  pits  of  the  sculpture  once  formed  will  not  change  in  coarseness.  A  better 
reason  for  regarding  the  bones  as  those  of  a  species  different  from  A.  ornata  is  to  be  found  in 
their  form.  The  anterior  peripheral,  the  first  of  the  left  side  (Cope's  fig.  18),  has  the  form  of  a 
rhomboid,  quite  different  from  that  of  any  anterior  peripheral  oi  A.  ornata.  The  lower  side  of 
Cope's  figure  is  that  of  the  free  border  of  the  bone.  The  thickness  of  the  bone  is  7  mm.  The 
hinder  peripheral  appears  to  be  the  ninth  or  tenth.  It  is  7  mm.  thick  and  its  free  edge  is  obtuse. 
In  A.  ornata,  on  the  contrary,  it  is  acute. 

The  length  of  the  anterior  peripheral,  along  the  free  edge,  is  25  mm.;  its  height  is  28  mm. 
Both  these  dimensions  in  the  hinder  peripheral  are  25  mm.  The  sculpture  of  the  anterior  bone 
is  stated  to  consist  of  closely  packt  vermicular  ridges  which  run  out  flat  on  the  posterior  and 
upper  borders.  In  the  posterior  the  ornamentation  consists  of  closely  placed  minute  tubercles 
over  the  whole  surface,  these  being  more  or  less  confluent  on  the  posterior  and  upper  borders. 

Mr.  R.  Lydekker  has  described  and  figured  a  species  called  Anostetra  anglica,  from  the 
Lower  Oligocene  of  Hordwell,  England  (Cat.  Foss.  Rept.,  iii,  p.  143,  figs.  34,  35).  Dr.  G. 
Baur  (Ann.  Mag.  Nat.  Hist.,  in,  1889,  p.  273)  has  stated  that  this  can  not  be  distinguisht  from 
Cope's  A .  radulina.  A  glance  at  the  figures  of  the  two  forms  shows  that  they  can  not  be 
identical,  the  sculpture  of  the  English  species  being  far  coarser.  In  A.  ornata  the  suture 
between  the  hypoplastron  and  the  xiphiplastron,  in  crossing  from  the  free  border  to  the  mid- 
line, runs  first  forward,  then  backward,  then  forward  again.  In  the  English  species  it  runs 
obliquely,  but  directly,  inward  and  forward.  It  is  not  probable  that  two  species  of  the  same 
genus  would  be  so  different. 

Genus  XENOCHELYS  Hay. 

Characters  drawn  from  the  type  and  only  known  specimen.  Neurals  6,  the  4  anterior 
having  the  narrow  end  directed  forward.  Only  7  pairs  of  costals;  those  of  the  sixth  and 
seventh  pairs  meeting  at  the  midline.  Ten  pairs  of  peripheral  bones,  and  11  pairs  of  marginal 
scutes;  the  nuchal  scute  very  small.  Plastron  joined  to  the  carapace  without  buttresses. 
Bridge  narrow.    Only  5  pairs  of  plastral  scutes.    Two  inframarginals  on  each  bridge. 

Type:     Xenochelys  jormosa  Hay. 

This  genus  differs  from  Dermatemys  in  having  no  axillary  or  inguinal  buttresses;  5, 
instead  of  6,  pairs  of  plastral  scutes;  and  in  the  form  of  the  anterior  neurals.  In  the  reduced 
number  of  peripheral  bones  and  marginal  and  plastral  scutes  it  resembles  Staurotypus.  In  the 
latter  genus,  too,  3  of  the  anterior  neurals  have  the  narrower  end  directed  forward.  The 
width  of  the  bridge  of  Xenochelys  is  intermediate  between  that  of  Dermatemys  and  that  of 
Staurotypus.  The  two  genera  just  mentioned,  as  well  as  Claudius,  the  nearest  living  relatives 
of  Xenochelys,  are  inhabitants  of  Central  America. 

Xenochelys  formosa  Hay. 
Text-figs.  355,  356. 
Xenochelys  jormosa.  Hay,  Bull.  Amer.  Mus.  Nat.  Hist.,  xxii,  1906,  p.  29,  figs.  2,  3. 

Of  this  species  there  is  at  present  known  only  the  specimen  which  serves  as  the  type.  This 
was  discovered  in  the  year  1904,  at  Quinn  Draw,  Washington  County,  South  Dakota,  by  Mr. 
Albert  Thomson,  of  the  American  Museum  of  Natural  History.  The  deposits  in  which  it  was 
found  belong  to  the  lower  division  of  the  Titanotherium  beds  of  the  White  River  Oligocene. 
The  specimen  consists  almost  wholly  of  the  shell,  and  this  is  somewhat  crusht.  The  plastron 
is  driven  upward  into  the  carapace,  and  a  small  portion  of  the  left  margin  of  the  carapace  is 
wanting.    The  whole  structure  of  the  shell  can  nevertheless  be  determined. 

The  length  of  the  carapace  (fig.  355),  measured  in  a  straight  line,  is  200  mm.;  the  great- 
est width  129  mm.  The  shell  is  therefore  slightly  narrower  proportionally  than  that  of 
Dermatemys  mawii.    The  height  was  moderate.    A  low  rounded  carina  is  found  on  the  nuchal 


DERMATEMYDID^. 


283 


and  another  on  the  hinder  end  of  the  carapace.  There  are  slight  traces  of  a  lateral  carina  on 
each  side,  along  the  outer  borders  of  the  vertebral  scutes.  In  outline  the  carapace  is  slightly 
excavated  in  front  and  notcht  behind.     The  borders  behind  the  inguinal  notches  were  very 

slightly  flared  upwards.  The  nuchal  bone  is  well  developt,  hav- 
ing a  length  and  breadth  each  of  38  mm.  There  are  no  costiform 
processes.  Of  the  6  neurals  the  anterior  4  are  hexagonal,  with 
the  narrower  end  directed  forward,  a  somewhat  unusual  thing 
among  both  Cryptodire  and  Pleurodire  turtles;  nevertheless 
occurring,  according  to  Dr.  Boulenger's  figures,  in  the  case  of  some 
of  the  neurals  of  Staurotypus,  Kinosternon,  Cyclemys,  Geomyda, 
and  Cyclemys.  The  sixth  neural  of  our  species  is  quadrate,  the 
seventh  is  triangular.  The  table  gives  the  dimensions  of  the 
neurals. 

Behind  the  costals  of  the  seventh  pair  there  is  a  single  suprapygal,  22  mm.  long  and  38  mm. 
wide.  This  is  succeeded  by  the  notcht  pygal,  which  has  a  length  of  23  mm.  and  a  width  of 
28  mm. 


Neural. 

Length. 

Width. 

I 

15 

■5 

2 

ig 

16 

3 

18 

16 

4 

16 

■3 

5 

IS 

10 

t> 

g 

II 

355- 


Figs.  355  and  356. — Xenochelys  formosa.    Carapace  and  plastron  of  type.     xj. 

355.  Carapace. 

356.  Plastron,    an,  anal  scute;    ent,  entoplastron;    epi,  epiplastron;  fern,  femoral  scute; 

g,  supposed  gular  scute;    hum,  supposed  humeral  scute. 

As  already  stated,  there  are  only  7  pairs  of  costal  plates,  of  which  the  two  hindermost 
pairs  reach  the  midline  of  the  shell.  The  anterior  pair  is  well  developt,  having  an  antero- 
posterior width  of  35  mm.    The  costals  are  about  3  mm.  in  thickness. 

The  peripheral  bones  are  relatively  large,  and  there  are  only  10  of  them  on  each  side.  The 
second  measures  26  mm.  from  the  free  border  to  the  union  with  the  costal  plate;  the  third, 
35  mm.  The  free  borders  of  the  anterior  and  posterior  peripherals  are  acute.  They  attain 
a  maximum  thickness  of  about  9  mm.  The  sulci  bounding  the  epidermal  scutes  are  moderately 
imprest.    There  is  a  very  small  nuchal  scute.    The  vertebral  scutes  have  a  width  each  of  about 


284  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

35  mm.  The  first  has  a  length  of  45  mm.  In  form  the  vertebrals  resemble  those  oi Staurotypus 
salvtnii.  Along  the  hinder  ends  of  each  of  the  lateral  borders  of  the  three  anterior  vertebrals 
there  is  a  very  deeply  imprest  groove.  In  the  case  of  the  first  and  second  vertebrals  these 
grooves  extend  backward  on  that  neural  bone  which  is  crost  by  the  hinder  border  of  each  ver- 
tebral respectively.  The  grooves  along  the  third  vertebral  scute  run  backwards  on  the  prox- 
imal ends  of  the  costals  of  the  fifth  pair. 

The  marginal  scutes  rise  relatively  little  above  the  free  borders  of  the  shell,  the  second 
having  a  fore-and-aft  extent  of  only  13  mm.;  the  tenth,  of  only  15  mm.  The  costal  scutes  are 
therefore  relatively  broad. 

The  plastron  (fig.  356)  has  a  total  length  of  163  mm.  Where  narrowest,  the  bridge  has  a 
width  of  only  43  mm.  The  axillary  and  inguinal  notches  are  very  narrow.  The  plastron  was 
united  with  the  carapace  by  a  close  suture,  but  there  are  no  buttresses  rising  from  the  plastron. 
The  anterior  lobe  has  a  length  of  52  mm.  and  a  width  of  80  mm.  at  the  base.  It  is  broadly 
rounded  in  front  and  somewhat  repand.  The  border  is  acute.  The  entoplastron  is  broadly 
oval,  29  mm.  long  and  27  mm.  wide.  The  hinder  lobe  has  a  length  of  75  mm.,  and  a  basal 
width  of  62  mm.,  and  is  deeply  notcht  behind.  The  free  border  is  acute,  but  the  thickness 
increases  above,  so  that  where  the  soft  skin  began  the  thickness  was  6  mm.  In  the  middle  of 
the  upper  surface  of  each  xiphiplastron  there  is  a  rather  deep,  smooth  impression,  which  was 
probably  for  the  lateral  process  of  the  pubis. 

According  to  Rutimeyer  (Denkschr.  schweiz.  naturf.  Gesellsch.,  xxv,  1873,  p.  152) 
Dermatemys  mawii  possesses  on  each  xiphiplastron  a  depression  (Bandgrube)  for  the  insertion 
of  the  lateral  process  of  the  pubis. 

The  antero-posterior  extent  of  the  epiplastra  is  35  mm.;  that  of  the  hyoplastra,  41  mm.; 
that  of  the  hypoplastra,  30  mm.;  that  of  the  xiphiplastra,  57  mm. 

Besides  the  inframarginal  scutes,  there  are  only  5  pairs  on  the  plastron  of  this  species. 
Of  the  inframarginals  there  are  2  on  each  bridge — a  small  anterior  and  a  large  posterior. 

It  is  diflScult  to  interpret  the  anterior  plastral  scutes.  Posteriorly  we  find  anals  and 
femorals,  in  the  usual  positions.  In  front  of  the  sulcus  bounding  the  latter  anteriorly  there 
is  not  a  trace  of  a  transverse  sulcus  until  we  reach  the  anterior  end  of  the  entoplastron.  Occu- 
pying the  front  of  the  anterior  lobe  are  2  pairs  of  scutes,  which  look  like  intergulars  and  gulars; 
altho  it  is  not  certain  that  the  former  are  not  consolidated  into  a  single  scute.  It  is  evident  that 
there  has  occurred  either  a  fusion  of  2  pairs  of  scutes  or  an  extirpation  of  one  pair.  If  the  most 
anterior  pair  are  intergulars,  we  must  account  for  the  absence  of  2  pairs  of  scutes.  In  Der- 
matemys the  humero-pectoral  sulcus  has  moved  forward  to  near  the  anterior  end  of  the  hyo- 
plastron.  In  Adocus  pectoralis  this  sulcus  has  lain  partly  on  the  epiplastron.  It  appears 
probable,  therefore,  that  in  Xenochelys  the  sulcus  named  has  moved  far  forward;  that  is, 
to  the  middle  of  the  epiplastron.  If  this  is  the  case,  we  have  here  gulars  and  humerals,  instead 
of  intergulars  and  gulars.  We  have  then  to  suppose  either  that  the  pectorals  and  the  abdom- 
inals have  fused,  without  a  trace  of  the  sulcus  between  them,  or  that  the  pectorals  have 
extended  backward  so  as  to  suppress  the  abdominals.  In  Testudo  oshorniana  the  pectorals 
have  been  nearly  supprest  by  the  forward  expansion  of  the  abdominals.  The  writer  accepts 
the  view  that  in  Xenochelys  we  have  present  the  gulars,  humerals,  pectorals,  femorals,  and 
anals.  The  pectorals  have  an  antero-posterior  extent  of  68  mm.  at  the  midline;  the  femorals 
a  similar  extent  of  32  mm.;  the  xiphiplastrals,  of  37  mm. 

It  may  be  noted  here  that  the  specimen  of  Dermatemys  mawtt  figured  by  Dr.  Boulenger 
(Catalogue  of  Chelonians,  p.  28)  possesses  only  7  pairs  of  costal  plates.  Amie  Bienz  (Rev. 
Suisse  Zool.  et  Ann.  Mus.  d'Hist.  Nat.  Geneve,  in,  p.  61)  states  that  the  species  has  8  pairs  of 
costals.    The  same  statement  is  made  by  Dr.  Rutimeyer  (loc.  cit.). 

Family  EMYDID.S;  Gray. 

Cryptodire  turtles  distinguisht  by  the  following  characters :  Shell  covered  with  epidermal 
scutes.  Peripherals  articulated  to  costals  by  close  sutures  and  by  gomphosis  of  rib-ends. 
Neurals  in  full  series.  Bridges  broad,  usually  sutured  to  peripherals;  in  rare  cases  ligament- 
ously  attacht.  Plastron  broad,  composed  of  9  bones,  the  mesoplastron  never  present.  No 
intergulars  and  no  inframarginals,  except  axillary  and  inguinal.    Procoracoid  process  forming 


EMYDID^.  285 

a  right  angle  with  the  scapula.  Coracoids  not  expanded  at  the  distal  ends.  Humerus  with  the 
radial  and  ulnar  processes  diverging.  Digits  usually  elongated  and  the  median  ones  furnisht 
with  three  phalanges;  only  in  Terrapene  are  the  median  anterior  digits  reduced  to  2  phalanges. 
Feet  fitted  primarily  for  walking,  but  nearly  always  provided  with  a  web  between  the  toes. 
Skull  without  temporal  roof,  except  the  zygomatic  and  postorbital  arches,  the  former 
occasionally  wanting.     Stapedial  passage  open.     Neck  completely  retractile  within  the  shell. 

In  the  present  work  the  writer,  following  by  conviction  the  example  of  a  large  number  of 
students  of  herpetology,  the  names  of  whom  are  mentioned  by  Louis  Agassiz  in  his  Contri- 
butions to  the  Natural  History  of  the  United  States  (vol.  I,  p.  356),  has  separated  the  true  land- 
tortoises,  the  Testudinidae,  from  the  more  or  less  aquatic  forms  that  are  to  be  known  as  the 
Emydidae.  For  this  course  there  appears  to  be  found  in  the  structures  of  the  two  groups 
abundant  justification.  Furthermore,  the  two  families  have  been  clearly  separated  ever 
since  the  time  of  the  Lower  Eocene. 

Even  as  thus  restricted  the  Emydidae  contain  more  genera  and  species  than  any  other  family 
of  Testudines.  According  to  Mr.  G.  A.  Boulenger's  Catalogue  of  Chelonians,  the  Emy- 
didae, excluding  the  land-tortoises,  embrace  seventeen  genera  and  sixty-four  species;  and 
these  numbers  are  to  be  increast,  rather  than  diminisht.  Probably  no  other  family  displays 
a  greater  range  of  habits.  Some  of  the  species  are  almost  wholly  aquatic,  as  those  of  the 
genera  Chrysemys  and  Graptemys;  others  are  semiaquatic,  as  the  members  of  Emys  and 
Clemmys;  while  still  others,  as  Terrapene,  are  nearly  as  terrestrial  as  the  Testudinidae  them- 
selves. Of  the  aquatic  forms  a  few,  as  the  diamond-back  terrapins  {M alaclemys)  affect  the 
salt  waters  of  the  sea-coasts;  while  the  greater  number  inhabit  fresh-water  lakes  and  streams. 
Most  of  the  species  are  carnivorous  in  their  diet,  but  a  few,  as  the  box-tortoises  (Terrapene) 
subsist  on  vegetation. 

As  regards  their  present-day  distribution,  the  Emydidae  are  found  occupying  portions  of 
all  the  continents  and  the  larger  islands  of  the  warmer  portions  of  the  globe,  except  Australia 
and  the  neighboring  islands  (fig.  13,  page  33).  It  is  evident  that  by  some  ancient  connection 
of  Australia  with  other  lands,  probably  with  Asia,  the  Pleurodires  were  enabled  to  occupy 
that  southern  continent,  as  well  as  New  Guinea;  but  this  connection  was  interrupted  before 
the  Emydidae  and  the  Testudinidae  had  passed  over  that  bridge. 

Altho  the  Emydidas  have  secured  a  foothold  in  the  African  continent,  their  distribution  is 
limited  to  the  northwestern  and  northern  coasts.  Only  2  species  are  known  from  Africa — 
Emys  orbicularis  and  Clemmys  leprosa.  The  first  is  widely  spread  over  Europe  and  south- 
western Asia  and  is  found  in  Algeria.  It  is  within  the  range  of  possibility  that  it  has 
been  introduced  into  Algeria  through  human  agency.  Clemmys  leprosa  is  found  along  the 
southern  Mediterranean  coast,  from  Tunis  to  the  Atlantic,  thence  southward  to  Senegal. 
It  has  evidently  entered  Africa  at  a  late  geological  period  and  has  prest  southward  along 
the  Atlantic  coast  until  it  has  reacht  the  border  of  the  Ethiopian  region.  To  turtles,  as  to 
other  groups  of  animals,  the  Sahara  desert  has  for  a  long  period  stood  as  a  barrier  to  their 
southern  migration. 

It  is  a  fact  difficult,  perhaps  impossible,  of  explanation  at  present,  that  while  the  Emydidae 
are  absent  from  the  Ethiopian  region,  the  Testudinidae,  a  strictly  terrestrial  family,  and  the 
Trionychidae,  wholly  aquatic  in  their  habits,  abound  in  that  great  region.  It  might  seem  that 
where  the  Trionychidx  could  go  the  Emydidae  could  easily  follow.  However,  the  Trionychidae 
are  a  much  older  family  and  might  have  entered  Africa  before  the  Emydidae  had  become 
widely  distributed  and  at  a  time  when  the  connections  of  the  continents  were  greatly  different 
from  those  now  existing.  It  seems  establisht  that  some  of  the  species  of  Trionychidae  have  been 
able  to  adapt  themselves  to  life  in  sea-water,  and  this  ability  may  have  allowed  them  to  work 
their  way  along  sea-coasts  from  one  fresh-water  region  to  another. 

The  Testudinidae,  on  the  other  hand,  are  less  dependent  on  abundance  of  water  for  exist- 
ence than  are  the  Emydidae  and  might  have  made  their  way  across  the  Sahara  or  the  deserts  of 
western  Asia  into  the  Ethiopian  region.  To  the  writer  it  appears  more  probable  that  the  land- 
tortoises  reacht  Africa  from  India  by  a  land  connection,  of  which  the  Seychelles,  Mauritius,  the 
Aldabras,  and  Madagascar  are  remnants  which  within  recent  or  Pleistocene  times  have  been 
inhabited  by  gigantic  Testudinidse. 


286  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

In  the  Pliocene  deposits  of  the  SiwaUk  Hills,  India,  there  have  been  found  five  genera  of 
Emydidae.  Why  these  did  not  effect  an  entrance  into  Africa  in  company  with  the  various 
ruminants,  hog-like  ungulates,  antelopes,  monkeys  and  apes,  is  not  now  to  be  explained. 

We  have  no  certain  evidence  of  the  existence  of  Emydidae  before  the  beginning  of  the 
Tertiary.  Indeed,  not  until  the  Wasatch  epoch  in  America  and  the  epoch  of  the  London  Clay 
in  Europe,  do  we  find  undoubted  Emydidae.  When  they  do  appear  they  are  in  many  respects 
as  advanct  as  are  some  of  the  living  forms.  We  can  not,  therefore,  doubt  that  they  had  a  much 
earlier  beginning  and  we  may  await  with  confidence  the  discovery  of  their  predecessors  in 
Cretaceous  deposits.  The  genus  Gyremys,  found  in  the  Judith  River  beds,  is  provisionally 
assigned  to  the  family. 

As  regards  the  evolution  of  the  family  not  much  can  be  said.  In  the  Eocene  forms  the  shell 
resembles  greatly  that  of  the  modern  genera.  It  is  composed  of  the  same  pieces  and  these  are 
arranged  in  the  same  way.  Most  of  the  forms  from  the  Wasatch  and  the  Bridger  possess 
strongly  developt  axillary  and  inguinal  buttresses,  such  as  we  find  to-day  in  a  number  of 
Asiatic  genera.  There  appear  to  have  been  other  genera  which  did  not  possess  such  buttresses, 
and  from  such  as  these  have  probably  descended  most  modern  forms. 

We  are,  unfortunately,  without  sufficient  materials  to  enable  us  to  determine  the  structure 
of  the  rest  of  the  skeleton.  The  limbs  of  the  Bridger  turtles,  so  far  as  represented,  were  not 
different  from  those  of  living  aquatic  emyds.  Only  a  single  Bridger  emyd  skull  is  known,  and 
this  was  not  associated  with  a  shell.  This  skull  resembles  considerably  that  of  our  genus 
Clemmys,  the  triturating  surfaces  of  the  jaws  being  narrow  and  with  only  a  rudimentary 
longitudinal  ridge.  In  many  modern  genera  of  this  family  the  jaws  have  become  broadened 
and  the  maxillary,  and  sometimes  the  mandibular,  triturating  surfaces  have  developt  one  or 
more  longitudinal  ridges.  The  horny  plates  which  cover  these  surfaces  are  often  rough  with 
processes  that  resemble  and  function  as  teeth.  The  living  genus  Terrapene,  as  befits  its 
terrestrial  mode  of  life,  has  simulated  many  of  the  features  of  Testudo.  The  shell  has  become 
inflated,  the  digits  shortened,  and  the  diet  a  vegetable  one.  Besides  these  modifications,  the 
plastron  has  become  movable  on  the  carapace  and  a  hinge  has  developt  between  the  hyo- 
plastron  and  the  hypoplastron.  Even  in  the  Lower  Oligocene  the  genus  Ptychogaster  had 
developt  somewhat  similar  structures. 

Mr.  G.  A.  Boulenger  (Catalogue  of  Chelonians,  p.  49)  has  exprest  the  opinion  that  the 
genus  Entys  is,  in  many  respects,  the  least  specialized  of  this  family  and  might  be  placed  at  the 
base  of  the  family,  with  two  series  of  genera  culminating,  on  the  one  hand,  in  the  Batagurs 
and,  on  the  other,  in  the  land-tortoises.  The  present  writer  can  not  agree  in  this  opinion.  He 
holds  first  of  all  that  the  land-tortoises  form  a  distinct  family  which  diverged  from  the  Emydidae 
even  as  early  as  the  Cretaceous.  Again,  Entys  displays  a  rather  high  grade  of  differentiation 
in  the  ridged  triturating  surfaces  of  the  jaws,  and  especially  in  the  secondary  loosening  of  the 
articulation  between  the  carapace  and  the  plastron,  and  in  the  formation  of  a  hinge  between 
the  hyoplastron  and  the  hypoplastron.  Such  a  form  as  Clemmys  appears  to  represent  better 
the  simple  emyd  structure.  In  this  the  jaws  are  narrow  and  smooth,  the  plastron  is  immovably 
articulated  with  the  carapace,  there  is  no  hinge  in  the  plastron,  and  the  plastral  buttresses  are 
feeble.  From  such  a  form  there  might  be  produced  the  Batagurs,  with  their  broad  corrugated 
jaws  and  their  powerful  buttresses,  and  Emys  and  Terrapene,  with  their  narrow  jaws,  their 
feeble  buttresses,  and  their  hinged  plastra. 

From  what  forms  the  Emydidae  sprang  we  know  not  as  yet.  We  shall  probably  find  that 
the  limbs  of  the  earliest  Cryptodira  were  not  greatly  different  from  those  of  our  aquatic  Emy- 
didae. The  shells  of  the  family  ancestral  to  the  Emydidae  need  not  have  differed  greatly  from 
that  of  Chrysemys,  for  example;  for  even  the  early  Amphichelydia  have  the  carapace  and  the 
plastron  closely  articulated.  The  buttresses  of  the  ancestors  of  the  early  emyds  were  probably 
little  developt.  The  neck  was  probably  short  and  the  head  not  wholly  retractile  within  the 
shell.  The  skull  was  probably  considerably  like  that  of  Chelydra,  but  with  a  more  completely 
developt  temporal  roof.  Perhaps  the  skull  of  Platysternum  resembles  it  more.  Such  a  family 
would  not  be  greatly  removed  from  the  Thalassemydidae. 

In  a  paper  publisht  in  the  Bulletin  of  the  American  Museum  of  Natural  History,  vol. 
XXI,  p.  167,  the  author  indicated  his  belief  that  the  Emydidae  had  sprung  from  the  Chelydridae. 
He  is  now  inclined  to  the  opinion  that  they  had  their  origin  from  some  of  the  more  primitive 


EMYDID^. 


287 


Dermatemydidae.  The  latter  family  was  abundantly  represented  during  the  Upper  Cretaceous 
and  only  slight  modifications  would  be  required  to  transform  them  into  Emydidae. 

In  Europe  the  earliest  Emydidae  appear  to  be  those  found  in  the  London  Clay,  which 
is  of  about  the  same  age  as  the  American  Wasatch  beds.  Two  species  are  found  there;  and 
these  have  been  referred  by  Mr.  Lydekker  to  Chrysemys,  2l  living  North  American  genus. 
Doubtless  when  the  skulls  shall  have  been  found  these  species  will  have  to  be  relegated  to  some 
other  genus.  In  the  Oligocene  of  Hordwell,  England,  two  species  occur  which  Lydekker 
refers  to  Ocadia,  a  genus  existing  to-day  in  China.  It  resembles  closely  the  genus  Echmatemys, 
but  the  latter  probably  did  not  have  a  longitudinal  ridge  on  the  maxillary  triturating  surface, 
and  the  plastron  is  less  contracted  than  it  is  in  Ocadia.  No  other  species  of  Emydidae  have 
been  discovered  in  England,  so  far  as  known  to  the  writer. 

On  the  continent  of  Europe,  as  recorded  by  Maack  (Palxontographica,  xviii,  1869,  p.  193) 
and  by  Zittel  (Handbuch  der  Palaeontologie,  iii,  p.  537),  many  species  of  Emydidae  have  been 
described  and  the  greater  part  of  them  referred  to  Emys,  Cistudo,  and  Ptychogaster.  Only 
those  called  Cistudo  are  really  members  oi Emys  as  now  understood.  This  genus  thus  appears 
to  extend  back  to  the  Oligocene.  Those  placed  by  Maack  and  Zittel  in  the  genus  Emys  are 
probably  more  closely  related  to  Clemmys  or  Ocadia.  Ptychogaster  is  an  Oligocene  and  Lower 
Miocene  genus,  the  carapace  of  which  resembles  in  many  respects  that  of  Testudo,  while  the 
plastron  is  hinged  like  that  of  Terrapene. 

The  following  table  shows  the  distribution  of  the  North  American  fossil  species  of  the 
Emydidae: 


Terrapene  Carolina,  T.  eurypygia,  T.  marnochi,  Trachemys  bisornata,  T.  petrolei,  T.  truUa, 
Pleistocene.            Equus.               Chrysemys  timida,  Clemmys   insculpta,  Clemmys?   percrassa,  C.  insculpta,    ?Pseudemys 
caelata.                                                                                                                                                      \ 

\       Blanco,        1  Terrapene  putnami,  r  Trachemys  euglypha,T.  sculpta,  T.jarmani,  .'Clemmys  hesperia,  Dei- 

■nf                  '    Rattlesnake,  ,       rochelys  floridana,  Pseudemvs  extincta. 

Pliocene.                    j                                                                                                                                                                       ^ 

and                                                                                                                                                                                   : 

Peace  Creek.                                                                                                                                                                           ! 

Miocene. 

Loup  Fork. 

Trachemys  hilli,  Clemmys  saiea.                                                                                                    ! 

John  Day 

Oligocene. 

White  River 

Graptemys  inornata. 

Uinta. 

Echmatemys  callopyge,  E.  uintensis. 

Eocene. 

Bridger. 

Echmatemys  septaria,  E.  shaughnessiana,  E.  ocyrrhoe,  E.  stevensoniana,  E.  haydeni,  E. 
arethusa,  E.naomi,  E.  cyane,  £.  xgle,  £.  wyomingensis,  E.?  latilabiata,  £.  pusilla,  Palaeo- 
theca  polycypha,  P.  terrestris,  Clemmys  morrisije,  Hybemys  arenaria. 

Wind  River. 

Wasatch. 

Echmatemys  lativertcbralis,  E.  cibollensis,  E.  testudinea,  E .  megaulai,  E.  euthneta. 

Puerco. 

Laramie. 

Upper 

Foi  Hills. 

Judith  River. 

.'Gyremys  spectabilts. 

Key  to  Genera  of  Emydid^. 

A.  Insufficiently  known  genera. 

a'.  Carapace  broad  as  long;   the  outer  surface  sculptured  somewhat  as  in  Trionychidx.  .Gyremys 

a^.  Small  Bridger  species,  with  dorsal  keel  and  thick  bones Palisotheca 

a'.  A  hemispherical  boss  situated  on  each  interperipheral  suture Hybemys 

AA.  Better  known  genera. 

a'.  Axillary  and  inguinal  buttresses  strongly  developt;   the  latter  projecting  well  into 

the  cavity  of  the  shell  and  rising  high  above  the  costo-peripheral  suture Echmatemys 

a^.  Buttresses  rising  but  little  above  the  costo-peripheral  sutures, 
t'.  Plastron  without  either  lateral  or  transverse  hinge. 

c.  Crushing-surface  of  upper  jaw  with  feeble  or  no  longitudinal  ridge. 

(/'.  Humero-pectoral   sulcus    crossing   the   entoplastron    Clemmys 

d^.  Humero-pectoral  sulcus  crossing  behind  the  entoplastron. 


288  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

1.  Shell  smooth;    no  dorsal   keel;    crushing-surface  of  upper  jaw 

with  a  feeble  ridge;    rib-heads  well  developt Ckrysemys 

2.  Surface  of  shell  sculptured;   rib-heads  thread-like Deirochelys 

3.  Shell  smooth  or  wrinkled ;  crushing-surface  of  upper  and  lower 

jaws  broad  and  flat;  palatine  bones  joining  vomer  in  front  of 

choanae Graptemy 

c^.  Crushing-surface  of  upper  jaw  with  a  strong  longitudinal  ridge. 

4.  At   least   a   trace   of  a   dorsal   keel;    carapace  often  sculptured; 

crushing-surface  of  upper  jaw  with  a  denticulated  ridge  highest 

in  front Trachemys 

5.  Crushing-surface  of  upper  jaw   very  broad,  with   a   denticulated 

longitudinal  ridge;   lower  surface  of  lower  jaw  flat Pseudemys 

P.   Plastron  completely  filling  the  opening  of  the  carapace;    furnisht  with  both 

lateral  and  transverse  hinges Terrapene 

Genus  GYREMYS  nov. 

Shell  deprest;  as  broad  as  long,  or  broader;  with  plastron  and  carapace  sculptured  as  in 
the  Trionychidae;  both  furnisht  with  epidermal  scutes,  the  vertebrals  very  broad.  Carapace 
with  a  complete  set  of  peripherals.  Neurals  mostly  hexagonal,  with  the  broader  end  forward. 
Plastron  without  fontanels,  and  joined  to  the  carapace  by  means  of  anterior  and  posterior 
buttresses.    Apparently  no  mesoplastra  present. 

Type:    Gyremys  spectabtlis. 

This  genus  differs  from  Glyptops,  as  represented  by  G.  pUcatulus,  in  the  form  of  the  cara- 
pace, the  width  being  greater  than  the  length,  and  in  the  character  of  the  ornamentation  of  the 
shell.  The  lack  of  mesoplastra,  if  confirmed,  will  be  decisive  in  showing  its  non-relationship 
to  Glyptops.  In  the  latter  genus,  as  well  as  in  Pleurosternon,  the  suture  between  the  hypoplastra 
and  the  xiphiplastra  runs  across  the  plastron  in  a  straight  line  or  is  even  deflected  backward  at 
the  midline,  apparently  a  primitive  character;  while  in  Gyremys  the  suture  is  deflected  forward 
at  the  midline. 

Provisionally  this  genus  is  arranged  with  the  Emydidae.  No  intergulars  or  inframarginals 
have  been  observed,  but  they  may  nevertheless  have  been  present.  It  is  possible  that  the  genus 
belongs  among  the  Dermatemydidae. 

Gyremys  spectabilis  sp.  nov. 
Plate  44,  figs.  I,  2;   text-figs.  357,  358. 

Under  this  name  there  is  here  described  a  remarkable  turtle  which  was  collected  in  1876 
for  Professor  Cope,  by  Messrs.  Sternberg  and  Isaac,  in  the  Judith  River  deposits  of  Montana. 
Apparently  the  remains  were  never  examined  by  Professor  Cope,  and  the  many  fragments 
of  which  it  was  composed  were  put  together  after  it  came  to  the  American  Museum  of  Natural 
History.    The  specimen  bears  the  number  1171. 

The  bones  of  this  turtle  were  originally  thin;  and  as  a  result  of  the  conditions  attending 
fossilization  they  have  been  much  fractured.  Consequently,  it  is  difficult  to  determine  the 
positions  of  some  of  the  sutures  and  scutes,  especially  those  of  the  carapace. 

As  regards  the  parts  remaining,  the  plastron  is  complete;  the  carapace  lacks  the  nuchal 
bone,  the  right  first  peripheral,  the  left  first  costal,  and  several  of  the  left  peripherals. 

The  shell  was  a  remarkably  broad  and  flat  one.  The  total  length  of  the  carapace  (plate  44, 
fig.  i;  text-fig.  357)  was  about  440  mm.;  the  width,  500  mm.  Hence,  the  shell  was  broader 
than  long.  As  restored,  the  height  of  the  carapace  above  the  bottom  of  the  plastron  is  only 
70  mm.    It  was  no  doubt  more  elevated  during  life,  but  probably  not  much. 

The  ornamentation  of  the  shell  consists,  where  distinctly  displayed,  of  low,  short,  irregular 
ridges,  separated  by  grooves  of  the  same  width,  and  occasionally  anastomosing.  There  are 
about  five  ridges  in  10  mm.  The  central  portions  of  the  carapace,  however,  are  nearly  smooth. 
In  most  parts  of  the  shell  the  sculpture  is  so  effaced  that  its  character  can  hardly  be  determined, 
beyond  the  fact  that  it  resembles  that  of  the  Trionychidae. 

However,  the  relationships  of  this  turtle  are  not  with  the  Trionychidae,  but  with  the 
Cryptodira;  for  the  plastron  is  completely  closed  and  the  costals  are  surrounded  by  a  complete 


EMYDIDiE. 


289 


set  of  peripherals.  No  fontanels  occur  anywhere,  except  apparently  a  small  one  on  each  side 
of  the  suprapygal. 

On  account  of  missing  parts,  the  outline  of  the  front  of  the  carapace  can  not  be  determined. 
The  shell  was  broadest  across  the  inguinal  region.  The  hinder  border  shows  a  broad  shallow 
excavation.  An  attempt  has  been  made  to  map  out  the  areas  occupied  by  the  neurals,  costals, 
and  peripherals.  The  position  of  most  of  these  has  been  determined  pretty  satisfactorily.  The 
extent  of  the  peripherals  is  somewhat  conjectural,  as  shown  by  the  interrupted  lines  in  the 
drawing.  Most  of  the  sutures  had  to  be  traced  on  the  inside  of  the  carapace.  As  there  seen, 
the  costals  approach  to  within  45  mm.  of  the  free  border  of  the  carapace. 

So  far  as  can  be  determined,  the  inguinal  buttresses  rest  against  the  fifth  and  sixth  costals. 
The  buttresses  did  not  rise  to  a  great  height.  The  ribs  were  quite  prominent  on  the  under  side 
of  the  costal  plates.  The  rib-heads  were  strongly  developt.  The  tenth  rib  formed  an  abutment 
for  the  upper  end  of  the  ilium. 

The  first  neural  is  missing.  The  second  has  the  front  border  wanting,  but  it  was  about 
48  mm.  long  and  27  mm.  wide.    The  third  is  hexagonal,  46  mm.  long  and  48  mm.  wide.    The 


Figs.  357  and  358. — Gyremys  spectahilis.     Carapace  and  plastron  of  type.      X^. 
357.  Portion  of  carapace.  358.  Plastron. 

limits  of  the  fourth  are  uncertain;  it  may  have  been  wider  than  represented.  The  plotting  of 
the  areas  behind  the  eighth  neurals  and  costals  is  to  some  extent  conjectural.  The  thickness 
of  the  costals  is  from  7  mm.  to  10  mm.;  but  the  ribs  added  something  to  this  in  the  middle  of 
the  breadth. 

The  scutal  areas  are  even  more  difficult  to  determine  than  are  the  bones.  Enough,  how- 
ever, is  determinable  to  prove  that  the  vertebral  scutes  were  very  broad,  the  second  and  the 
third  having  had  a  breadth  of  about  170  mm.  The  boundaries  of  the  fourth  are  conjectural, 
but  probably  not  greatly  different  from  the  drawing.  Toward  the  borders  of  the  carapace  no 
sulci  are  to  be  detected  and  no  attempt  has  been  made  to  represent  them. 

The  plastron  (plate  44,  fig.  2;  text-fig.  358)  is  well  preserved,  altho  the  external  layer  of 
bone  on  its  upper  surface  is  eroded  away.  The  lower  surface  is  in  better  condition,  but  the 
bone  is  much  fractured.  The  total  length  of  the  plastron  is  425  mm.  The  anterior  lobe  is 
broad  and  rounded  in  front;  the  hinder  is  somewhat  wedge-shaped,  with  the  extremity  trun- 

19 


29&  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

cated.  The  anterior  lobe  is  240  mm.  wide  at  the  base  and  118  mm.  long.  There  is  no 
specialized  epiplastral  lip.  The  bones  are  about  10  mm.  thick,  and  the  free  borders  are  sub- 
acute. The  posterior  lobe  is  144  mm.  long  and  205  mm.  wide  at  the  base.  The  lateral  borders 
are  somewhat  convex  in  outline,  and  they  converge  toward  the  rear.  The  latter  is  truncated 
and  about  50  mm.  wide.  The  median  and  the  hinder  portions  of  the  lobe  are  thin,  from  4  mm. 
to  8  mm.  From  the  acute  borders  of  the  hypoplastron  the  bone  thickens  inward  a  distance  of 
30  mm.,  then  grows  thinner. 

The  axillary  and  the  inguinal  buttresses  extend  inward  little  further  than  the  free  borders 
of  their  respective  lobes.  The  entoplastron  is  diamond-shaped,  with  the  posterior  angle 
rounded.  It  is  75  mm.  wide  and  65  mm.  long.  The  hyoplastra  occupy  1 12  mm.  of  the  midline; 
the  hypoplastra  about  no  mm.;  the  xiphiplastra,  100  mm.  A  very  careful  examination  fails 
to  discover  the  presence  of  mesoplastra. 

The  gular  scutes  appear  extraordinarily  large  and  the  shallow  grooves  which  are  taken  to 
represent  them  may  be  deceptive.  No  evidences  are  found  of  the  presence  of  intergulars, 
but  they  may  have  existed.  The  gulars  overlap  the  front  of  the  entoplastron.  The  humero- 
pectoral  sulcus  does  not  cross  any  part  of  the  entoplastron.  The  humerals  extend  along  the 
midline  38  mm.;  the  pectorals,  75  mm.;  the  abdominals,  62  mm.;  the  femorals,  no  mm.; 
the  anals,  40  mm.    It  is  impossible  to  make  any  statement  regarding  the  scutes  of  the  bridges. 

Genus  CLEMMYS  Ritgen. 

Shell  only  moderately  elevated.  Neural  plates  hexagonal,  with  the  broader  ends  forward. 
Usually,  but  not  always,  at  least  some  traces  of  a  dorsal  keel.  Axillary  and  inguinal  buttresses 
feeble,  extending  upward  little,  if  any,  above  the  lower  borders  of  the  costals;  the  inguinal 
articulating  with  the  fifth  costal.  Humero-pectoral  sulcus  crossing  the  entoplastron.  Plastron 
notcht  behind.  Triturating  surfaces  of  the  jaws  narrow,  not  furnisht  with  ridges.  Choanae 
between  the  eyes. 

Type:     Clemmys  punctata  SchoepfF=C  guttata  Schneider. 

At  the  present  day  there  are  about  6  living  species  of  this  genus.  These  inhabit  Europe, 
northwest  Africa,  southwestern  Asia,  China,  Japan,  and  North  America.  Four  of  the  known 
species  occupy  portions  of  North  America,  3  of  them  being  limited  to  the  region  east  of  the 
Mississippi  River,  i  to  the  Pacific  coast.  In  the  present  work  five  fossil  species,  all  based 
unfortunately  on  fragmentary  materials,  are  referred  to  this  genus.  One  of  these,  C.  saxea, 
belongs  to  beds  believed  to  be  Pliocene,  a  second  species,  C.  hesperia,  to  the  Mascall  beds  of 
the  Upper  Miocene;  a  third  species,  C.  morrisicB,  to  the  Bridger  Eocene;  a  fourth  supposed 
species  is  C.  percrassa  Cope  from  the  Pleistocene  cave  near  Port  Kennedy,  Pennsylvania. 
It  seems  probable  that  North  America  is  the  original  home  of  the  genus  and  that  the  Old 
World  has  received  its  stock  from  the  New  World. 

The  descriptions  of  the  species  of  this  genus  are  introduced  at  this  stage  because  it  appears 
to  the  writer  that  the  structure  is  rather  primitive  and  that  from  this  genus  may  have  been 
developt  almost  any  of  the  other  forms  of  the  Emydidx. 

1.  Eocene   species   (Bridger   beds):         ■     ,    ''        "' 

Resembling  C.   muhlenbergi morrisite 

2.  Upper  Miocene  species  (Mascall  beds): 

Resembling  C.  marmorata hesperia 

3.  Pliocene  species  (Rattlesnake  beds): 

Pygal   bone  transversely  convex saxea 

4.  Pleistocene  species: 

'■  Hinder  lobe  greatly  thickened percrassa 

'  '  Hinder  lobe  moderately  thickened insculpta 

Clemmys  morrisiae  sp.  nov. 
Plate  45,  figs.  1-3;   text-figs.  359,  360. 

Of  this  interesting  species  there  were  collected  by  the  American  Museum  expedition  of 
1903,  in  the  western  portion  of  Grizzly  Buttes,  portions  of  4  individuals.    These  now  have  the 


EMYDID^. 


291 


catalog  numbers  6019,  6020,  6024,  and  6029.    The  level  from  which  these  were  obtained  is 
that  known  as  horizon  B.    No.  6029  is  taken  as  the  type  of  the  species. 

The  portions  of  the  skeleton  presented  by  the  specimens  bear  such  close  resemblance  to 
the  corresponding  parts  of  Clemmys  muhlenhergi  that  the  species  is  referred  provisionally  to 
that  genus. 

The  type  furnishes  most  of  the  anterior  lobe  of  the  plastron,  a  portion  of  the  hinder  lobe, 
a  part  of  the  nuchal,  parts  of  the  right  first,  second,  and  third  peripherals,  and  the  whole  free 
border  of  the  left  second  peripheral.  The  nuchal  (fig.  359)  was  about  19  mm.  wide  along  the 
free  border  and  about  32  mm.  wide  at  the  maximum.  The  front  border  is  acute-edged,  but 
the  bone  grows  rapidly  thicker  until,  at  a  distance  of  about  12  mm.  behind  the  free  border  and 
near  its  articulation  with  the  peripheral,  it  is  9  mm.  thick.  On  the  under  side  of  the  bone,  at 
a  distance  of  15  mm.  from  the  free  border,  behind  the  portion  covered  with  horn,  the  thickness 
becomes  suddenly  reduced  to  5  mm.  The  free  edge  of  the  first  peripheral  is  acute  next  the 
nuchal.  The  second  peripheral  has  a  length  of  16.5  mm.  along  the  free  border.  This  is  very 
obtuse,  especially  where  it  joins  the  third  peripheral.  The  greatest  thickness  of  this  peripheral 
is  9  mm.  On  the  under  side,  at  a  distance  of  12  mm.  from  the  free  edge,  the  thickness  is 
abruptly  reduced  to  3  mm.  The  nuchal  scute  is  9 
mm.  wide  posteriorly  and  about  6  mm.  long.  The  first 
marginal  scute  had  a  fore-and-aft  extent,  or  height,  of 
12  mm.  at  the  distal  end.  The  second  marginal  at  its 
distal  end  on  the  second  peripheral  was  narrowed 
down  to  7  mm.  in  height.  The  height  of  the  third 
was  about  10  mm.  at  the  distal  end.  On  the  lower 
side  of  the  nuchal  and  of  the  peripherals  the  horny 
scutes  extended  backward  as  far  as  the  thickened  part 
of  the  bones  continued. 


Figs.  359  and  ■^to.—Chmmys  morrisia.  Portions  of 
carapace  and  plastron  of  type.  X  §.  Known  por- 
tions inclosed  within  solid  lines. 

359.  Restoration  of  front  of  carapace. 

360.  Restoration  of  plastron. 

The  anterior  lobe  of  the  plastron  (plate  45,  fig.  i ;  text-fig.  360)  had  a  width  of  about  65 
mm.  Seen  from  below  (fig.  360),  the  lobe  is  convex  in  every  direction.  The  lip  projects 
extremely  little.  Its  width,  measured  between  the  gulo-humeral  sulci,  is  29  mm.  The  ento- 
plastron  has  a  width  of  25  mm.  Its  length  can  not  be  exactly  determined,  but  it  probably 
little  exceeded  25  mm.  In  form,  so  far  as  preserved,  it  resembles  that  of  C.  muhlenhergi. 
The  gular  scutes  overlap  only  slightly  the  front  of  the  entoplastron.  Their  length  on  the  midline 
is  19  mm.  The  humerals  measure  on  the  midline  14  mm.  The  pectorals  overlapt  the  hinder 
end  of  the  entoplastron.    The  whole  free  border  of  the  anterior  lobe  is  acute,  including  the  lip. 

Plate  45,  fig.  I,  represents  the  anterior  lobe  as  seen  from  above.  From  the  free  border  of 
the  lip  the  epiplastrals  are  thickened  backward  a  distance  of  20  mm.,  attaining  a  thickness  of 
13  mm.  This  is  then  suddenly  reduced  to  7  mm.,  forming  an  overhanging  and  somewhat 
excavated  ledge.  The  sides  of  this  thickened  surface  are  swollen  and  ornamented  with  ridges 
and  grooves,  the  marks  of  the  growth  of  the  gular  scutes.  Similar  markings  are  seen  on  the 
epiplastrals  of  C  muhlenhergi.  The  portions  of  the  gular  scutes  on  this  superior  surface  are  as 
wide  behind  as  at  the  free  border.  The  thickness  of  the  epiplastrals,  where  they  articulate 
with  the  hyoplastrals,  is  reduced  to  7  mm. 


292  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

Plate  45,  fig.  2,  represents  the  inguinal  region  of  the  hypoplastron  and  the  adjacent  part  of 
the  xiphiplastron,  seen  from  above.  The  free  border  is  acute.  The  beveled,  horn-covered 
surface,  on  the  upper  side,  is  18  mm.  wide  and  attains  a  thickness  of  9  mm.  At  its  inner  border 
the  thickness  falls  off  suddenly  to  6  mm.  The  lines  of  growth  of  the  femoral  scutes  are  dis- 
played on  this  surface.  Evidently  there  have  been  no  strongly  developt  inguinal  buttresses 
extending  inward  on  the  plastron  such  as  we  find  in  Echmatemys. 

Fig.  3  of  plate  45  presents  a  view  of  the  upper  side  of  the  left  xiphiplastron. 

Fig.  360  shows  the  same  bones  viewed  from  below.  Near  the  anterior  border  of  the 
fragment  of  the  hypoplastron  is  seen  the  abdomino-femoral  sulcus.  The  femoro-anal  sulcus 
crest  the  free  border  at  the  hinder  end  of  the  fragment. 

No.  6024  furnishes  the  front  of  the  nuchal  as  far  backward  as  the  bone  was  thickened, 
and  the  hinder  portion  of  the  left  xiphiplastron.  On  the  lower  surface  of  the  nuchal,  at  the 
midline,  the  thickened  portion  extends  backward  only  about  12  mm.;  but  toward  each  side 
this  increases  to  19  mm.  The  lines  of  growth  of  the  first  marginal  scutes  are  very  conspicuous 
on  this  surface.  On  the  upper  side  of  the  bone  the  nuchal  scute  is  observed  to  be  9  mm.  long, 
3  mm.  wide  in  front,  10  mm.  wide  behind,  and  to  be  more  deeply  notcht  posteriorly  than  in 
the  type.  The  piece  of  xiphiplastron  is  very  flat  on  the  under  side  and  has  the  free  border 
acute.  The  beveled  surface  on  the  upper  side  is  1 1  mm.  wide  and  ornamented  with  the  growth 
lines  of  the  femoral  scute.     There  was  a  notch  in  the  hinder  end  of  the  lobe. 

No.  6019  is  the  epiplastron  of  a  considerably  smaller  individual  than  the  type.  It  differs 
especially  in  having  the  upper  surface  of  the  lip  less  swollen,  the  greatest  thickness  being  only 
about  6  mm.    This  surface  shows  the  lines  of  growth  of  the  gulars. 

No.  6020  furnishes  a  portion  of  the  epiplastral  lip  and  a  fragment  of  the  hyoplastron. 
The  individual  seems  to  have  been  slightly  larger  than  the  type.  The  upper  surface  of  the  lip 
is  strongly  folded.  The  fragment  of  hyoplastron  belongs  behind  the  entoplastron  and  is  rep- 
resented in  fig.  360.  Its  thickness  is  only  about  4  mm.  The  pectoro-abdominal  sulcus  crest 
it  about  8  mm.  in  front  of  the  hyohypoplastral  suture. 

C.  morrisia  resembles  in  some  respects  Echmatemys  pusilla,  especially  in  the  epiplastral 
lip.    For  differences  see  the  last-named  species. 

This  species  is  named  in  honor  of  Mrs.  Lindsey  Morris  Sterling,  in  recognition  of  the 
skill,  accuracy,  and  artistic  taste  shown  by  her  in  the  preparation  of  the  great  majority  of  line 
drawings  in  this  work. 

Clemmys  hesperia  Hay. 

Plate  45,  figs.  4-7;   text-figs.  361-365. 

Clemmys  hesperia.  Hay,  Bull.  Geol.  Dept.  Univ.  Calif.,  in,  1903,  p.  238,  figs.  1-5. 

As  the  type  of  this  species,  is  taken  the  bone  bearing  number  2219  of  the  Paleontological 
Department  of  the  University  of  California.  This  is  the  left  hyoplastron,  having  the  outer  pos- 
terior portion,  which  enters  into  the  bridge,  missing.  Plate  45,  fig.  4,  and  text-fig.  361,  represent 
it  of  the  natural  size  and  viewed  from  below.  The  sutural  edges  are  present  which  met  the 
hyoplastron  of  the  opposite  side,  the  postero-lateral  border  of  the  entoplastron,  the  hinder 
extremity  of  the  epiplastron,  and  the  front  of  the  hypoplastron.  As  will  be  observed,  the 
humero-pectoral  sulcus,  represented  by  a  dotted  band,  crosses  the  entoplastron,  while  the 
pectoro-abdominal  sulcus  is  well  back  on  the  hyoplastron.  The  structure  of  these  parts  is 
identical  with  that  of  the  genus  Clemmys,  represented  to-day  on  the  Pacific  Coast  by  Clemmys 
marmorata.  The  free  border  of  the  bone  between  the  humeral  buttress  and  the  epihyoplastral 
suture  is  acute.  The  bone  thickens  until  it  reaches  a  thickness  of  7  mm.  where  the  suture  just 
named  meets  the  entoplastron.     At  the  inner  posterior  angle  the  bone  is  only  3  mm.  thick. 

In  lot  No.  2179,  believed  to  be  from  the  Rattlesnake  beds  of  the  Pliocene  but  possibly 
from  the  Mascall  beds  of  the  upper  Miocene,  there  is  a  portion  of  a  left  hyoplastron  which 
lacks  the  free  border,  but  which  as  far  as  it  is  represented  is  identical  with  the  specimen 
above  described.  The  writer  regards  it,  therefore,  as  belonging  to  the  same  species  and  to  the 
same  formation.  In  this  lot  are  included  also  a  portion  of  the  right  epiplastron  (plate  45,  fig. 
5;  text-fig.  362),  the  first  right  peripheral  bone  (plate  45,  fig.  6;  text-fig.  363),  a  right  periph- 
eral, apparently  the  eighth  or  ninth,  and  some  other  fragments.    The  epiplastron  has  the 


EMYDIDjS. 


293 


border  which  joined  its  fellow  of"  the  other  side  missing,  so  that  it  is  impossible  to  determine 
accurately  the  width  of  the  anterior  lip  of  the  plastron.  However,  this  bone  has  been  used 
in  making  the  restoration  of  the  front  of  the  plastron,  as  seen  in  fig.  361.  Plate  45,  fig.  5,  and 
text-fig.  362  show  this  bone  as  seen  from  below.  It  resembles  closely  the  same  bone  in  C. 
guttata,  except  that  its  upper  side  was  not  so  deeply  excavated  as  in  the  latter  species.  Accord- 
ing to  the  restoration  the  lip  had  a  breadth  of  about  34  mm. 

The  free  borders  of  the  epiplastron  are  subacute.  Seen  from  the  side,  this  border  runs 
forward  to  the  gulo-humeral  sulcus  and  then  turns  rather  abruptly  downward,  forward  and 
inward.  From  the  acute  edge  the  bone  thickens  rapidly,  until  a  thickness  of  7  mm.  is  attained. 
The  gulo-humeral  sulcus  probably  continued  backward  on  the  entoplastron. 

A  piece  of  the  thickened  border  of  the  xiphiplastron  of  this  specimen  is  present.  It  extends 
from  the  junction  with  the  hyoplastron  to  just  behind  the  femoro-anal  sulcus.  Most  of  the 
free  edge  is  broken  away,  but  enough  remains  to  show  that  it  was  acute.  It  thickens  gradually 
until,  at  the  inner  border  of  the  surface  above,  which  was  covered  with  horny  skin,  the  thick- 
ness is  6  mm.  The  femoro-anal  sulcus  comes  to  the  free  edge  19  mm.  behind  the  anterior  end 
of  the  bone. 

Plate  45,  fig.  6,  and  text-fig.  363  present  a  view  of  the  first  right  peripheral,  both  from  above 
and  from  the  right-hand  edge,  which  joined  the  second  peripheral.     The  left-hand  border 


361. 


^^.l"- 


.^6i. 


,?65. 


Figs.  361-365. — Clemmys  hesperta.     Portions  of  shell. 


XI. 


361.  Left  hyoplastron  of  type.    No.  1219  Univ.  California.    The  epiplastron  is  restored. 

362.  Portion  of  right  epiplastron.     Xi.     No.  2179  Univ.  California. 

363.  First  right  peripheral,  with  section  (a).    Xi.    No.  2179  Univ.  California. 

364.  Probable  ninth  peripheral,  with  a  section  (a).    No.  2179  Univ.  California. 

365.  Section  of  free  border  of  hypoplastron.    No.  5527  Univ.  California. 

joined  the  nuchal.  The  first  peripheral  resembles  closely  that  of  C.  guttata.  It  will  be  observed 
that  the  outer  anterior  angle  of  the  first  vertebral  scute  extends  outward  on  the  bone  here 
described  and  comes  into  contact  with  the  second  marginal  scute.  We  have  the  same  arrange- 
ment here  that  we  find  in  C.  leprosa,  as  shown  by  fig.  30,  page  102,  of  Boulenger's  Catalogue 
of  Chelonians.  This  indicates  that  the  first  vertebral  scute  was  broader  than  it  is  in  C.  guttata. 
The  peripheral  mentioned  above,  probably  the  ninth  of  the  right  side,  resembles  somewhat 
that  represented  by  plate  45,  fig.  7,  and  text-fig.  364;  but  it  is  shorter  antero-posteriorly  and 
higher,  the  fore-and-aft  dimension  being  15  mm.,  the  height  19  mm.  The  longitudinal  sulcus 
runs  closer  to  the  upper  border  than  in  fig.  364.  The  figure  just  referred  to  presents  a  view  of 
the  left  ninth  peripheral  of  an  individual  somewhat  larger  than  the  one  just  described.  It 
is  part  of  a  lot  numbered  552,  from  either  the  Mascall  or  the  Rattlesnake  beds.  Fig.  364 
shows  the  upper  surface  and  the  anterior  end  of  the  bone.  Accompanying  this  bone  there  is 
the  hinder  outer  angle  of  the  hypoplastron,  extending  from  the  suture  with  the  xiphiplastron 
to  the  inguinal  buttress.     A  view  of  a  section  of  the  bone  near  the  xiphiplastral  suture  is 


294  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

shown  in  fig.  365.  It  is  possible  that  this  lot  was  derived  from  the  Mascall  beds  and  does  not 
belong  to  this  species. 

From  a  comparison  of  the  bones  above  described  with  the  corresponding  parts  of  C. 
guttata  it  appears  that  the  carapace  of  C.  hesperia  attained  a  length  of  5  or  6  inches.  Unfortu- 
nately, the  writer  has  not  been  able  to  compare  the  fossil  species  with  C.  marmorata  of  the 
Pacific  Coast. 

From  the  Rattlesnake  beds  of  the  Pliocene,  Rattlesnake  Creek,  Oregon. 

Clemmys  saxea  Hay. 

Plate  45,  figs.  8-10;   tejt-fig.  366. 

Clemmys  saxea,  Hay,  Bull.  Gaol.  Dept.  Univ.  Calif.,  ill,  1903,  p.  241,  fig.  6. 

This  species  is  founded  on  rather  meager  materials,  being  represented  by  only  2  bones,  the 
pygal  and  a  posterior  peripheral.  These  bear  the  number  2192  of  the  museum  of  the 
University  of  California.  They  were  collected  from  the  Mascall  beds  of  the  upper  Miocene 
on  Beaver  Creek,  near  Crooked  River,  Oregon. 

The  pygal  originally  taken  as  type  of  the  species  is  represented  by  plate  45,  figures 
8,  9  and  text-fig.  366.  These  figures  present  views  of  the  bone  seen  from  above,  from  below, 
and  also  as  seen  from  the  sutural  edge;   and  therefore  both  the  size  and  the  thickness  of  the 

bone  are  indicated.  It  has  an  antero-posterior  length  of  18 
mm.  and  a  width  of  22  mm.  at  the  anterior  end  and  of  about 
10  mm.  at  the  posterior  end.  The  greatest  thickness  is  6 
mm.  On  the  superior  surface  the  bone  is  convex;  on  the 
inferior  surface  it  is  concave.  The  sulci  bounding  the  der- 
mal shields  are  deeply  imprest.  The  one  between  the  last 
vertebral  scute  and  the  supracaudal  scute  lies  well  down  on 
Fig.  366.-P^al  of  Clemmys  ^^^  y^^^^^  ^^  ;„  q  ^^.ttata.  In  C.  leprosa,  according  to  Dr. 
saxea.       ype.     XI.  Boulenger's  figure,  this  sulcus  lies  on  the  penultimate  pygal 

a,  outer  view;  b,  section.  ^^^^     yj^j^  ^^^^  j^  ^^  j.^jjjgj.  peculiar  form  and  will  doubt- 

less  be  easily  recognized  when  additional  materials  have  been  discovered. 

The  peripheral  accompanying  this  pygal  (plate  45,  fig.  10),  the  tenth  of  the  left  side, 
resembles  the  one  represented  by  fig.  7,  but  is  smaller,  and  the  horizontal  sulcus  has  evidently 
run  very  close  to  the  upper  border,  as  it  does  in  the  corresponding  bone  of  C.  leprosa.  Near 
the  hinder  end  of  the  upper  edge  of  the  bone  is  a  deep  pit  for  the  end  of  a  rib. 

It  is  possible  that  the  bones  described  under  Clemmys  hesperia,  belonging  to  Nos.  2179  and 
552,  belong  to  this  species,  there  being  some  doubt  regarding  the  level  in  which  they  occurred. 

Clemmys  ?  percrassa  Cope. 

Clemmys  percrassa,  CoPE,  Jour.  Acad.  Nat.  Sci.  Phila.  (2),  XI,  1899,  p.  194,  plate  xviii,  figs.  l-i^. — Hay, 
Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1903,  p.  449- 

The  described  specimens  of  the  present  species  are  in  the  collection  of  the  Philadelphia 
Academy  of  Science,  except  that  bone  which  is  represented  by  Cope's  fig.  le,  and  except 
apparently  also  those  bones  called  by  him  "No.  3."  All  these  bones  were  found  in  the  Pleisto- 
cene deposits  of  Port  Kennedy  Cave,  in  Montgomery  County,  Pennsylvania.  The  described 
remains  included  parts  of  two,  perhaps  of  three,  individuals. 

That  bone  which  is  called  by  Cope  his  "No.  i"  and  which  |furnisht  his  fig.  ib  must  be 
regarded  as  the  type  of  the  species.  This  figure,  like  most  of  those  of  that  paper,  is  poor  and 
shows  little  more  than  the  shape  of  the  face  figured.  This  bone  includes  a  considerable  portion 
of  the  right  xiphiplastron.  The  figure  presents  the  lower  face  of  the  bone.  The  hypoxiphiplastral 
suture  forms  the  upper  right  border  of  the  figure,  while  the  free  border  of  the  bone  is  on  the 
left.  There  is  present  a  portion  of  the  median  longitudinal  border.  This  makes  an  acute  angle 
with  the  hypoxiphiplastral  suture,  but  the  size  of  the  angle  can  hardly  be  determined.  The 
thickness  of  the  bone  here  is  9  mm.  or  10  mm.  From  this  border  the  bone  thickens  slowly 
along  the  hypoxiphiplastral  border  a  distance  of  30  mm;  then  it  rapidly  rises  to  the  summit  of 
a  wall   along  the  free   border.     The  outer  face   of  this  wall  is  nearly  perpendicular  and 


emydidje.  295 

the  summit  is  18  mm.  above  the  lower  face  of  the  bone.  Backward,  the  wall  descends,  so  that 
at  the  femoro-anal  sulcus  it  is  only  10  mm.  high  and  its  outer  face  is  not  so  steep.  The  length  of 
the  hypoxiphiplastral  suture  is  51  mm.  The  femoro-anal  sulcus  reaches  the  free  border  of  the 
bone  at  a  distance  of  30  mm.  behind  the  anterior  border. 

The  originals  of  Cope's  figs,  if,  if,  and  i^  are  portions  of  the  central  region  of  the  plastron. 
They  are  about  5  mm.  or  6  mm.  thick. 

Cope's  fig.  I  represents  what  to  the  present  writer  appears  to  be  the  right  eighth  peripheral. 
It  resembles  greatly  the  corresponding  bone  of  Testudo  tabulata.  The  following  are  the 
measurements  of  the  bone: 

Millimeters. 

Length  along  the  free  border 28 

Length  along  the  sutural  border  supposed  to  join  the  ninth  peripheral 42 

Greatest  thickness  of  this  border 12 

Length  along  sutural  border  supposed  to  join  the  seventh  peripheral 37 

Greatest  thickness  of  this  border 15 

Cope's  statement  that  the  greatest  thickness  is  1 1  mm.  is  an  error.  The  border  regarded 
as  the  posterior  is  convex  in  outline.  Cope  thought  that  this  was  the  anterior  border.  The 
free  border  (on  the  left  of  Cope's  figure)  is  acute.  The  costal  border  is  thickened,  rounded, 
and  smooth.  Evidently  it  formed  no  interlocking  suture  with  the  costal  bones.  The  sulcus 
(faintly  seen  in  Cope's  figure)  turns  slightly  forward  at  the  free  border  of  the  bone.  In  the 
thinner  articular  border  there  is  a  rough  groove  which  received  a  ridge  on  the  face  of  the  ninth 
peripheral.    On  the  supposed  anterior  articular  face  is  a  ridge  to  fit  into  the  next  bone. 

Cope's  fig.  id  represents  another  peripheral.  The  free  border  (on  the  left  of  Cope's  figure) 
is  acute  and  27  mm.  long.  One  sutural  border  (the  lower  of  the  figure  mentioned)  is  15  mm. 
thick  and  36  mm.  long.  The  opposite  border  is  somewhat  damaged  but  was  evidently  thinner. 
In  the  thicker  articular  face  there  is  a  groove  instead  of  a  ridge.  It  is  not  improbable  that  this 
is  a  second  peripheral. 

The  bone  represented  by  Cope's  fig.  la  is  difficult  of  identification  on  account  of  its 
damaged  state  of  preservation.  Cope  speaks  of  it  as  "a  piece  of  the  inguinal  marginal,  which 
shows  that  this  species  has  the  fixed  anterior  lobe  of  the  Emydidae. "  Instead  of  inguinal  he 
probably  meant  axillary.  Quite  certainly  the  bone  belongs  in  either  the  axillary  or  the  inguinal 
region.  The  form  and  the  great  thickness  of  the  border  of  the  hinder  lobe  and  the  smooth 
costal  borders  of  the  peripherals  render  it  probable  that  this  is  rather  a  species  of  Testudo 
than  oi  Clemmys. 

Clemmys  insculpta  (Leconte). 

Testudo  insculpta,  Leconte,  Lye.  Ann.,  New  York,  ill,  1830,  p.  112. 

Clemmys  insculpta,  BouLENGER,  Cat.  of  Chelonians,  1889,  p.  107. — Cope,  Jour.  Acad.  Nat.  Sci.  Phila. 
(2),  XI,  1 899,  p.  194. 

Professor  Cope,  as  cited  in  the  synonymy,  reports  the  finding  of  some  bones,  referred  to 
this  species,  in  the  Port  Kennedy  Cave,  Pennsylvania.  The  remains  were  very  fragmentary, 
and  there  is  a  possibility  that  they  may  belong  to  some  related  but  undescribed  species. 
C.  insculpta  is  yet  a  living  species  in  the  eastern  United  States. 

Genus  ECHMATEMYS  Hay. 

Shell  emydoid.  Neural  plates  mostly  hexagonal,  with  the  broad  end  forward.  Pygal 
bone  short,  the  transverse  sulcus  crossing  above  it  on  the  last  suprapygal.  Plastron  suturally 
articulated  with  both  the  peripherals  and  the  costals.  Axillary  buttresses  rising  above  the 
border  of  the  first  costal  and  articulating  with  its  inner  surface.  Inguinal  buttresses  ascending 
above  the  peripherals  and  articulating  with  the  inner  surfaces  of  the  fifth  and  sixth  costals. 
Usually  a  well-developt  epiplastral  lip.  Humero-pectoral  sulcus  usually  crossing  the  ento- 
plastron.  Skull  not  certainly  known,  but  almost  certainly  emydoid  in  general  structure  and 
with  the  triturating  surface  of  the  upper  jaw  narrow  and  with  no  ridge,  or  a  rudimentary  one, 
on  each  side.    Choanae  well  forward.    Lower  jaw  with  a  narrow  triturating  surface. 

Type:    Emys  septaria  Cope. 


296  FOSSIL    TURTLES    OK    NORTH    AMERICA. 

This  genus  is  known  principally  from  the  Bridger  Eocene,  but  also  from  the  Wasatch  and 
the  Uinta. 

In  the  absence  of  definite  knowledge  regarding  many  parts  of  the  anatomy  of  the  Eocene 
Emydidae  they  have  been  usually,  tho  sometimes  provisionally,  referred  to  the  genus  Emys. 
More  recently  they  have  been  supposed  to  belong  to  the  North  American  genera  Chrysemys 
or  Clemmys.  The  writer  has  exprest  himself  to  this  effect  in  1902  (Bibliog.  and  Cat.  Foss. 
Vert.  N.  A.,  p.  447)  and  again  in  1905  (Amer.  Geologist,  xxxv.,  p.  332).  Recently  there  has 
come  into  the  possession  of  the  American  Museum  of  Natural  History  a  considerable  number 
of  shells  of  Emydidae,  especially  from  the  Bridger  deposits.  Most  of  these  specimens  are  some- 
what damaged,  but  the  majority  of  them  are  in  condition  to  furnish  abundant  information. 
Unfortunately  no  skulls  accompany  these  remains.  A  single  dentary  bone  only  was  found  in 
company  with  a  good  plastron  and  some  fragments  of  the  carapace.  A  study  of  these  and 
other  accessible  materials  has  demonstrated  that  most  of  the  Bridger  species  of  Emydidae 
belong  to  a  hitherto  unrecognized  genus,  Echmatemys  (Hay,  Bull.  Amer.  Mus.  Nat.  Hist., 
xxii,  1906,  p.  27),  the  essential  characters  of  which  are  the  strongly  developt  buttresses  and 
the  feebly  developt  crushing  surfaces  of  the  jaws.  In  the  existing  North  American  genera  of 
Emydidae  the  buttresses  rise  little,  if  at  all,  above  the  lower  borders  of  the  costals  with  which 
they  come  into  contact.  In  Asia  there  are,  according  to  Boulenger,  four  genera  which  possess 
greatly  developt  axillary  and  inguinal  buttresses,  the  latter  articulating  with  the  fifth  and  sixth 
costals.  All  of  these  genera  differ,  however,  from  Echmatemys  in  having  the  triturating  surfaces 
of  the  jaws  broad,  and  those  of  the  maxillae  furnisht  with  one  'or  two  longitudinal  ridges. 
The  Eocene  genus  appears  therefore  to  be  well  separated  from  both  the  American  and  the 
Asiatic  forms. 

The  degree  of  development  of  the  buttresses  of  Echmatemys  appears  to  differ  among  the 
various  species.  It  is  doubtful  whether  in  any  of  them  the  buttresses  ascend  so  high  within  the 
carapace  as  they  do  in  the  Asiatic  species.  In  E.  wyomingensis  the  bases  of  the  inguinal  but- 
tresses begin  to  rise  perceptibly  from  the  upper  surface  of  the  plastron  at  a  point  less  than  half- 
way from  the  free  border  of  the  hinder  lobe  to  the  midline.  In  E.  arethusa  they  spring  from  the 
general  level  of  the  plastron  at  points  about  half-way  between  the  border  mentioned  and  the 
midline.  In  other  species  they  rise  still  nearer  the  midline.  There  appears  to  be  less  variation 
in  the  width  of  the  bases  of  the  anterior  buttresses.  In  E.  wyomingensis  these  buttresses 
ascend  but  little  above  the  lower  border  of  the  first  costals.  In  other  species  they  ascend  half- 
way to  the  neural  border  of  the  costals.  We  find  the  same  differences  of  development  in  the  case 
of  the  inguinal  buttresses,  the  height  to  which  they  ascend  varying  from  half-way  to  two- 
thirds  or  more  of  the  distance  from  the  lower  to  the  upper  border  of  the  costals  concerned. 

The  presence  of  these  buttresses  results  in  the  production  of  a  deep  sternal  chamber  on 
each  side.  In  a  specimen  oi  A.  septaria,  the  width  of  whose  carapace  is  225  mm.,  the  width 
of  the  space  between  the  inguinal  buttresses  is  only  about  80  mm. 

The  existence  of  these  buttresses  in  E.  septaria  was  recognized  by  Professor  E.  D.  Cope 
(Vert.  Tert.  Form.  West,  p.  130).  In  the  case  of  his  Emys  shaughnessiana  they  were  regarded 
as  less  well  developt.  On  the  contrary,  the  present  writer  finds  that  they  were  quite  as  broad 
and  high  as  in  E.  septaria. 

The  determination  of  the  species  of  this  genus  offers  great  difficulties.  There  is  among 
them  a  great  sameness  in  structure  and  general  appearance.  Few  of  them  are  markt  by 
trenchant  characters.  Yet  there  exist  differences  that  we  can  not  overlook.  Had  we  the 
skulls  belonging  to  the  shells  in  our  possession,  we  might  be  relieved  of  some  of  our  embarrass- 
ment; but  for  the  present  we  must  be  content  with  the  knowledge  and  the  conclusions  that  we 
can  derive  from  the  carapaces  and  the  plastra. 

Another  difficulty  arises  from  the  fragmentary  character  of  the  materials  on  which  some  of 
Dr.  Leidy's  species  from  the  Bridger  were  establisht.  If  it  is  difficult  to  identify  species  when 
we  have  practically  whole  shells,  it  is  far  more  difficult  when  we  have  only  a  fragment — for 
instance,  the  epiplastral  lip  or  a  fragment  of  the  carapace. 

In  studying  the  materials  in  his  hands  the  present  writer  has  been  compelled  to  recognize 
several  new  species.  It  is  not  unlikely  that  in  some  cases  he  has  erred;  but  it  has  appeared  to 
him  that,  better  than  the  lumping  together  of  forms  which  seem  to  be  distinct,  is  their  separa- 
tion under  special  names,  with  careful  descriptions,  leaving  to  future  writers,  in  the  possession 


EMYDID^. 


297 


of  more  and  better  materials,  the  determination  of  the  value  of  these  species.  In  establishing 
these  species  the  writer  has  drawn  on  all  the  structures  that  appeared  to  offer  assistance,  the 
general  form  of  the  shell,  the  proportions  of  its  various  regions,  the  degree  of  the  development 
of  the  buttresses,  the  forms  of  the  neural  bones,  the  form  of  the  epiplastral  lip,  the  form  and 
size  of  the  various  scutes,  etc.  The  condition  and  the  variations  of  the  same  structures  in 
various  living  species  have  been  examined.  As  a  result  of  this  study  it  is  to  be  recognized 
that  in  all  the  characters  there  is  more  or  less  fluctuation.  We  are  often  left  in  doubt  whether 
the  next  specimen  examined  will  not  contradict  the  conclusion  just  formed.  It  will  require  the 
examination  of  many  specimens  to  determine  the  range  of  the  variations.  It  will  be  observed 
that  there  exist  considerable  differences  among  the  forms  of  the  vertebral  scutes,  these  being 
in  some  cases  relatively  narrow  and  with  parallel  sides,  in  other  cases  relatively  broad  and 

367.  368.  369. 


374- 
Figs.  367-374.- 


372- 
-Echmatemys  sp.  indet. 


Figs. 


367.  Scapula  and  367^3  coracoid. 

368.  Right  humerus,  dorsal  surface. 

369.  Right  humerus,  radial  border. 

370.  Right  humerus,  ventral  surface. 


371- 
Portions  of  skeleton.     No.  1 1 ,525  Princeton  University. 

367-373,  x3,  374.  X  I. 

371.  Pelvis,  right  side. 

372.  Right  femur,  tibial  border. 

373.  Right  femur,  tibia  and  fibula,  dorsal  surface. 

374.  Terminal  and  penultimate  phalanges. 


with  perhaps  strongly  bracketed  sides.  It  is  believed  that  some  considerable  reliance  may  be 
placed  in  these  forms  as  indicating  specific  differences.  Little  aid  in  the  differentiation  of  the 
species  has  been  derived  from  the  proportions  of  the  plastral  scutes.  The  usually  well-developt 
axillary  and  inguinal  scutes  seem  to  offer  valuable  characters.  Sometimes  the  axillary  scutes 
extend  backward  and  join  broadly  the  fifth  marginals;  in  other  cases  they  fall  far  short  of 
these  marginals.  In  some  forms  the  inguinal  scutes  articulate  with  the  sixth  marginals,  while 
in  others  they  lack  much  of  attaining  the  marginals  mentioned. 

As  already  stated,  little  is  certainly  known  about  the  skulls  of  the  members  of  this  genus. 
In  the  collection  of  fossil  reptiles  belonging  to  Princeton  University  there  is  a  portion  of  a  skull 
of  an  emyd  that  in  all  probability  belongs  to  some  species  of  this  genus.  It  is  represented  by 
figs.  11,12  and  13  of  plate  45.  It  resembles  much  the  skull  of  Chrysemys  picta,  altho  larger. 
It  differs  especially  in  having  the  longitudinal  ridge  on  the  triturating  surface  of  the  maxilla 


298  FOSSIL   TURTLES   OF    NORTH    AMERICA. 

Still  less  developt  than  in  Chrysemys.    The  dentary  bone  of  E.  wyomingensis  (figs.  398,  399) 
agrees  well  with  the  maxilla  of  this  skull. 

Text-figs.  367-374  represent  various  parts  of  the  skeleton  of  the  same  individual. 

It  is  evident  that  this  genus  began  its  existence  at  least  as  far  back  as  the  Wasatch.  An 
examination  of  Cope's  Emys  lativertebralis  (Wheeler's  Surv.  100  Merid.,  iv,  part  ii,  plate 
xxviii,  figs.  I,  2)  shows  that  it  possest  strongly  developt  inguinal  buttresses,  which  articulated 
with  the  visceral  surfaces  of  the  fifth  and  sixth  costals.  The  genus  continued  apparently  until 
the  middle  of  the  Uinta,  as  evidenct  by  the  presence  there  of  E.  callopyge  and  E.  uintensis. 

We  are  unable  to  determine  as  yet  the  relationships  of  this  genus  to  Kachuga,  Callagur, 
Batagur,  and  Hardella,  of  Asia.  It  seems  possible  that  some  species  of  Echmatemys  made  its 
way  to  that  continent  from  America  and  thru  a  modification  of  its  jaws  gave  origin  to  these 
genera. 

Key  to  the  Described  Species  of  Echmatemys. 

A^.  Wasatch   and   Green   River   species. 
a^.  No  dorsal  keel. 

1.  Neurals  broader  than   long;    gulo-humeral  sulcus  crossing  behind  entoplastron; 

gular  scutes  reaching  entoplastron lativertebralts 

2.  Neurals  unknown ;    gular  scutes  not   reaching   the   entoplastron ;    gulo-humeral 

sulcus  crossing  on  entoplastron ciboUensts 

3.  Sulci  of  carapace  deeply  imprest;  costals  swollen  just  outside  of  costo-vertebral 

sulci;  bones  thick  and  heavy testudinea 

4.  Bones  rather  thin;   beveled  surface  on  upper  side  of  hinder  plastral  lobe  narrow.  .   euthneta 
a^.  A  dorsal  keel;  bones  of  carapace  deeply  imprest  by  sulci;  bones  thin megaulax 

A^.  Bridger  species. 

a^.  Inguinal  buttresses  not  extending  half-way  from  free  border  of  hinder  lobe  to  midline. 

1.  Vertebral  scutes  and  neural  bones  considerably  longer  than  wide wyomingensis 

2.  Vertebral  scutes  and  neural  bones  wider  than  long pusilla 

c?.  Inguinal  buttresses  reaching  half-way  from  free  border  of  hinder  lobe  to  midline. 

i'.  Third  vertebral  scute  about  seven-tenths  its  length. 

1.  Fourth   neural  octagonal haydeni 

b^.  Third  vertebral  about  eight-tenths  its  length. 

2.  Third  vertebral  about  0.78  its  length;    anterior  lobe  not  expanded.  . .  .   stevensontana 

3.  Third  vertebral  0.80  its  length;  anterior  lobe  of  plastron  expanding  in  front 

of  axillx septaria 

4.  Third  vertebral  about  0.81  its  length;  epiplastral  lip  contracted,  tootht.  .  .  .   arethusa 

5.  Third  vertebral  0.82  its  length;  axillary  buttress  rising  high;  marginal  scutes 

not  high  on  anterior  peripherals cyane 

6.  Third  vertebral  0.82;   humero-pectoral  sulcus  crossing  behind  entdplastron; 

free  borders  of  shell  in  front  obtuse shaughnessiana 

b^.  Third  vertebral  about  nine-tenths  its  length  or  more. 

7.  Third  vertebral  0.87  its  length;   second  vertebral  still  wider;    anterior  mar- 

ginals rising  high  on  peripherals ocyrrhoe 

8.  Third  vertebral  0.97  its  length  and  urn-shaped;  sulci  not  in  deep  valleys; 

axillary  scutes  not  reaching  the  fifth  marginal legle 

9.  Third   vertebral  as  wide  as  long ;    the   sulci   of  carapace   in  deep  valleys ; 

axillary  scutes  broadly  joining  fifth  marginals naomi 

a'.  Little  known  species;    said  to  have  a  very  wide  epiplastral  lip  and  a  deeply  notcht 

plastron latilahiata 

A*.  Uinta  species. 

a*.  Vertebral  scutes  urn-shaped,  the  first  narrower  than  the  others callopyge 

a?  Vertebrals  with  straight  sides;    the  front  the  widest uintensis 

Echmatemys  lativertebralis  (Cope). 
Text-figs.  375-378. 

Emys  latilabiatus.  Cope,  Syst.  Cat., etc..  Report  to  Engineer  Dept.  U.S.  Army,  1875,  p.  36;  Ann.  Report 
Chief  Engineers,  1875,  App.  LL,  p.  1016,  of  reprint,  p.  96.     Not  E.  latilabiatus  of  1872. 

Emys  lativertebralis  CoPE,  1877,  Wheeler's  Surv.  West  looth  Merid.,  iv,  part  ii,  p.  53,  plate  xxvii,  figs. 
1-3;  plate  xxviii,  figs.  l,  2;  Amer.  Naturalist,  xvi,  1882,  p.  991,  fig.  lo;  Vert.  Tert.  Form.  West, 
1884,  p.  129. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  448. 


EMYDIDjE. 


299 


The  known  remains  of  this  species  were  collected  in  the  Wasatch  beds  of  northern  New 
Mexico  and  were  at  first  referred  by  Cope  to  his  species  Etnys  latilabiatus  of  the  Bridger  beds. 
The  specimens  mentioned  by  Cope  are  at  present  in  the  U.  S.  National  Museum  and  have  been 
examined  by  the  writer. 

The  type  specimen,  that  figured  by  Cope,  was  restored  from  loose  fragments,  and  various 
portions  were  missing.  The  length  of  the  restored  carapace  (fig.  375)  is  given  as  350  mm. 
It  follows  from  this  that  Cope's  figure  is  not  half  the  size  of  nature,  as  is  stated,  but  somewhat 

less.  The  width  was  close  to  284  mm.  The  front  was  broad  and 
rounded,  the  rear  nearly  truncate.  The  neurals  are  characterized 
by  their  great  breadth  as  shown  in  the  table  herewith. 
The  first  suprapygal  is  35  mm.  long  and  29  mm.  wide. 
On  none  of  the  neurals  is  there  any  trace  of  a  median  keel. 
The  first  pygal  was  35  mm.  long  and  29  mm.  wide.  The  second 
appears  to  have  been  about  21  mm.  long  and  49  mm.  wide. 
The  nuchal  bone  had  a  width  in  front  of  about  58  mm. 

The  costal  bones  presented  no  considerable  differences  in 
the  widths  of  their  opposite  ends.  They  are  devoid  of  sculpture. 
One  of  them,  probably  the  third,  had  a  width  of  24  mm.  in  the 
middle  of  its  length  and  a  thickness  of  5  mm.  On  the  inner 
surface  of  the  first  and  near  to  its  peripheral  border  is  a  short  articular  surface  for  the  reception 
of  the  axillary  buttress.  This  surface  shows  that  the  buttress  did  not  ascend  so  high  as  did 
that  of  some  species  of  the  genus.  Above  the  scar  for  the  buttress  is  a  low  ridge,  that  per- 
taining to  the  rib  of  the  first  costal. 


Neural. 

1 

Length. 

Width. 

I 

2 

is 

36 

JO 

34 

26 

36 

IS 

37 

'9 

39 

'4 

40 

22 

37 

377- 


Figs.  375-378. — Echmatemys  lativertelralis 
375.  Carapace 


378. 


Carapace  and  plastron  of  type.     Xj. 


Restored  portions  shown  by  interrupted  lines.       376.  Plastron.       377.  Epiplastral  lip,  upper  surface. 
378.  Right  side  and  upper  surface  of  hinder  lobe  of  plastron. 

The  inguinal  buttress  articulated  with  the  fifth  and  sixth  costals.  As  stated  by  Cope  and 
shown  by  the  type,  the  buttress  ascended  about  two-fifths  the  distance  from  the  lower  border 
of  the  costal  to  the  upper  border. 

The  free  peripheral  bones  are  large,  thin,  and  recurved.  The  second  and  the  eleventh  are 
flared  the  most.  The  peripherals  of  the  bridge  were  not  crost  by  a  sharp  keel  running  from 
the  anterior  to  the  posterior  free  peripherals,  a  condition  regarded  as  showing  that  the  shell 
was  not  deprest.     The  first  peripheral  had  a  length  of  48  mm.  along  the  free  border.     Its 


Scute. 

Length. 

Width. 

I 

6o 

68 

2 

62 

64 

3 

6o 

62 

4 

SO 

67 

S 

5^ 

95 

300  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

height,  or  extent  at  right  angles  with  the  free  border,  was  about  45  mm.  The  eighth  peripheral 
had  a  length  along  the  free  border  of  41  mm.  and  a  height  of  about  60  mm.  The  pygal  had 
a  height  of  30  mm.  and  a  width  of  35  mm.  It  was  moderately  recurved  and  transversely 
convex  above. 

The  sulci  bounding  the  horny  plates  are  well  markt.  Professor  Cope  describes  the  first 
vertebral  scute  as  being  longer  than  wide,  the  second  as  long  as  wide,  the  third  a  little  wider 
than  long,  the  fourth  still  wider;  but  a  study  of  his  figure  does  not  in  all  respects  confirm  this 
statement.  The  dimensions  in  the  accompanying  table  are  estimated  from  his  figure,  as  the 
bones  of  the  carapace  are  now  in  a  disturbed  condition. 

The  costo-marginal  sulci  have  pursued  their  course  considerably  below 
the  costo-peripheral  sutures. 

Professor  Cope  states  that  the  length  of  the  plastron  (fig.  376)  was 
290  mm.,  and  the  specimen  confirms  the  statement.  He  also  informs  us 
that  the  bones  were  not  thick;  but  no  measurements  are  given.  The  ante- 
rior lobe  had  a  length  of  about  85  mm.  and  a  width  of  about  140  mm.  at  the 
base.  Cope's  measurements  are  somewhat  greater  than  those  here  given. 
The  anterior  lip  projects  somewhat  beyond  the  general  curvature  of  the 
lobe  and  is  truncated.  Seen  from  above  the  lip  is  very  concave  from  side 
to  side  and  spout-shaped  (fig.  377).  On  each  side  is  a  rather  deep  cleft  which  separates  from 
the  remainder  of  the  lip  a  rather  prominent  tooth.  The  thickening  on  the  upper  side  of  the  lip 
extends  backward  about  35  mm.  At  the  hyoepiplastral  suture  the  beveled  horn-covered 
surface  has  a  width  of  about  25  mm. 

The  entoplastron  has  a  length  of  42  mm.  and  a  width  of  55  mm.  Its  thickness  is  13  mm. 
The  bridge  is  about  no  mm.  wide. 

The  length  of  the  hinder  lobe  is  105  mm.,  85  mm.  along  the  midline;  its  width  is  140  mm. 
There  is  a  posterior  notch  which  has  a  width  of  38  mm.  and  a  depth  of  20  mm.  The  beveled 
horn-covered  surfaces  on  the  upper  side  of  the  hinder  lobe  (fig.  378)  have  a  width,  at  the 
hypoxiphiplastral  suture,  of  27  mm. 

At  the  crossing  of  the  median  longitudinal  and  the  hyohypoplastral  sutures  the  bones  are 
10  mm.  thick.  The  greatest  thickness  of  the  epiplastrals  is  i6  mm.  The  inner  border  of  the 
beveled  area,  just  behind  the  inguinal  notch,  is  13  mm. 

The  inguinal  buttress  begins  to  rise  from  the  floor  of  the  plastron  at  a  line  not  quite  half- 
way from  the  free  border  of  the  lobe  to  the  midline. 

The  gular  scutes  are  53  mm.  long;  the  humerals,  32  mm.;  the  pectorals,  41  mm.;  the 
abdominals,  66  mm.;  the  femorals,  45  mm.;  the  anals,  34  mm.;  all  measured  along  the  mid- 
line. The  humero-pectoral  sulcus  falls  slightly  behind  the  entoplastron,  resembling  in  this 
respect  E.  shaughnessiana  (Cope).  However,  in  one  of  Cope's  specimens  the  sulcus  crept 
over  on  the  posterior  margin  of  the  entoplastron.  It  is  not  certain,  on  the  other  hand,  that  this 
specimen  (Cope,  Wheeler's  Survey,  iv,  plate  xxvii,  fig.  3)  belongs  to  the  present  species. 
Cope  collected  altogether  five  specimens  of  this  turtle,  two  of  them  larger  than  the  type, 
and  one  much  smaller.    The  latter  showed  traces  of  a  median  carina  on  some  of  the  neurals. 

Echmatemys  ciboUensis  (Cope). 

Text-fig.  379. 

Emys  (f)stevensonianus,  CoPE,  Syst.  Cat.  Vert.  Eocene  New  Mexico,  Report  to  Engineer  Dept.  U.  S. 

Army,  1875,  p.  36.  ,  ^        •  s 

Emys  stevensonianus,  Cope,  Ann.  Report  Chief  Engineers  for  1875,  Append.  LL,  p.  995  (of  reprint,  75). 
Emys  ciboUensis,  CoPE,  Wheeler's  Surv.  W.  looth  Merid.,  vol.  iv,  part  ii,  p.  57,  plate  xxvii,  fig.  4; 

plate  xxviii,  figs.  3-6. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  pp.  447. 

The  figured  specimen  of  the  type  of  this  species  belongs  to  the  U.  S.  National  Museum  and 
has  the  catalog  number  2576.  The  carapace  appears  to  be  missing.  Cope  states  that  the 
species  was  based  on  a  single  imperfect  individual,  in  which  some  of  all  the  characteristic 
parts  were  present,  except  the  neurals.  Of  the  parts  in  his  possession  Cope  figured  the  epi- 
plastral  lip,  as  seen  from  above  and  from  below;  the  border  of  the  hinder  lobe,  as  seen  from 
above;  and  two  peripheral  bones. 


EMYDIDiS.  301 

The  type  specimen  was  obtained  from  the  Wasatch  beds  of  New  Mexico.  The  more  exact 
locality  is  given  as  the  Gallinas  River. 

In  his  great  work  on  the  Vertebrata  of  the  Tertiary  Formations  of  the  West,  publisht  in 
1884,  Cope  exprest  the  opinion  that  his  Emys  cibollensis  may  have  been  founded  on  a  larger 
individual  of  his  Emys  euthneta  of  the  "red  beds"  at  Black  Buttes,  Wyoming.  To  the  present 
writer,  after  comparing  Cope's  descriptions  and  figures  and  the  types  of  the  two  forms  and  after 
study  of  such  materials  of  E.  euthneta  as  are  accessible.  Cope's  opinion  of  1884  seems  erro- 
neous, for  reasons  to  be  mentioned  below. 

The  individual  forming  Cope's  type  was  somewhat  smaller  than  the  one  which  formed  the 
type  of  his  E.  lativertebrahs.  Its  plastron  was  about  250  mm.  long,  carapace  about  310  mm. 
When  Cope  described  this  species  he  regarded  its  relationships  as  being  with  his  Emys  lati- 
vertebralis,  but  he  found  the  peripheral  bones  of  the  latter  larger  and  thinner,  and  both  the 
anterior  lobe  of  the  plastron  and  the  entoplastron  relatively  longer. 

Cope  figures  no  costal  bones,  but  he  gives  the  width  of  one  as  22  mm.,  the  thickness  as 
6  mm.    A  costal  of  £.  lativertebralis  had  a  width  of  24  mm.  and  a  thickness  of  5  mm. 

Of  the  peripheral  bones  Cope  says  that  they  are  not,  or  but  little,  recurved.  He  figures 
two  of  these,  but  he  does  not  state  whether  they  are  anterior  or  posterior  peripherals.  Evidently 
both  were  imperfect.  They  probably  belonged  behind,  and  included  the  portion  between  the 
free  border  and  the  costo-marginal  suture.  Cope  gives  the  length  of  one  peripheral  as  being 
30  mm.  and  its  thickness  as  9  mm.;  but  the  thickness  of  those  figured  must  have  been  about 
12  mm.  The  peripherals  oi  E.  lativertebralis  differ  in  being  higher  and  thinner.  On  the  other 
hand,  the  posterior  peripherals  oi E.  euthneta  were  more  recurved. 

The  anterior  lobe  of  the  plastron  to  the  hinder  border  of  the  entoplastron  is  65  mm.  long. 
The  anterior  lip  (fig.  379)  projected  somewhat  and  is  slightly  concave  in  outline.    At  each  side 

is  a  rather  prominent  tooth,  but  there  is  no  cleft  separating  it 
from  the  remainder  of  the  lip  as  there  is  in  E.  lativertebralis. 
The  width  of  the  lip,  measured  to  the  gulo-humeral  sulci,  is 
54  mm.    The  thickening  on  the  upper  surface  of  the  lip  extended 
backward  23  mm.    From  each  lateral  tooth  there  extends  back- 
ward a  broad  ridge.    At  the  hyoepiplastral  suture  the  beveled 
surface  is  23  mm.  wide.     The  entoplastron  has  a  length  of  36 
Fig.  ^■jg.—Echmatemys  cibol-     "i""-'  ^  ^^^^^  °^  55  mm.,  and  a  thickness  of  7  mm.    As  stated 
lensis.  Epiplastral  lip  of  type.      ^V  Cope,  the  bone  was  transversely  diamond-shaped.     To  the 
Xj.    No.  2576  U.  S.  N.  M.     present  writer,  the  epiplastral  lip  appears  to  be  quite  different 

from  that  of  Emys  euthneta. 
The  hinder  lobe  had  a  total  length  of  95  mm.  and  at  the  rear  was  a  deep  notch.  There  was 
a  broad  beveled  area  at  the  border  of  the  upper  surface,  and  at  the  hypoxiphiplastral  suture 
this  was  22  mm.  wide.  This  surface  appears  to  have  been  strongly  imprest  by  the  lines  of 
growth  of  the  horny  scutes.  In  Cope's  Emys  euthneta  this  surface  was  relatively  narrow  (Vert. 
Tert.  Form.  West,  plate  xviii,  fig.  42). 

The  estimate  of  the  present  writer  is  that  the  length  of  the  anterior  lobe  of  £.  lativertebralis 
equaled  0.75  of  the  length  of  the  hinder  lobe;  in  E.  cibollensis  about  0.68. 

The  arrangement  of  the  scutes  of  the  anterior  lobe  of  E.  cibollensis  is  quite  different  from 
that  of  E.  lativertebralis,  since  the  gulars  of  the  former  do  not  reach  backward  to  the  ento- 
plastron and  the  humerals  overlap  extensively  this  bone.  The  gulars  of  the  present  species  had 
a  length  of  25  mm.  and,  taken  together,  a  width  of  54  mm.  In  E.  euthneta  the  gulars  had 
evidently  a  length  fully  equal  to  their  combined  widths. 

There  appears  to  be  no  good  reason  why  this  species  should  not  be  referred  to  Echmatemys. 

Echmatemys  ?  megaulax  (Cope). 
Plate  45,  figs.  14,  15;  text-figs.  380-383. 

Emys  megaulax,  CoPE,  Sixth  Ann.  Report  U.  S.  Geol.  Surv.Terrs.,  1872  (1873),  p.  628;  Vert. Tert.  Form. 

West,  1884,  pp.  129,  132,  plate  xviii,  figs.  26-33. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902, 

p.  448. 
Emys  pachylomus,  CoPE,  Sixth  Ann.  Report  U.  S.  Geol.  Surv.  Terrs.,  1872  (1873),  p.  629. 


-/ 


302  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

Professor  Cope  tells  us  that  this  species  was  based  on  fragmentary  specimens  of  5  or  6 
individuals.  Portions  of  these  are  now  in  the  American  Museum  of  Natural  History,  but  the 
bones  figured  by  Cope  are  in  the  U.  S.  National  Museum  at  Washington,  and  have  the  catalog 
number  4061.  The  types  and  other  specimens  obtained  by  Cope  were  collected  in  the 
Green  River  beds  of  the  Wasatch  formation,  at  Black  Buttes,  Wyoming,  in  1872.  A  note  in 
Professor  Cope's  handwriting,  accompanying  some  specimens  at  Washington,  states  that  they 
were  found  in  the  first  lignite  beds  of  the  Eocene  at  Black  Buttes. 

As  stated  by  Cope,  the  markt  peculiarity  of  the  present  species  was  the  broad  and  abruptly 
sunken  sulci  which  separated  the  epidermal  scutes.  There  was  a  dorsal  carina  and  this  was 
conspicuously  intersected  by  the  sulci  which  crost  it.  The  neurals  are  relatively  broad.  Cope 
gives  the  length  of  one  as  17  mm.  and  the  width  as  18  mm.  A  neural  in  the  American 
Museum,  No.  1120,  is  19  mm.  long  and  23  mm.  wide  at  the  broader  end;  its  thickness  at  the 
border  for  the  costal  is  5  mm.  Sometimes  the  carina  is  broader  in  front  of  the  sulcus  which 
crosses  it  and  sometimes  narrower.  Sometimes  (Cope's  figure  32)  the  sulci  are  shallow. 
The  neural  which  furnisht  the  figure  just  referred  to  has  a  thickness  of  5.5  mm.;  while 
the  others  figured  are  only  about  4  mm.  thick  at  the  borders.  Cope's  fig.  28  does  not  repre- 
sent a  neural,  but  probably  the  hinder  suprapygal.  If  so,  the  hinder  marginal  scutes  extended 
upon  it.  The  figure  is  inverted.  Fig.  14,  plate  45,  is  taken  from  No.  1184  of  the  American 
Museum.    It  is  either  the  third  or  fifth  neural. 

The  peripherals  are  rather  thin,  and  they  flare  somewhat  upward  toward  the  free  border. 
One  figured  by  Cope  (his  plate  xviii,  fig.  29)  had  a  width  of  16  mm.,  a  height  of  23  mm.,  and 


f^ 


L 


380.  381-  382-  3^3- 

Figs.  380-383. — Echmatemys  megaulax.     Peripherals  and  entoplastron.     XL 

380.  Section  across  posterior  peripheral.    No.  1184  A.M. N. H. 

381.  Right  third  or  left  seventh  peripheral.    No.  1184  A.M.N.H. 

382.  Section  of  peripheral  of  fig.  381. 

383.  Entoplastron  of  type  of  Emys  pachyhmus  Cope.     Specimen  in  A.M.N.H. 

a  thickness  of  5  mm.  It  appears  to  be  either  the  eighth  or  the  tenth  of  the  right  side.  In  the 
upper  border  is  a  pit  for  a  rib.  This,  like  others  belonging  to  Cope's  specimens,  had  the  sulci 
deeply  imprest.  Cope's  fig.  31  is  almost  certainly  the  first  right  peripheral  and  is  quite  dif- 
ferent from  the  corresponding  bone  of  E.  euthneta,  being  5.2  mm.  thick  where  it  joined  the 
nuchal,  while  that  of  E.  euthneta  is  9  mm.  thick.  Cope's  fig.  30  appears  to  be  that  of  the 
second  right  peripheral,  altho  it  does  not  join  the  first  accurately.  Fig.  15  of  plate  45  is  from 
a  peripheral  of  lot  No.  1 184.  Its  breadth  at  the  free  border  is  19  mm.;  its  height,  20  mm.;  its 
thickness,  5  mm.  At  the  free  border  the  edge  is  rather  abruptly  turned  upward.  Another 
(text-fig.  380,  section)  is  greatly  thickened  below  the  costo-marginal  sulcus.  Both  of  these  are 
posterior  peripherals.  Text-figs.  381,  382  represent  the  right  third  or  the  left  seventh  periph- 
eral. Its  width  is  17  mm.;  its  height,  19  mm.;  the  thickness  of  the  anterior  sutural  border, 
7  mm.  On  the  inner  face  is  a  rough  groove  for  the  buttress.  If  this  is  the  third  peripheral  it 
presents  in  its  acute  free  border  a  great  contrast  to  that  of  E.  testudmea.  The  sulci  are  not 
broad  and  deep  as  they  are  in  other  posterior  peripherals.  It  resembles  other  anterior  periph- 
erals in  its  moderate  height. 

There  is  little  or  no  authentic  material  to  throw  light  on  the  structure  of  the  plastron  of 
this  species. 

A  lot  of  bones,  including  portions  of  more  than  one  individual,  probably  of  more  than  one 
species,  bears  Cope's  label  "Emys  pachyhmus.  Black  Buttes."  Among  them  is  an  entoplastron 
which  evidently  is  the  one  described  by  Cope  in  the  Sixth  Annual  Report  of  the  U.  S.  Geological 


.:.'.    .        EMYDID^.  -  303 

Survey,  page  629.  This  bone  (fig.  383)  has  a  length  of  23  mm.,  a  width  of  30  mm.,  and  a 
thickness  of  6  mm.  It  is  quite  certain  that  it  does  not  belong  with  the  other  bones  of  the  lot, 
all  of  which  belonged  to  smaller  turtles.  In  this  lot  are  peripherals  which  belong  to  E.  megau- 
lax,  having  the  scutal  sulci  deeply  imprest.  On  some  costals  and  a  neural  present  they  are  not 
so  deeply  imprest.  To  the  writer  it  appears  that  the  peripherals  are  to  be  taken  as  the  type  of 
this  supposed  species,  and  that  these  belong  to  E.  megaulax. 

Cope  (his  plate  xviii,  fig.  33)  has  figured  a  costal  bone,  apparently  the  sixth  of  the  left  side. 
The  thickness  of  the  posterior  border  is  only  2.5  mm.  while  that  of  the  anterior  border  is  7  mm. 
This  great  thickness  indicates  that  it  united  with  the  fifth  costal  to  form  a  ridge  for  a  strong 
inguinal  buttress.  For  this  reason  the  species  is  referred  provisionally  to  Echmatemys.  The 
proximal  end  of  this  costal  shows  that  the  sixth  neural  was  short,  12  mm.,  at  the  costal  border; 
also  that  the  fifth  neural  was  probably  octagonal.  On  this  costal  just  outside  of  the  area  of  the 
fourth  vertebral  scute,  there  is  a  prominent  boss. 

So  far  as  known  at  present,  this  species  differs  from  E.  testudinea  in  having  the  neurals 
keeled  and  the  keel  notcht  at  the  crossing  of  the  sulci;  and  in  having  the  posterior  peripherals 
thin  and  deeply  and  broadly  imprest  by  the  sulci.  It  must  be  stated,  however,  that  little  is 
known  about  the  neurals  of  E.  testudinea  and  little  or  nothing  about  the  plastron  of  E.  megau- 
lax. It  appears  that  the  shell  of  E.  megaulax  was  comparatively  thin;  that  of  E.  testudinea 
rather  thick  and  heavy. 

Echmatemys  testudinea  (Cope). 
Plate  45,  figs.  16,  17;   text-figs.  383-388. 

Notomorpha  testudinea,  CoPE,  Proc.  Amer.  Philos.  Soc,  XII,  1 872,  p.  475. 

Emys  testudineus,  CoPE,  Sixth  Ann.  Report  U.  S.  Gaol.  Surv.  Terrs.,  1872  (1873),  ?•  ^27;  Wheeler's 

Surv.  W.  looth  Merid.,  iv,  part  ii,  1877,  p.  58. 
Emys  testudinea, Cov^yNcrt.Te.vt.  Form.  West,  1884,  pp.  129,  I34,plate  xxiii.figs.  12, 13. — HAy,Bibliog. 

and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  448. 

Professor  Cope  states  that  this  species  was  represented  in  his  collection  by  4  or  more 
individuals.  These  he  secured  in  the  Green  River  beds,  as  stated  on  his  labels,  1 1  miles  east 
of  Evanston,  Wyoming.  These  beds  are  a  portion  of  the  Wasatch  formation.  All  the  indi- 
viduals collected  by  Cope  were  imperfect  and  fragmentary.  Of  his  specimens  he  presented 
figures  of  only  an  entoplastron  and  the  left  border  of  the  hinder  lobe  of  a  plastron  seen  from 
above.  These  figured  specimens  are  now  in  the  National  Museum,  at  Washington,  with  the 
catalog  number  4103. 

In  the  Cope  collection  at  the  American  Museum  of  Natural  History  there  are  several  lots 
of  turtle  bones  bearing  Cope's  labels  stating  that  they  are  Emys  testudinea.  Besides  lacking 
the  figured  specimens,  these  lots  contain  occasionally  bones  of  more  than  one  individual,  and 
we  can  not  always  be  sure  that  they  do  not  include  parts  of  other  species.  To  add  to  the  con- 
fusion. Cope's  table  of  measurements  (Tert.  Vert.,  p.  135)  can  hardly  be  relied  on;  for  while 
he  gives  the  width  of  the  plastron  at  the  axilla  as  86  mm.,  which  is  probably  correct,  he  states 
that  the  length  of  the  plastron  from  the  axilla  is  approximately  50  mm.  Whether  this  is  an 
error  or  whether  he  referred  to  the  anterior  lobe  alone,  it  is  impossible  to  say.  In  that  table 
the  thickness  of  the  hyoplastron  at  the  entoplastron  is  said  to  be  99  mm.  and  at  the  hypoplastron 
as  5  mm.,  both  of  which  statements  are  obvious  errors.  What  the  facts  were  we  can  only 
surmise. 

In  one  lot,  that  bearing  the  American  Museum's  catalog  number  1178,  there  are  found 
the  proximal  ends  of  two  costal  plates,  almost  certainly  the  third  and  the  fourth  of  the  right 
side  (plate  45,  fig.  16).  These  are  probably  the  ones  mentioned  by  Cope  in  his  description  of 
1884  as  belonging  to  his  second  specimen.  The  fourth  has  a  width  of  17  mm.,  the  fifth  a 
width  of  about  20  mm.  As  stated  by  Cope,  the  sulci  run  in  grooves.  These  grooves  are  broad, 
while  the  sulci  themselves  are  very  narrow.  The  surface  of  these  costals  is  swollen  just  outside 
the  sulci,  forming  what  Cope  has  called  a  "hump."  The  thickness  of  the  fourth  thru  this 
hump  is  8  mm.  Where  this  costal  articulated  with  the  neural  the  thickness  is  7  mm.,  while 
that  of  the  fifth  is  8  mm.  The  rib-heads  were  not  strongly  developt.  The  external  surface  of 
these  bones  shows  the  lines  of  growth  of  the  horny  scutes.  The  sulci  which  limited  laterally 
the  second  and  the  third  vertebral  scutes  run  at  a  distance  from  the  neural  border  of  only  5 


304 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


mm.  on  the  fourth  costal  and  6.5  mm.  on  the  fifth.  This  indicates  that  these  vertebrals  were 
very  narrow,  probably  about  30  mm. 

No.  118 1  has  a  label  in  Cope's  handwriting  which  indicates  that  it  is  a  portion  of  his 
principal  specimen  (Vert.  Tert.  Form.  West,  p.  134),  but  only  a  part  of  the  bones  described  is 
present.  Among  these  are  portions  of  both  the  costals  of  the  first  pair.  On  the  inner  surface 
of  each  is  a  sutural  scar  for  articulation  with  the  axillary  buttress.  This  is  5  mm.  wide  and  on 
one  of  the  pieces  it  is  17  mm.  long,  while  the  original  length  has  been  still  greater.  On  page 
143  of  his  Vertebrata  of  the  Tertiary  Formations  of  the  West,  Cope  refers  to  certain  bones 
which  he  had  formerly  described  as  xiphiplastrals  and  as  showing  that  the  pubis  had  articulated 
with  the  plastron.  With  this  lot  of  bones  is  a  rough  drawing  made  by  Cope  which  represents 
one  of  these  costals  as  a  part  of  the  plastron.  The  bone  (fig.  384)  is,  however,  without  doubt 
a  costal,  as  Cope  himself  came  to  suspect.  The  outside  of  this  costal  shows  strong  concentric 
grooves  produced  during  the  growth  of  the  first  costal  scute. 

With  the  bones  just  described  is  what  appears  to  be  one  of  the  hinder  neurals.  It  is  16 
mm.  long,  17  mm.  wide,  and  7  mm.  thick.  The  outer  surface  is  rather  rough.  A  fragment  of 
the  plastron,  probably  about  its  center,  is  9  mm.  thick.  The  right  free  border  of  the  hypo- 
plastron  is  represented  by  a  fragment  23  mm.  long.  The  edge  is  subacute.  From  this  the  bone 
thickens  rapidly  to  the  inner  border  of  the  beveled  surface  on  the  upper  side,  where  it  is  9.5 
mm.  thick.    This  surface  is  15  mm.  wide  and  is  bounded  interiorly  by  a  sharp  groove. 


386^. 


384. 
Figs.  384-386. — Echmatemys  testudinea.     Costal  and  plastral  bones. 

384.  Distal  end  of  right  first  costal,  inner  surface.    X2.    No.  1181  A.M.N.  H.     Shows  scar  for  axillary  buttress. 

385.  Mesial  portion  of  right  hyoplastron.    Xi-    No.  1179  A.  M.N.H. 

386.  Free  border  of  hypoplastron,  with  section  (a)  at  articulation  with  xiphiplastron.    Xj.    No.  1 179  A.  M.  N.  H. 

No.  1179  may  or  may  not  all  belong  to  the  same  individual,  and  the  bones  are  probably 
another  portion  of  Cope's  principal  specimen.  The  right  hyoplastron  (fig.  385)  measures  on 
the  midline  46  mm.  At  the  midline  and  where  it  joined  the  hypoplastrals  the  thickness  is  13 
mm.,  and  12  mm.  where  it  joined  the  entoplastral.  The  femoro-abdominal  sulcus  crosses  33 
mm.  behind  the  entoplastron.  The  humero-pectoral  sulcus  can  not  be  distinguisht.  A  frag- 
ment of  the  epiplastron  has  the  free  edge  rather  acute.  The  beveled  surface  is  16  mm.  wide 
and  has  a  maximum  thickness  of  9  mm.  Fig.  386  represents  the  upper  surface  of  the  left  free 
border  of  the  hypoplastron  and  a  section  at  the  hypoxiphiplastral  suture.  The  beveled  area 
has  a  width  of  about  20  mm.  and  at  the  summit  the  bone  is  13  mm.  thick.  It  is  limited  on  the 
inner  side  by  a  sharp  groove.  The  beveled  surface  shows  grooves  produced  by  the  scute — the 
femoral.  A  fragment  of  the  left  xiphiplastron  shows  that  this  was  only  36  mm.  long  on  the 
midline.  There  was  evidently  a  posterior  notch.  At  the  anterior  end  of  the  median  suture  the 
thickness  of  the  bone  is  8  mm.;  posteriorly  it  thins  down  to  4  mm. 

No.  1179  includes  likewise  the  proximal  half  of  a  costal,  almost  certainly  the  sixth  of  the 
left  side  (plate  45,  fig.  17).  The  upper  surface  presents  an  elevation  outside  of  the  costo- 
vertebral sulcus,  as  in  the  case  of  those  previously  mentioned.  Anteriorly  this  sulcus  is  removed 
6  mm.  from  the  neural  border,  but  posteriorly  it  has  receded  to  a  distance  of  13  mm.  This 
indicates  that  the  fourth  vertebral  expanded  where  the  sulcus  down  the  sixth  costal  departed. 


emydidjI.  305 

The  posterior  border  of  the  bone  is  5  mm.  thick,  while  the  anterior  sutural  border  is  8  mm. 
thick.  This  is  due  evidently  to  the  formation  of  a  ridge  on  the  fifth  and  sixth  costals  for  the 
reception  of  the  inguinal  buttress. 

No.  1 173  of  the  American  Museum  forms  Cope's  third  specimen.  There  is  present  a 
portion  of  the  first  costal  with  the  articular  surface  for  the  axillary  buttress.  There  is  a  rough 
drawing  by  Cope  on  which  this  bone  is  traced  as  belonging  to  the  xiphiplastrals.  This  bone 
belonged  to  a  much  larger  individual  than  that  represented  by  No.  1181,  but  the  scar  for  the 
buttress  is  no  longer.  This  costal  was  at  least  35  mm.  wide  and  is  7  mm.  thick  where  it  joined 
the  first  and  second  peripherals.  The  outer  surface  is  smooth.  With  this  lot  is  a  portion  of  the 
third  right  peripheral,  excavated  at  the  hinder  end  to  form  a  part  of  the  sternal  chamber.  Fig. 
387  represents  the  sutural  surface  which  articulated  with  the  second  peripheral.  It  will  be 
seen  that  the  free  border  is  broadly  rounded.  Fig.  388  presents  the  outlines  and  a  view  of 
the  anterior  articular  surface  of  a  hinder  free  peripheral.  This  is  recurved  and  has  an  acute 
edge.    The  surface  is  uneven;   and  the  sulci  are  narrow  but  sharply  imprest. 

No.  1258  appears  to  represent  another  portion  of  Cope's  principal  specimen.  Among  the 
bones  is  an  entoplastron,  but  not  the  one  described  by  Cope.  The  one  which  furnisht  Professor 
Cope's  figure  12  is  not  one-half  the  size  of  nature,  as  stated,  but  four-sevenths.  The  breadth  of 
the  entoplastron  of  No.  1258  is  37  mm.,  its  antero-posterior  extent  24  mm.,  2  mm.  less  than 
that  given  by  Cope.  The  longitudinal  sulcus  is  very  obscure,  while  the  humero-pectoral 
plainly  crosses  the  bone  about  the  middle  of  the  length.  The  internal  face  of  the  bone  is  badly 
weathered,  so  that  little  regarding  the  position  of  the  bone  can  be  determined  therefrom. 
The  anterior  border  is  damaged  for  most  of  its  extent.  There  is  a  piece  of  the  left  hyoplastron 
present,  but  it  is  impossible  to  say  whether  the  two  bones  belong  together.  What  appears  to  be 
the  free  border  of  the  right  hyoplastron  is  present.    The  edges  are  acute.    The  beveled  surface 

on  the  upper  side  attains  a  width  of  15  mm.  and  a 
thickness  of  9  mm.  Two  portions  of  the  epiplastra 
are  present,  but  their  proper  positions  are  difficult  to 
determine.  They  are  acute-edged  and  they  thicken 
rapidly,  the  beveled  surface  attaining  a  thickness  of 
II  mm.  and  a  width  of  14  mm.  At  the  inner  border 
the  thickness  is  diminisht  suddenly, 
o  go  The  fragment  of  the  hinder  lobe  figured  by  Cope 

(his  fig.  13)  appears  to  indicate  the  presence  of  a 
Figs.  387  and  ^^S.—Echmatemys  testu-     well-developt  inguinal  buttress,  whose  base  extended 

f  "a^\t  u'P  ^'-  •  "7^      inward  about  20  mm.  from  the  free  border.    At  the 

A.  M.  N.  H.  ,  11  J     •  1  •   1  u 

suture  between  hypoplastron   and  xiphiplastron    the 

387.  Section  at  anteriorend  of  third  right  peripheral,     beveled  upper  border  has  a  width  of  15  mm.  and  here 

■588.  Hinder  peripheral.    Section  to  show  thickness       »u     u  •     o  -        ..U"    1        n-l.      '  U      J  f  »U 

and  curvature.  '■"^  bone  IS  8.5  mm.  thick.     1  he  inner  border  ot  the 

beveled  surface  is  bounded  by  a  considerable  groove. 
The  free  border  is  acute.  The  lower  surface  of  this  hinder  lobe  was  flat  transversely  and 
turned  up  posteriorly.  The  abdomino-femoral  sulcus  crost  the  plastron  somewhat  in  front  of 
the  inguinal  notch. 

Cope  believed  there  was  an  undivided  intergular,  but  the  writer  finds  nothing  to  sustain 
this  opinion,  and  it  is  improbable.  Undoubtedly  the  species  is  an  emyd,  and  the  presence  of 
an  intergular,  single  or  divided,  would  probably  be  unique.  The  proximal  end  of  a  costal,  the 
second  or  the  fourth  of  the  left  side,  has  a  width  of  20  mm.  and  a  thickness  of  8.5  mm.  The 
longitudinal  sulcus  traverst  the  bone  at  a  distance  of  7  mm.  from  the  neural  border,  showing 
again  that  the  vertebral  scutes  were  very  narrow.  While  the  surface  is  uneven,  there  is  no 
swelling  outside  of  the  sulcus,  differing  thus  from  the  others  described. 

Echmatemys  euthneta  (Cope). 
Plate  46,  fig.  I ;  text-figs.  389-391. 

Emys  euthnetus,  CoPE,  Sixth  Ann.  Report  U.  S.  Gaol.  Surv.  Terrs.,  1872  (1873),  p.  628. 
Emys  euthneta,  CoPE,  Vert.   Tert.   Form.  West,  1884,  pp.   129,  133,  plate  xviii,  figs.  34-42- — Hay, 
Bibliog.  and  Cat.  Foss.  Vert.,  1902,  p.  447. 
20 


^ 


306  KOSSIL    TURTLES    OK    NORTH    AMHRICA. 

This  is  one  of  the  two  species  of  emyd  turtles  described  by  Professor  Cope  from  the  Green 
River  beds  in  the  region  of  Black  Buttes,  the  other  species  being  E.  megaulax.  Emys  euthneta 
is  said  to  have  been  represented  by  numerous  specimens  and  to  have  been  abundant  in  the 
red  beds  which  lie  between  those  identified  as  belonging  to  the  Green  River  and  the  Bridger 
epochs  at  Black  Buttes.  The  figured  bones  of  the  species  are  in  the  National  Museum  at 
Washington.     They  have  the  catalog  number  4125. 

In  the  American  Museum  there  are  three  lots,  parts  ot  the  Cope  collection,  which  appear 
to  belong  to  this  species.  The  parts  which  were  figured  by  Cope  were  3  neurals,  4  peripherals. 
I  epiplastron,  and  a  part  of  1  xiphiplastron.  All  these,  it  is  stated,  were  found  together  and 
were  supposed  to  belong  to  a  single  individual.  The  neurals  displayed  no  dorsal  keel,  the 
scutal  sulci  were  not  deeply  imprest,  and  the  surfaces  of  the  carapacial  bones  were  smooth. 
The  length  of  the  carapace  of  this  individual  must  have  been  about  190  mm.,  the  three  neurals 
taken  together  measuring  49  mm.  One  neural,  probably  the  third  (Cope's  fig.  34),  had  a 
length  of  19  mm.  and  a  width  of  15.5  mm.,  and  a  thickness  of  4  mm.  The  neurals  were  not  so 
wide  in  proportion  to  their  length  as  in  E.  megaulax.  The  peripherals  resemble  those  of  £. 
megaulax,  but  they  were  not  so  deeply  imprest  by  the  sulci.  The  peripheral  represented  by 
Cope's  fig.  37  is  apparently  an  anterior  second.  It  is  8  mm.  thick  where  it  joined  the  third. 
Cope's  fig.  38  appears  to  represent  the  ninth  peripheral  of  the  right  side,  while  his  fig.  40  shows 
probably  the  eighth  of  the  left  side.  The  border  which  articulated  with  the  seventh  is  7  mm. 
thick;  that  which  articulated  with  the  ninth  is  6  mm.  thick.  Cope's  figure  of  the  epiplastron 
shows  correctly  that  the  lip  projected  abruptly  for  a  short  distance,  and  was  little,  if  at  all, 
notcht  at  the  midline.  It  is  rounded  off  both  above  and  below  and  has  the  free  border  obtuse. 
Its  greatest  thickness  is  6  mm.  It  is  doubtful  how  near  the  midline  the  fragment  approacht, 
so  that  the  width  of  the  lip  is  uncertain.  The  hinder  lobe  is  broadly  notcht  and  the  beveled 
surface  on  the  upper  side  is  relatively  narrow.  The  thickness  of  the  border  is  5  mm.  anteriorly. 
Here  the  free  edge  is- obtuse  but  posteriorly  it  becomes  acute. 

In  the  Cope  collection  of  fossil  reptiles,  in  the  American  Museum  of  Natural  History, 
there  are  four  lots  of  bones  which  are  labeled  by  Cope  as  having  come  from  the  "red  beds" 
of  Black  Buttes  and  were  regarded  by  him  as  belonging  to  his  Emys  euthneta.  These  bear  the 
catalog  numbers  1 1 19,  1174,  1176,  and  1 182.  Nos.  1 176  and  1 182  together  present  nearly 
the  whole  of  the  plastron,  except  the  epiplastron  and  the  entoplastron.  No.  1182  furnishes 
most  of  the  hyoplastron  of  the  right  side  and  most  of  the  hypoplastron  of  the  left  side.  These 
bones  are  relatively  thin. 

The  plastron  had  a  total  length  of  nearly  240  mm.  At  the  crossing  of  the  median  longi- 
tudinal suture  and  the  hyohypoplastral  suture  the  thickness  is  7  mm.  On  account  of  some 
missing  fragments,  the  length  of  the  hyoplastron  can  not  be  exactly  determined.  The  anterior 
lobe  has  a  width  of  about  120  mm.  The  free  border  of  the  epiplastral  process  is  acute,  but 
soon  the  bone  thickens  to  8  mm.  At  the  hyoepiplastral  suture  the  beveled  surface  on  the  upper 
side  is  10  mm.  wide.  No  groove  separates  it  from  the  surface  beyond.  The  humero-pectoral 
sulcus,  deeply  sunken,  crosses  the  free  border  of  the  bone  14  mm.  behind  the  suture  just 
mentioned.  It  appears  almost  certain  that  this  sulcus  did  not  touch  the  entoplastron.  A 
deeply  imprest  sulcus  cut  off  an  axillary  scute,  only  a  part  of  which  was  situated  on  the  hyo- 
plastron. The  pectoro-abdominal  sulcus  crosses  the  bone  at  a  distance  of  19  mm.  in  front  of 
the  hyohypoplastral  suture,  measured  at  the  midline;  measured  at  the  free  border  of  the  bone 
the  distance  is  30  mm.  This  sulcus  is  narrow  and  shallow.  On  the  upper  side  of  the  bone, 
on  the  outer  two-fifths,  a  strong  axillary  buttress  arises  for  articulation  with  the  first  costal. 

The  hypoplastron  has  a  length  of  70  mm.  The  width  of  the  hinder  lobe  was  close  to  105 
mm.  The  free  border  has  an  acute  edge.  The  superior  beveled  surface  has  a  width  of  10  mm. 
at  the  hypoxiphiplastral  suture.  No  groove  intervenes  between  this  surface  and  that  beyond. 
At  a  distance  of  20  mm.  from  the  free  border  the  thickness  of  the  bone  is  8  mm.  The  inguinal 
buttress  rises  from  the  upper  surface  of  this  bone  at  a  line  less  than  half  the  distance  from 
the  free  border  to  the  midline.  The  abdominal  scutes  of  this  individual  had  a  length  of  about 
58  mm.  A  fragment  of  the  first  costal  (fig.  389)  shows  that  the  axillary  buttress  of  this  turtle 
ascended  a  distance  of  20  mm.  on  the  inner  surface  of  the  costal. 

Specimen  No.  1176  (plate  46,  fig.  i)  presents  the  nearly  complete  hypoplastron  and  the 
complete  xiphiplastron.     The  individual  was  only  slightly  smaller  than  the  preceding,  the 


KMYIMD^:. 


307 


hypoplastron  having  a  length  of  73  mm.  The  superior  beveled  border  is  12  mm.  wide.  At  the 
inner  border  of  this  surface  the  bone  is  12  mm.  thick.  Beyond  the  bevel  the  bone  thins  some- 
what. Near  the  hypoxiphiplastral  suture  a  groove  develops  just  inside  the  beveled  surface. 
On  the  lower  surface  of  the  bone  is  seen  the  broad  and  deeply  sunken  abdomino-femoral 
sulcus,  which  crosses  at  a  distance  of  40  mm.  behind  the  anterior  border  of  the  bone.  The 
median  longitudinal  sulcus  also  has  been  broad  and  deep.  There  has  been  a  large  inguinal 
scute,  part  of  which  lay  on  the  hypoplastron. 

The  xiphiplastron  has  a  length  of  44  mm.  on  the  midline.  Posteriorly  there  was  a  notch 
about  35  mm.  wide  and  10  mm.  deep.  The  superior  beveled  surface  (fig.  390,  upper  view  and 
section  at  hypoxiphiplastral  suture)  is  separated  from  that  beyond  it  by  a  sharp  groove.  The 
greatest  thickness  of  the  bone,  1 1  mm.,  is  at  the  summit  of  the  bevel,  but  for  some  distance 
it  diminishes  little.  At  the  midline  it  has  become  reduced  to  about  7  mm.  The  femoral 
scutes  measured  50  mm.  along  the  midline;  the  anals,  25  mm.  The  femoro-anal  sulci  are 
deep  and  wide. 

No.  1 1 19  furnishes,  together  with  unimportant  parts,  a  portion  of  the  epipJastron, 
including  the  lip.     Seen  from  above,  it  resembles  greatly  the  one  figured  by  Cope  (his  plate 


39'- 


Figs.  389-391. — Echmutetnys  cuthnetii.     Costal  and  plastral  bones. 

389.  Inner  surface  of  right  first  costal.      X  '.     Specimen  in  A.  M.  N.  H.     Shows  scar  for  axillary  buttress. 

390.  Portion  of  hinder  lobe,  upper  surface,  with  section  of  free  border.     Xi.     No.  1176  A.  M.  N.  H. 

391.  Restoration  of  plastron.    Mostly  from  Nos.  1 176  and  1182  A.  M.  N.  H. 

xviii,  fig.  410).  Seen  from  below,  it  is  observed  that  the  gular  scutes  could  have  extended 
backward  hardly  more  than  half-way  to  the  entoplastron.  The  lip  must  have  been  at  least 
22  mm.  wide.  The  whole  free  border  of  the  bone  was  obtuse.  The  superior  horn-covered 
surface  is  convex.  Laterally  the  upper  surface  of  the  lip  is  swollen,  and  is  about  7.5  mm.  thick; 
but  at  the  midline  the  thickness  is  reduced  to  4  mm.  The  individual  was  a  smaller  one  than 
either  of  those  just  described.  A  fragment  of  a  fifth  or  sixth  costal  is  thickened  on  one  side  for 
articulation  with  the  sixth  or  fifth  costal  and  has  an  articular  surface  for  the  inguinal  buttress. 
A  peripheral  and  some  fragments  of  costals  show  that  the  sulci  were  rather  deeply  imprest. 

Lot  No.  1 174  contains  many  fragments  of  more  than  one  individual,  possibly  of  more  than 
a  single  species.  Fragments  of  the  fifth  and  sixth  costals  appear  to  indicate  that  the  inguinal 
buttresses  were  articulated  principally  with  the  sixth  costal. 

Fig.  391  presents  a  restoration  of  the  plastron  from  the  various  bones  described.  The 
epiplastral  lip  is  taken  from  Cope's  figure. 

After  the  preceding  descriptions  and  figures  had  been  prepared  3  additional  specimens  of 
this  species  arrived  at  the  American  Museum  of  Natural  History.  These  were  collected  in 
1906  by  the  museum's  expedition  sent  into  the  deposits  of  the  Wasatch  in  Wyoming.  They 
were  all  obtained  on  Bitter  Creek,  within  about  20  miles  of  Black  Buttes,  where  Cope  obtained 


3o8 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


Vertebral. 

No.  6031. 

No.  6042. 

Length. 

Width. 

Length. 

Width. 

4* 
41 
47  ± 
40 
45 

53 
38 
4»± 
49 

55 

51 
48 
50 
47 
49 

63 
40 
39 
49 

68 

his  specimens.  One  of  the  new  specimens,  No.  6032,  215  mm.  long  and  175  mm.  wide, 
furnishes  the  shell  complete,  with  the  exception  of  the  proximal  ends  of  some  of  the  median 
costals  and  parts  of  two  neurals.  No.  6042,  270  mm.  long  and  227  mm.  wide,  furnishes  a 
complete  shell,  but  has  the  carapace  crusht  down  on  the  plastron.  No.  6043,  somewhat  smaller 
than  No.  6032,  is  a  nearly  complete  shell,  lacking  only  a  part  of  the  rear  of  the  carapace  and 
the  hinder  extremity  of  each  xiphiplastron. 

In  No.  6032  the  third  neural  is  octagonal,  whereas  in  No.  6042  it  is  hexagonal.  In  both 
specimens  the  fifth  is  octagonal,  the  hinder  angles  being  in  contact  with  the  sixth  costals.  In 
No.  6032  the  sulci  bounding  the  vertebral  scutes  are  deeply  sunken,  and  in  many  places  these 

sulci  are  bordered  by  crimpt  ridges.  In  No. 
6043  also,  all  of  the  sulci  are  deeply  sunken  and 
included  between  ridges  of  the  bone. 

The  vertebral  scutes  have  their  sides  more 
or  less  bracket-shaped.  The  dimensions  of 
those  of  Nos.  6032  and  6042  are  given  in  the 
accompanying  table. 

The  anterior  lobe  of  No.  6032  is  52  mm. 
long  and  96  mm.  wide  at  the  base.  The  epi- 
plastral  lip  is  40  mm.  wide.  Its  anterior  border 
is  excavated  somewhat,  but  in  the  other  specimens  it  is  truncated.  The  upper  surface  of  the 
lip  is  concave  from  side  to  side.  The  horn-covered  areas  of  the  upper  surface  of  this  lobe  are 
narrow.  In  all  the  specimens  the  entoplastron  is  wider  than  long.  It  is  not  crost  by  the 
humero-pectoral  sulcus,  altho  in  No.  6042  this  sulcus  skirts  its  posterior  border.  The  bridge 
of  No.  6032  is  80  mm.  wide.  The  hinder  lobe  has  a  length  of  68  mm.  and  a  width  of  94  mm. 
at  the  base.    The  notch  in  the  rear  is  large,  45  mm.  wide  and  17  mm.  deep. 

No.  6043  presents  the  interior  surfaces  of  carapace  and  plastron.  The  bases  of  the  axillary 
and  the  inguinal  buttresses  extend  inward  only  about  a  third  of  the  distance  from  the  free 
borders  of  the  lobes  to  the  midline.  Each  axillary  buttress  rises  to  a  point  about  one-third  the 
distance  from  the  lower  end  of  the  first  costal  to  the  midline  of  the  first  neural.  The  inguinal 
buttresses  are  applied  against  the  contiguous  borders  of  the  fifth  and  sixth  costals  and  rise  half- 
way to  the  midline  of  the  carapace. 

Echmatemys  wyomingensis  (Leidy). 
Plate  47,  fig.  i;   text-figs.  392-403. 

Emys  wyomingensis,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1869,  p.  66;   Ann.  Report  U.  S.  Geol.  Surv. 

Montana,  etc.,  1871  (1872),  p.  367;  Contrib.  Ext.  Fauna  West.  Terrs.,  1873,  p.  140,  plate  ix,  fig.  5; 

plate  x,  figs.  I,  2. — Cope,  Ann.  Report.  U.  S.  Geol.  Surv.  Terrs.,  1872  (1873),  p.  626. — Osborn, 

ScoiT  and  Speir,  Contrib.  Mus.  Geol.  and  Arch.  Princeton  Coll.,  No.  i,  1878,  p.  95. — Hay,  Bibliog. 

and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  448. 
Emys  jeanesi,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1870,  p.  123;  Ann.  Report  U.  S.  Geol.  Surv.  Wyoming, 

etc.,  1870  (1871),  p.  366. 
Emys  jeanesianus,  Leidy,  Amer.  Jour.  Sci.  (3),  11,  1871,  p.  372. 
Emys  vyomingensis,  CoPE,  Wheeler's  Surv.  W.  looth  Merid.,  iv,  1877,  p.  53;  Vert.  Tert.  Form.  West, 

1884,  p.  135,  plate  xxiii,  figs.  9-II. 
Chrysemys  wyomingensis,  Hay,  Amer.  Jour.  Sci.,  xvill,  1904,  p.  267,  plate  xiv,  text-figs.  3,  4. 

The  present  species  was  based  by  Dr.  Leidy  on  an  isolated  left  epiplastral  bone  which  had 
been  sent  to  him  by  Dr.  J.  Van  A.  Carter  and  which  had  been  obtained  from  the  Bridger  beds 
somewhere  in  the  vicinity  of  Fort  Bridger,  Wyoming.  This  bone  is  now  in  the  collection  of 
the  Academy  at  Philadelphia.  It  shows  that  the  epiplastral  lip,  from  one  gulo-humeral  sulcus 
to  the  other,  had  a  width  of  60  mm.  The  anterior  border  is  truncated,  with  a  slight  notch 
mesiad  of  the  sulcus  named,  so  that  a  blunt  tooth  is  suggested.  The  whole  free  border  is  acute, 
least  so  just  outside  the  sulcus.  The  median  sulcus  on  the  lower  side  apparently  deviated 
slightly  from  the  midline,  and  this  caused  Leidy  to  suppose  that  there  had  been  present  a 
narrow  intergular  scute.  The  thickness  of  the  bone  at  the  midline  is  I2  mm.,  and  the  same 
behind  each  of  the  lateral  teeth.  On  the  upper  surface  there  is  a  broad  low  ridge  running  along 
the  midline  and  on  each  side  of  this  ridge  a  broad  shallow  groove.    On  this  surface  the  gulo- 


EMYDID^. 


309 


humeral  sulci  run  directly  backward.  The  hone  is  thickened  backward  a  distance  of  20  mm. 
The  horn-covered  band  is  17  mm.  wide  at  the  hyoepiplastral  suture. 

In  1870,  as  cited  above,  Dr.  Leidy  described  his  Emys  jeanesi  from  a  quite  complete  shell 
found  near  Fort  Bridger.  In  1873  he  referred  this  specimen  to  his  earlier  E.  wyomingensis. 
An  examination  shows  that  its  epiplastron  is  as  nearly  like  that  forming  the  type  of  £.  wyoming- 
ensis as  could  be  expected  in  two  individuals  of  the  same  species.  The  width  of  that  of  E. 
jeanesi  is  ^4.  mm.;  the  thickness  at  the  midline,  1 1  mm.;  behind  the  lateral  teeth,  12  mm.  As 
in  the  type  of  E.  wyomingensis,  there  is,  on  the  upper  surface,  a  broad  longitudinal  ridge 
flankt  by  broad  grooves.  The  thickening  of  the  upper  surface  extends  backward  about  20  mm. 
The  width  of  the  smooth  band,  at  the  hyoepiplastral  suture,  is  13  mm.  There  appears  to  be 
neither  reason  nor  profit  in  regarding  E.  jeanesi  as  distinct  specifically  from  E.  wyomingensis. 

The  type  of  E.  jeanesi  was  figured  by  Leidy.  Diagrammatic  figures  are  here  presented 
of  both  carapace  (fig.  392)  and  plastron  (fig.  393). 

An  examination  of  the  interior  of  the  shell  of  this  type  shows  that  the  inguinal  buttresses 
were  not  so  strongly  developt  as  in  most  other  species  of  Echmatemys.     They  arise  from  the 


392- 


Figs.  392  and  393. — Echmatemys  wyomingensis.     Carapace  and  plastron  of  type  of 
Emys  jeanesi.      X\.     U.  S.  N.  M. 

392.  Carapace.  393.  Plastron. 

floor  of  the  plastron  at  a  line  two-fifths  the  distance  from  the  free  border  of  the  hinder  lobe  to 
the  midline.  The  distances  are  respectively  29  mm.  and  69  mm.  The  width  of  the  smooth 
band,  on  the  upper  surface,  at  the  hypoxiphiplastral  suture,  is  12  mm.  The  greatest  thickness 
of  the  bone  here  is  13  mm.  The  axillary  scute  is  mostly  missing,  but  it  appears  to  have 
extended  backward  only  to  the  middle  of  the  fourth  marginal.  The  inguinal  scute  too  is 
short,  reaching  forward  only  to  the  middle  of  the  seventh  marginal. 

No.  5988  of  the  American  Museum  furnishes  the  plastron  complete  and  the  carapace 
lacking  peripherals  3  to  6  inclusive,  of  the  right  side,  the  distal  ends  of  the  4  posterior  costals 
of  the  same  side,  and  the  pygal.  The  specimen  was  obtained  in  1903,  on  Little  Dry  Creek, 
Wyoming,  and  belongs  to  horizon  B.  The  shell  has  been  crusht  downward  after  burial  and 
the  width  considerably  exaggerated.  Both  eleventh  peripherals  are  present,  but  they  stand 
apart  about  90  mm.,  whereas  in  life  they  were  separated  only  by  a  pygal  about  20  mm.  wide. 

The  surface  of  the  shell  was  smooth.  There  is  no  suggestion  of  a  median  keel.  The  length 
of  the  carapace  (text-fig.  394)  was  close  to  335  mm.    The  width  may  be  regarded  as  having 


FOSSIL    TURTLES    OF    NOR'IH    AMKRICA. 


been  about  250  mm.  The  anterior  border  is  truncated.  The  free  margins  are  nowhere 
notcht.  The  nuchal  is  50  mm.  long,  43  mm.  wide  in  front,  and  75  mm.  where  widest.  Its 
anterior  border,  as  well  as  that  ot  the  peripherals  ot  the  first  pair,  is  acute.  These  bones  are 
rather  thin,  only  1 1  mm.  The  anterior  and  the  posterior  neurals  are  relatively  broad,  the 
others  narrow.    The  dimensions  of  the  neurals  are  shown  in  the  table. 


Dimensions  of  tht 

neurals. 

No. 

Length. 

Width. 

I 

42 

30 

2 

34 

35 

3 

38-5 

18 

4 

35 

»7 

5 

35 

33 

6 

z6 

30-5 

7 

18 

34 

8 

28 

28 

Dimensions  of  peripherals. 
No.        Height 


Dimensions  of  vertebral  scutes. 


3« 
39 
4» 
46 

50 


Width  free 
border. 


43 
45 
45 
39 
40 


Width  cos- 
tal border. 


^5 
17 
»7 
37 
33 


No. 

I 

z 
3 
4 
5 


Length. 


64 
68 

74 


Width 
in  front. 


75 
49 
37 
44 
35 


Greatest 
width. 

78 
56 
53 
66 
9o± 


The  fifth  neural  is  octagonal,  due  doubtless  to  an  individual  variation.  The  first  supra- 
pygal  is  22  mm.  long  and  ^^  mm.  wide. 

The  costal  plates  are  usually  about  as  wide  at  the  upper  end  as  at  the  distal  end.  However, 
the  third  is  ^j  mm.  wide  proximallv  and  27  mm.  distally.    The  third  has  a  height  equal  to  only 


394- 


395- 


Figs.  394  and  ^95. — Echmatemvs  wyomingensis.     Carapace  and  plastron.     X  J. 

No.  5988  A.  M.N.  H. 

394.  Carapace.  395.  Plastron. 

41  per  cent,  of  the  height  of  the  first  costal  near  its  hinder  border.  The  posterior  peripherals 
possess  an  acute  free  border.    The  first  costal  bone  is  hardly  two-thirds  as  wide  as  high. 

The  dimensions  of  the  peripherals  are  given  in  the  table  above. 

The  sulci  are  narrow  and  rather  shallow.  The  first  and  fifth  vertebral  scutes  are  broad, 
the  others  are  narrow,  with  nearly  parallel  sides.  The  dimensions  of  the  vertebral  scutes 
are  shown  in  tabular  form  above. 

The  costo-marginal  sulci  run  about  i6  mm.  below  the  costo-peripheral  sutures. 

The  plastron  (plate  47,  fig.  I ;  text-fig.  395)  is  304  mm.  long.  It  is  thick,  especially  at  the 
crossing  of  the  longitudinal  and  the  hyohypoplastral  sutures.    The  length  of  the  anterior  lobe 


kmydida;. 


311 


is  82  mm.;  the  width,  143  mm.  Thus  the  length  is  only  55  per  cent,  of  the  width.  The  epi- 
plastral  lip  is  55  mm.  wide  and  projects  but  little  beyond  the  general  curve  of  the  lobe.  The 
beveled  surface  on  each  side  of  the  lip  (fig.  396)  on  the  upper  surface  of  the  bone  is  only-i5  mm. 
wide  and  at  the  hyoepiplastral  suture  only  12  mm.  The  thickened  portion  of  the  epiplastrals 
above  the  lip  extends  backward  only  16  mm.,  and  where  thickest,  just  mesiad  of  the  gular 
sulci,  only  15  mm.  The  free  borders  of  the  lobe  are  acute  nearly  to  the  lip.  The  entoplastron 
is  lozenge-shaped,  51  mm.  long  and  65  mm.  wide.    The  bridge  is  133  mm.  wide. 

The  posterior  lobe  is  98  mm.  long  and  135  mm.  wide,  the  length  being  thus  about  73  per 
cent,  of  the  width.  The  width  is  considerably  less  than  the  half  of  the  length  of  the  plastron. 
In  the  type  of  ii.  jeanest  the  width  is  close  to  half  the  plastral  length.  Posteriorly  in  No.  5988 
there  is  a  broad  notch.    The  beveled  surfaces  along  the  borders  on  the  upper  side  (fig.  397) 

396.  400. 


.^98. 


399.  397.  401. 

tlGS.  396-401. — Erhmniem\s  Wfomiii^cnsis.     Variou.s  bones. 

396.  Upper  surface  of  rpiplastral  lip.    Xl.    No.  5988  A.  .\J.  N.  H. 

397.  Upper  surface  of  right  side  of  hinder  lobe  of  plastron.     X  J-     No.  5988  A.  M.  N.  H. 

398.  Left  dcntari,'  bone,  outer  surface.     X?.     No.  5968  A.  M.  N.  H. 

399.  Same  dentarv  as  fig.  398,  seen  from  above.     X^. 

400.  Upper  surface  of  anterior  lobe.     Xj.    No.  6010  A.M.  N.  H. 

401.  Upper  surface  of  free  border  of  hinder  lobe  of  plastron.     X^.    No.  6010  .\.  M.  N.  H. 

have  a  width  of  i8  mm.  at  the  hypoxiphiplastral  sutures.  Here  the  thickness  of  the  bones  is 
14  mm. 

The  gular  scutes  are  39  mm.  long;  the  humerals,  36  mm.;  the  pectorals,  51  mm.;  the 
abdominals,  84  mm.;  the  femorals,  58  mm.;  the  anals,  37  mm.;  all  measured  along  the  mid- 
line. The  axillary  scute  falls  far  short  of  reaching  back  to  the  fifth  marginal;  the  inguinal 
comes  forward  nearly  to  the  sixth  marginal. 

The  posterior  buttresses  extend  inward  from  the  free  borders  of  the  hinder  lobe  little  more 
than  one-third  the  distance  to  the  midline.  Articulating  with  the  fifth  and  sixth  costals,  they 
rise  about  44  mm.,  to  a  point  nearly  half-wav  from  the  lower  border  of  these  costals  to  the 
bases  of  the  rib-heads.  The  anterior  buttresses  appear  to  have  risen  about  20  mm.  within  the 
first  costals. 


312 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


No.  5987  of  the  American  Museum  is  referred  to  this  species,  altho  it  presents  some  impor- 
tant differences.  It  is  represented  by  a  damaged  shell  from  Grizzly  Buttes.  Its  size  is  almost 
exactly  that  of  No.  5988.  The  carapace  differs  especially  in  having  the 
costals  modified  so  that  their  distal  ends  are  alternately  wider  and  nar- 
rower. The  proximal  ends  are  not  present.  The  dimensions  of  the  costals 
are  shown  in  the  table  herewith. 

The  plastron  is  thick  and  heavy,  the  thickness  of  the  bones  at  the 
crossing  of  the  longitudinal  median  suture  with  that^between  the  hypo- 
plastra  and  xiphiplastra  being  18  mm.  The  anterior^lobe  has  the  same 
proportions  as  in  No.  5988,  but  its  width  is  slightly  greater.  The  thick- 
ening on  the  upper  side  of  the  lip  extends  back  22  mm.,  thus  being  wider 
than  in  No.  5588,  but  the  lip  above  and  below  resembles  closely  that  of 
the  type  of  Emys  jeanesi.  The  hinder  lobe  is  wider  than  in  No.  5588, 
being  150  mm.  The  beveled  surface  on  the  upper  side  of  the  lobe  has  a  width,  at  the  hypo- 
xiphiplastral  suture,  of  26  mm.     The  inguinal  scute[|runs^for  'a  short_[distance  between  the 


Costal. 

Width  of 
distal  end. 

4> 

zo 

4' 

Z7 

38 

7 

34 

8 

Z7 

403- 


X}. 


Figs.  402  AND  403. — Echmatemys  wyomtngensis.     Carapace  and  plastron. 
Yale  University   Museum. 

40Z.  Carapace  showing  supernumerary  neurals,  costals,  etc.  403.  Plastron. 

abdominal  scute  and  the  sixth  marginal.  It  is  possible  that  in  this  specimen  we  have  a  dis- 
tinct species,  but  the  differences  are  probably  due  to  individual  variations. 

No.  5950  of  the  American  Museum,  collected  in  1903,  at  Grizzly  Buttes,  Wyoming,  pre- 
sents a  portion  of  both  carapace  and  plastron,  both  badly  crusht.  The  specimen  is  peculiar 
in  the  form  of  the  first  vertebral  scute.  This  is  longer  than  in  No.  5988  and  much  narrower  in 
front.  The  length  is  77  mm. ;  the  width  in  front,  60  mm.  The  lateral  sulci  bounding  this  scute 
meet  the  first  marginals  at  the  middle  of  the  length  of  the  latter. 

No.  5968  of  the  American  Museum  was  collected  in  the  western  portion  of  Grizzly  Buttes. 
It  furnishes  a  good  plastron,  various  fragments  of  the  carapace,  some  limb  bones,  and  the  right 
dentary.  The  plastron  has  a  total  length  of  306  mm.  The  specimen  is  valuable  on  account 
of  the  dentary  bone.  It  establishes  the  fact  that  the  triturating  surfaces  of  the  jaws  were 
smooth  and  very  narrow.  Fig.  398  represents  the  left  dentary  as  seen  from  the  side  and  fig. 
399  as  seen  from  above;  both  of  the  natural  size.  A  little  of  the  bone  at  both  extremities  of  this 
dentary  is  missing.    The  portion  remaining  is  24  mm.  long.    The  triturating  surface  is  hardly 


EMYDID^. 


3»3 


3  mm.  wide,  and  it  is  transversely  concave.  In  the  figure  this  surface  is  shaded  by  horizontal 
lines.    The  height  of  the  bone  is  7  mm.  and  the  thickness  nowhere  exceeds  3.5  mm. 

The  right  humerus  of  No.  5968  is  preserved.  The  head  is  not  globular,  but  consists  of  a 
broad  ridge,  whose  axis  makes  a  small  angle  with  the  shaft  of  the  bone,  and  a  groove  on  the 
radial  side.    The  whole  structure  is  exactly  like  that  of  the  humerus  of  the  species  oiTrachemys. 

No.  6010  was  collected  on  Little  Dry  Creek,  Wyoming,  and  therefore  belongs  to  horizon 
B.  It  is  represented  by  only  the  plastron.  Fig.  400  shows  the  upper  side  of  the  anterior  lobe 
and  fig.  401  the  beveled  surface  of  the  hinder  lobe.  Both  in  front  and  behind,  the  beveled 
horn-covered  surfaces  are  wider  than  in  No.  5988.  These  figures  represent  the  condition  found 
in  a  certain  number  of  specimens  that  must  be  referred  to  this  species. 

Figs.  402  and  403  represent  a  remarkable  specimen  which  belongs  to  the  Yale  University 
Museum.  It  was  collected  by  one  of  Professor  Marsh's  parties  in  1874,  in  the  Bridger  Eocene, 
near  Millersville,  Wyoming.  It  was  described  in  the  American  Journal  of  Science  by  Hay, 
as  cited  above.  It  is  interesting  because  of  the  presence  of  one  extra  neural,  two  extra  pairs  of 
costal  plates,  one  extra  pair  of  peripherals,  an  extra  vertebral  scute,  an  extra  pair  of  costal 
scutes,  and  an  extra  pair  of  marginal  scutes.  These  supernumerary  structures  are  not  regarded 
as  of  even  specific  value.  It  is  to  be  observed,  however,  that  the  anterior  lobe  of  the  plastron 
narrows  more  rapidly  than  usual  and  that  the  base  of  the  hinder  lobe  is  wider  than  usual;  is, 
indeed,  more  than  half  the  length  of  the  plastron. 

Two  specimens  in  Princeton  University  are  referred  to  E.  wyomingensis.  These  are 
numbered  10071  and  10072.  In  both  of  these  the  axillary  and  the  inguinal  buttresses  extend 
inward  but  little  beyond  the  free  borders  of  the  bases  of  the  plastral  lobes.  In  this  respect 
these  specimens  differ  greatly  from  those  of  £.  haydeni,  to  which  they  might  easily  be  referred. 
Like  the  latter  species,  No.  10071  has  the  fourth  neural  octagonal,  while  No.  10072  has  this 
neural  heptagonal. 


Figs.  404-406. — Echmatemys  haydeni.     Carapace  and  plastron.     Xj. 


404.  Portion  of  carapace  of  type.    U.S.N.  M, 
406.  Plastron 


405.  Portion  of  carapace.    No.  1067  A.  M.  N.  H. 
No.  1067  A.M.N.H. 


Echmatemys  haydeni  (Leidy). 
Plate  47,  fig.  2;   text-figs.  404-410. 

Emys  haydeni,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1870,  p.  123;  Ann.  Report  U.  S.  Gaol.  Surv.  Wyoming, 
etc.,  1870  (1871),  p.  366. — Cope,  Vert.  Tert.  Form.  West,  1884,  p.  137. — Hay,  Bibliog.  and  Cat. 
Foss.  Vert.  N.  A.,  1902,  p.  448. 

Emys  ■wyomingensis,  Leidy,  Ann.  Report  U.  S.  Geol.  Surv.  Montana,  etc.,  1871  (1872),  p.  367  (in  part); 
Contrib.  Ext.  Fauna  West.  Terrs.,  1873,  p.  145  (in  part),  plate  ix,  fig.  6. 


3H 


FOSSIL    TURTI.KS    OK    NORTH    AMERICA. 


Neural. 

Length. 

Width. 

I 

5° 

3° 

2 

3» 

3' 

3 

34 

19 

4 

33 

J7 

5 

i6 

»7 

6 

»3 

37 

Width.              J 

Vertebral . 

Length. 

In  front. 

Greatest. 

I 

73 

87 

87 

a 

70 

49 

54 

3 

go 

37 

S3 

4 

5° 

6S 

Dr.  Leidy's  type  ot  the  present  species  was  found  near  Fort  Bridger,  Wyoming,  and 
probably  in  the  level  now  known  as  B.  It  belongs  to  the  U.  S.  National  Museum  and  has  the 
number  109.     It  consists  of  the  anterior  part  of  the  carapace.     This  was  figured  by  Leidy, 

but  the  peripherals  were  omitted,  having  been  found  afterwards. 
These  have  been  included  in  fig.  404. 

From  the  front  of  the  nuchal  to  the  anterior  border  of  the 
seventh  neural  is  255  mm.  The  length  of  the  nuchal  is  57  mm.; 
the  width  in  front,  60  mm.;  the  greatest  width,  75  mm.  The 
fourth  neural  is  octagonal.  The  table  shows  the  dimensions  of 
the  neurals. 

The  first  peripheral  measures  50  mm.  along  the  free  border. 
The  height  is  48   mm.    The  sulcus  between  the  costal  and  the 
marginal  scutes  runs  about  20  mm.  below  the  upper  border.    The 
dimensions  of  the  vertebral  scutes  are  given  in  the  table  below. 

No.  1067  of  the  American  Museum  was  found  by  Cope  in  the  Bridger  region.  Fig. 
405  shows  the  carapace;    fig.  407,  the  plastron  seen  from  below;    while   plate   47,   fig.  2, 

shows  the  plastron  from  above.  This  figure  is  to  be 
compared  with  fig.  i  of  the  same  plate,  E.  wvomltigensis, 
especially  as  to  the  origins  of  the  axillary  and  inguinal 
buttresses. 

In  the  American  Museum  is  found  the  specimen 
described  by  Cope  as  belonging  to  this  species.  Its 
number  is  1072.  It  resembles  the  specimen  to  be 
described  below,  except  that  the  rib-heads  are  broader, 
having  the  diameter  of  12  mm.  where  they  leave  the 
carapace.  The  individual  was  slightly  larger  than  No.  1067,  but  not  enough  larger  to 
account  for  the  difference. 

No.  1071  of  the  American  Museum  is  a  part  of  the  Cope  collection,  but  the  exact  locality 
where  it  was  found  is  not  known.  It  came,  however,  from  the  Fort  Bridger  region.  It  belonged 
to  an  individual  whose  shell  was  about  250  mm.  long.  The  bones  and  sutures  have  an  appear- 
ance of  immaturity.  The  features  that  characterize  the  specimens  already  mentioned  hold 
good  here.  The  form  was  convex,  as  described  by  Cope.  The  fourth  neural  is  octagonal,  the 
fifth  quadrate.  The  vertebral  scutes  are  proportionally  wider  than  in  the  type,  but  this  may 
be  due  to  less  advanct  age.  Over  the  bridge  the  costo-marginal  sulci  ran  very  close  to  the 
costo-peripheral  sutures.  On  the  costals  are  seen  concentric  grooves,  which  show  the  growth  of 
the  horny  scutes.  On  the  first  costal  bone  these  are  at  an  average  distance  apart  of  7  mm.,  a 
fact  indicating  rather  rapid  growth.  The  plastron  is  not  greatly  thickened,  the  front  of  the 
hypoplastron  being  11  mm.  The  lip  has  a  notch  in  front,  which  cuts  off  a  tooth  on  each  side. 
Behind  this  tooth  the  thickness  is  1 1  mm. 

Another  specimen  in  the  American  Museum  of  Natural  History  which  is  referred  to  E. 
haydeni  is  numbered  3943.  It  consists  of  a  shell  lacking  only  some  of  the  hinder  peripherals. 
It  was  collected  in  1904,  by  Mr.  Walter  Granger,  in  the  Bridger  Eocene  beds,  about  the  middle 
of  the  length  of  Cottonwood  Creek,  and  therefore  belongs  to  the  lower  portion  of  horizon  B. 
The  shell  is  crusht  laterally,  so  that  the  height  is  probably  greater  than  in  life,  being  now  182 
mm.  The  length  of  the  plastron  is  370  mm.,  from  which  it  is  estimated  that  the  carapace  had 
originally  a  length  of  more  than  400  mm.     The  present  width  is  262  mm. 

The  carapace  (fig.  407)  is  smooth  and  the  sulci  are  moder- 
ately imprest.  On  the  last  neural  and  the  suprapygals  there  is  a 
trace  of  a  low  keel.  The  nuchal  bone  has  a  length  of  69  mm.,  a 
width  of  56  mm.  in  front,  and  a  maximum  width  of  about  80 
mm.  The  neurals  are  broad.  Two  of  these  are  octagonal,  the 
second  and  the  fourth,  but  this  is  believed  to  be  only  an  individual 
variation.  In  the  American  Museum  of  Natural  History  there  is 
a  specimen  of  Chelydra  serpentina  in  which  the  same  neurals  are 
octagonal.  The  table  herewith  presents  the  dimensions  of  the 
neurals  of  3943. 


Neural. 

:    Length. 

Width. 

I 

5* 

35 

2 

43 

41 

3 

46 

26 

4 

46 

31 

5 

4" 

37 

6 

29 

34 

7 

22 

39 

8 

»S 

34 

KMYDIDi*;. 


315 


The  first  suprapygal  has  a  length  of  34  mm.  and  a  width  of  29  mm.     The  second  supra- 
pygal  is  38  mm.  long  and  about  78  mm.  wide. 

The  dimensions  of  the  peripherals  appear  in  the  following  table. 


Dimensions  of  peripherals. 

Dimensions  of 

vertebral 

scutes. 

Dimensions  of  marginal  scutes. 

No. 

Height. 

Width 
of  free 
border. 

Width 
of  upper 
border. 

No. 

Length. 

88 

82 

9> 

77 

Width 
of  front. 

8s± 
59 
43 
5» 

Greatest 
width. 

85± 

66 

60 

No.      ?''«•" 
of  front. 

Greatest    Length  of  ] 
height,    free  border.. 

I 
2 

3 
6 
8 

49 
49 

50 
62 

S3 
5° 
47 
48 

34 
3' 

28 

46 

4» 

2 
3 

4 

1             20 
»     ,      ^5 

3  !       ^3 

4  26 

7             30 

^7                49 
3°                49 
24                49 

^9                 45 
40                  51 

The  free  border  of  the  nuchal  and  that  of  the  first  pair  of  peripherals  are  acute. 

The  vertebral  scutes  are  long  and  narrow.  The  dimensions  of  these  and  the  marginal 
scutes  are  given  in  the  tables  above. 

As  stated  already,  the  plastron  (fig.  408)  has  a  length  of  370  mm.  The  anterior  lobe  is  102 
mm.  long  and  163  mm.  wide.    The  length  is  therefore  about  63  per  cent,  of  the  width.    The 


-,-.xr/ 


Figs.  407  and  408. — Echmatemys  haydeni.    Carapace  and  plastron.    X  \-    No.  3943  A.  M.  N.  H. 

407.  Carapace.  408.   Plastron. 

free  border  is  acute  on  the  hyoplastrals,  but  becomes  thickened  and  subacute  and  finally 
rounded  near  the  lip.  The  latter  is  63  mm.  wide.  This  has  the  appearance  of  having  been  cut 
off  square  in  front,  with  a  short,  blunt  tooth  on  each  side.  On  the  upper  side  (fig.  409),  from 
the  acute  free  border  of  the  lip,  the  bone  thickens  backward  a  distance  of  25  mm.,  where 
the  thickness  is  14  mm.  The  width  of  the  horn-covered  surface  at  the  union  of  the  epiplastral 
and  hvoplastral  bones  is  22  mm.  The  entoplastron  has  a  length  of  66  mm.  and  a  width  of  75 
mm.     The  bridge  is  148  mm.  wide. 


3i6 


FOSSIL   TURTLES   OF   NORTH    AMERICA. 


The  hinder  lobe  is  ii  mm.  long  and  160  mm.  wide,  the  length  being  thus  70  per  cent,  of 
the  width.  There  is  a  posterior  notch  of  considerable  size.  The  beveled  surface  on  the  upper 
side  of  the  lobe,  at  the  hypoxiphiplastral  suture,  is  29  mm.  wide. 

The  gular  scutes  differ  in  size.  That  on  the  left  is  48  mm.  long.  The  humerals  are  42  mm. 
long;  the  pectorals,  72  mm.;  the  abdominals,  84  mm.;  the  femorals,  69  mm.;  the  anals,  55 
mm.,  measured  to  the  end  of  the  plastron.  The  axillary  scutes  are  large,  but  they  do  not 
reach  backward  to  the  fifth  marginals.  The  inguinals  are  large  and  extend  forward  so  as 
just  to  touch  the  sixth  marginals. 

The  inguinal  buttresses  extend  far  inward  reaching  at  least  half-way  from  the  free  border 
of  the  base  of  the  hinder  lobe  to  the  midline. 

No.  6088  of  the  American  Museum  is  referred  to  E.  haydeni.  It  was  found  at  Henry  Fork 
Hill,  100  feet  below  the  white  stratum,  in  horizon  C.  The  carapace  had  a  length  of  about  400 
mm.     For  a  view  of  the  upper  side  of  the  border  of  the  hinder  lobe  see  fig.  410. 

E.  haydeni  is  to  be  distinguisht  from  E.  wyomingensis  by  the  axillary  and  inguinal  but- 
tresses. In  the  latter  species  the  inguinal  buttresses  extend  inward  not  more  than  one-third  the 
distance  from  the  free  border  of  the  hinder  lobe  to  the  midline;  while  in  E.  haydeni  they  extend 


410. 


Figs.  409  and  410. — Echmatemys  haydeni.     Portions  of  lobes  of  plastron.     Xi- 


409.  Upper  surface  of  anterior  lobe.  No.  3943  A.M.N. H. 

410.  Upper  surface  of  free  border  of  hinder  lobe  of  plastron. 


No.  6088  A.M.N. H. 


inward  at  least  half-way  to  the  midline.  Usually,  if  not  always,  the  fourth  neural  of  £.  haydem 
is  octagonal,  but  occasionally  this  is  true  of  the  same  neural  of  £.  wyomingensis.  Usually  the 
upper  side  of  the  epiplastral  lip  of  £.  wyomingensis  is  short,  the  thickening  not  extending  back- 
ward so  far  as  in  E.  haydeni. 

E.  shaughnessiana  is  to  be  distinguisht  by  the  relatively  wider  vertebral  scutes  and  the 
thickened  and  obtuse  free  borders  of  the  front  of  the  carapace. 

Echmateihys  stevensoniana  (Leidy). 
Plate  48,  figs.  I,  2;  text-figs.  411-413. 

Emys  stevensonianus,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1870,  p.  5. 

Emys  stevensoni,  Leidy,  Ann.  Report  U.  S.  Geol.  Surv.  Wyoming,  etc.,  1870  (1871),  p.  366. 

Emys  wyomingensis,  Leidy,  Ann.  Report  U.  S.  Geol.  Surv.  Montana,  etc.,  1871  (1872), p. 367  (in part); 

Contrib.  Ext.  Fauna  West.  Terrs.,  1873,  p.    141,  plate  ix    figs.   2-4.— Hay,   Bibliog.  and   Cat. 

Foss.  Vert.  N.  A.,  1902,  p.  448  (in  part). 

Dr.  Leidy's  type  of  the  present  species  was  collected  somewhere  in  the  vicinity  of  Fort 
Bridger,  Wyoming,  and  therefore  probably  in  the  lower  portion  of  the  Bridger  Eocene.  His 
specimen  consisted  of  a  portion  of  a  carapace  showing  the  whole  series  of  neurals  and  the 


EMYDIDuS;. 


317 


proximal  ends  of  several  costals  and  a  portion  of  the  plastron.  It  is  not  certain  that  the  two 
portions  of  the  shell  belonged  to  the  same  individual,  but  it  is  probable  that  they  did.  These 
bones  are  figured  as  cited  in  the  synonymy.  With  them  were  figured  and  referred  to  the  same 
species  a  left  epiplastron  of  another  individual.  This  bone  was  barely  mentioned  in  the  original 
description. 

The  type  is  in  the  U.  S.  National  Museum.  The  piece  of  carapace  bears  the  number  965; 
the  piece  of  plastron,  the  number  963.  The  original  of  Leidy's  fig.  4  of  the  plate  cited  bears 
the  number  976. 

Later  Dr.  Leidy  referred  all  these  bones  to  his  Emys  wyomingensis.  It  is  the  present 
writer's  opinion  that  the  two  forms  are  not  identical :  but  the  fragment  of  plastron  represented 
by  Leidy's  fig.  4  probably  belongs  to  E.  wyomingensis. 

It  is  to  be  remarkt  concerning  the  plastron  described  by  Leidy  that  the  free  border  of  the 
anterior  lobe,  from  the  humero-pectoral  sulcus  forward  to  the  gulo-humeral,  is  broken  away,  so 


411. 


412. 


Figs.  411-413. — Echmatemys  stevensoniana.     Carapace  and  plastron. 
No.  6084  A.  M.  N.  H. 

411.  Carapace.    X}.  412.  Plastron.     Xj. 

413.  Upper  surface  of  free  border  of  hinder  lobe  of  plastron.    XJ. 

that  the  edge  does  not  extend  out  as  far  as  it  naturally  did.  The  edge  of  his  drawing  ought  to 
extend  out  about  i\  mm.  further  than  it  does.  Attention  may  be  called  to  the  form  and 
dimensions  of  the  vertebral  scutes  of  Leidy's  type,  as  they  are  represented  in  his  figure. 

In  the  American  Museum  of  Natural  History  is  a  specimen  which  is  referred  to  this  species. 
It  is  a  nearly  complete  shell,  lacking  only  the  right  epiplastron.  This  shell  was  collected  in  the 
Bridger  beds  of  southwestern  Wyoming  by  the  museum's  party  in  the  year  1893.  No  further 
details  are  recorded  regarding  the  locality  and  the  level.  The  matrix  filling  the  shell  is  a  coarse 
sand  in  which  are  inclosed  nodules  of  a  greenish  clay.    The  catalog  number  is  6084. 

The  total  length  of  the  carapace,  in  a  straight  line,  is  355  mm. ;  the  greatest  width  240  mm. ; 
the  greatest  elevation  125  mm.,  but  this  in  life  was  greater.  The  plastron  is  convex,  an  indica- 
tion that  the  individual  was  a  female. 

In  outline  the  carapace  (plate  48,  fig.  i ;  text-fig.  411)  is  a  rather  narrow  oval,  contracted 
in  front  of  the  fore  legs.  It  is  slightly  excavated  above  the  neck  and  the  hinder  end  is  rather 
pointed.     Posteriorly  the  peripherals  flare  slightly  upward.    The  free  borders  of  the  nuchal. 


3'S 


FOSSIL     lURTLI'S    Of-    NORTH    AMERICA. 


Element. 


Length. 


the  front  pair  of  peripherals,  and  the  hinder  peripherals  are  acute.     The  borders  ot  the  carapace 
are  nowhere  notcht.     The  surface  is  smooth  or  relieved  only  by  longitudinal  striations. 

The  nuchal  bone  is  53  mm.  long,  34  mm.  wide  in  front, 
and  60  mm.  where  widest,  the  table  presenting  the  dimen- 
sions of  the  remaining  median  bones. 

The  table  below  presents  the  dimensions  of  some  of 
the  peripherals  and  of  the  vertebral  and  marginal  scutes. 
The  third  peripheral  has  a  height  ecjual  to  56  per  cent, 
of  the  height  of  the  first  costal,  from  the  neural  to  the 
peripheral. 

The  vertebral  scutes  are  relatively  narrow  and  the 
sides  of  the  second  and  third  are  moderately  bracket- 
shaped.     The  interior  and  posterior  are  expanded. 

The  nuchal  scute  is  10  mm.  wide  posteriorly  and  its 
length  is  19  mm.    The  costo-marginal  sulci  run  well  below 
the  costo-peripheral  suture.     The   dimensions  of  five  of 
the  marginal  scutes  are  given  in  the  table  below,  on  the  right. 

The  total  length  of  the  plastron  (plate  48,  fig.  2;  text-fig.  412)  is  317  mm.  The  anterior 
lobe  is  88  mm.  long  and  126  mm.  wide  at  the  base,  the  length  being  thus  70  per  cent,  of  the 
width.  The  lateral  borders  run  directly  forward  to  the  hyoepiplastral  suture,  then  curve  to 
the  lip.    This  had  a  width  of  56  mm.  and  had  a  tooth  on  each  side.    The  lip  does  not    extend 


Neural  i 

Neural  2 

Neural  3 

Neural  4 

Neural  5 

Neural  6 

Neural  7 

Neural  8 

Suprapvgal    1  . 
Suprapygal    2. 

Pygai .'. 


36 

3* 
34 
35 
29 

^3 
22 
16 
33 
38 
17 


Width. 


21 

25 

H-S 

*4-5 

i7 

27 

28 

18.S 

^5 

63 

z8 


Dimensions 

of  peripherals. 

Width 

Width 

No.      Height. 

of  free 

of  upper 

border. 

38 

border. 

'             39 

17 

2            40 

38 

23 

3            4' 

48 

26 

6            48 

48 

46 

8            53 

42 

3' 

Dimensions  c 

f  vertebral 

scutes. 

D 

mensions  of  marginals. 

No.      Length 

Width 
in  front. 

Greatest 
width. 

No. 

Height 
in  front. 

'9 
24 
20 
21 

38 

Greatest    ''f"?'' 
,       , .       of  free 

•"^'S*"-     border. 

^3             3" 
27            35 
21            40 

^7              44 
43              42 

58 
2       67 

3  68 

4  78 

5  5° 

74 
37 
35 
37 
14 

74 
57 
53 
58 
67 

1 
2 
3 
4 
9 

as  far  forward  as  the  nuchal  bone.  The  thickening  on  the  upper  side  of  the  symphysis  of  the 
epiplastrals  extended  backward  25  mm.  The  greatest  thickness  of  the  epiplastrals  is  13  mm., 
and  between  these  thickenings  the  bones  are  slightly  channeled  longitudinally.  The  thickness 
of  the  symphysis  is  13  mm.  The  horn-covered  surface  of  the  upper  side  of  the  epiplastron,  at 
the  suture  with  the  hyoplastron,  is  18  mm.  wide.  The  entoplastron  is  47  mm.  long  and  57  mm. 
wide.     It  is  pointed  in  front;    rounded  behind. 

The  bridge  has  a  width  of  136  mm. 

The  hinder  lobe  is  105  mm.  long,  and  140  mm.  wide  at  the  base.  The  length  is  therefore 
75  per  cent,  of  the  width.  The  buttresses  arise  far  within  the  free  border  of  this  lobe.  The 
beveled  surface  of  the  upper  lobe  (fig.  413),  at  the  suture  with  the  xiphiplastrals,  is  28  mm. 
wide.  The  free  borders  of  the  lobe  are  acute.  The  posterior  notch  is  about  28  mm.  wide  and 
6  mm.  deep.  The  posterior  buttresses  appear  to  have  extended  at  their  bases  about  half-way 
to  the  midline.     How  high  they  rise  has  not  been  determined. 

The  gulars  are  45  mm.  long;  the  humerals,  20  mm.;  the  pectorals,  63  nmi.;  the  abdomi- 
nals, 91  mm.;  the  femorals,  52  mm.;  and  the  anals,  45  mm. 

The  axillary  scute  is  large,  extending  outward  and  backward  to  form  contact  with  the 
fifth  marginal  for  a  distance  of  6  mm.  The  inguinal  scute  extends  forward  within  13  mm.  of 
the  sixth  marginal. 

From  E.  naomi  the  species  differs  in  having  a  smoother  shell,  with  less  deeply  imprest 
channels  for  the  sulci,  and  in  having  narrower  neurals.  The  carapace  of  E.  stevensoniana  is 
more  contracted  in  front.  E.  shaughnesstana  is  set  off  by  the  bluntly  rounded  anterior  border 
of  the  carapace.  From  E.  legle  the  present  species  is  distinguish!  by  the  larger  axillary  scute, 
the  deep  grooving  of  the  carapace,  the  lower  position  of  the  costo-marginal  sulci,  the  relatively 
broader  and  shorter  anterior  lobe  of  the  plastron,  etc.    In  E.  ocyrrhoi'  the  carapace  is  smooth, 


kmydida:.  319 

the  costal  plates  are  alternately  wide  and  narrower  at  their  opposite  ends,  the  beveled  surface 
of  the  upper  side  of  the  hinder  lobe  is  narrower  and  the  axillary  scute  is  far  from  reaching  the 
fifth  marginal.  Other  differences  are  noted  under  E.  ocyrrho'e.  E.  arcthusa  is  distinguisht 
by  the  contracted  epiplastral  lip  and  other  characters. 

E.  stevensontana  is  distinguisht  from  E.  septaria,  which  it  most  resembles,  by  not  having 
the  anterior  lobe  so  much  expanded,  and  by  not  having  the  costo-marginal  sulcus  so  near  the 
upper  edge  of  the  peripheral  bones.  The  form  and  the  dimensions  of  the  anterior  marginal 
scutes  are  quite  different  in  the  two  species;  and  the  pectoro-abdominal  sulcus  of  E.  steven- 
sontana does  not  approach  so  closely  at  the  midline  the  hyohypoplastral  suture  as  it  does  in 
both  the  specimens  of  E.  septaria  in  the  American  Museum. 

Echmatemys  septaria  (Cope). 
Text-figs.  414-420. 

Emvs  septan  a.  Cope,  bth  Ann.  Report  U.  S.  Geol.  Surv.  Terrs.,  1873,  p.  625;  Anier.  Naturalist,  xvi,  1882, 
p.  992;  Vert.  Tert.  P'orm.  West,  1884,  pp.  130,  139,  plate  xvii,  figs.  9-13. — Hay,  Bibliog.  and  Cat. 
Foss.  Vert.  N.  A.,  1902,  p.  448. 

Echmatemys  septaria,  Hay,  Bull.  Amer.  Mus.  Nat.  Hist.,  xxil,  p.  28,  fig.  i. 

The  type  of  this  species  is  in  the  U.  S.  National  Museum  and  consists  of  a  tolerably  com- 
plete plastron;  a  portion  of  the  central  region  of  the  carapace,  including  the  third,  fourth,  and 
fifth  neurals,  with  portions  of  the  second,  third,  and  fourth  left  costals;  and  a  fragment  showing 
parts  of  the  fifth,  sixth,  and  seventh  right  costals  and  abutting  peripherals.  This  type  was 
collected  in  the  beds  of  the  Washakie  basin  in  the  badlands  of  South  Bitter  Creek,  Wyoming. 

All  of  Professor  Cope's  illustrations  are  one-third  the  natural  size,  instead  of  one-fourth. 
Fig.  12  represents  the  piece  which  includes  the  three  neurals  mentioned  and  the  corresponding 
costals,  but  the  sutures  bounding  these  bones  are  not  shown.  Moreover,  the  lower  end  of  the 
figure  is  the  forward  end  of  the  fragment.  The  fragment  illustrated  by  fig.  13  is  not  stated  to 
have  had  any  connection  with  that  of  fig.  12;  but  the  two  pieces  join  accurately.  If  fig.  13  is 
conceived  as  being  swung  around  so  that  the  end  of  the  suture  near  its  lower  right-hand  corner 
shall  coincide  with  the  end  of  the  fracture  seen  in  fig.  12,  at  the  bottom  of  the  concave 
border  on  the  right-hand  side,  the  pieces  will  be  in  their  natural  relation. 

The  first  neural  bone  is  42  mm.  long  and  23  mm.  wide.  The  next  two  neurals,  all  whose 
form  can  be  determined,  are  hexagonal,  with  the  broad  end  forward.  Of  these  the  second  is 
35  mm.  long  and  30  mm.  wide,  while  the  third  is  40  mm.  long  and  27  mm.  wide.  The  periph- 
erals are  high,  the  fourth  and  fifth  rising  above  the  edge  of  the  shell  about  42  mm.  The 
nuchal  and  the  peripherals  abutting  on  it  have  sharp  free  borders.  The  nuchal  is  50  mm.  long 
and  67  mm.  wide. 

The  first  vertebral  scute  is  67  mm.  long  and  80  mm.  wide;  the  second  78  mm.  long  and 
66  mm.  wide  at  the  point  of  the  brackets.  The  nuchal  scute  is  narrow,  about  20  mm.  All 
the  epidermal  sulci  are  rather  deeply  imprest,  but  are  not  broad. 

The  inguinal  buttresses  extend  well  up  into  the  carapace.  They  reach  inward  about 
40  mm.  from  the  inner  surface  of  the  fifth  costal  plate.  They  are  very  thin  in  comparison  with 
those  of  £.  shaughnessiana.  Cope  states  (Ann.  Rep.  Hayden  Surv.  for  1872,  p.  625)  that  this 
buttress  is  connected  with  both  the  fifth  and  sixth  costal  plates.  An  examination  of  his  type 
shows  that  on  the  left  side  the  union  is  almost  entirely  with  the  fifth  costal,  while  the  sixth  only 
just  comes  into  contact  with  the  buttress.  On  the  right  side  the  sixth  takes  more  part  in  the 
articulation.  The  position  of  this  buttress  probably  varies  somewhat  in  difl^erent  individuals 
of  this  species.  In  No.  6085,  American  Museum  of  Natural  History,  described  below,  it 
comes  into  contact  with  the  sixth  costal.  In  No.  1077,  American  Museum  of  Natural  His- 
tory, the  buttress  rests  on  the  middle  of  the  fifth  costal  (fig.  414),  and  is  hence  far  from  the 
border  of  the  sixth;  but  this  specimen  appears  to  be  abnormal  in  some  other  respects.  There 
are  considerable  differences  between  Cope's  type  and  No.  1077  in  the  structure  of  the  costals 
and  peripherals  in  the  region  of  the  inguinal  notch.  There  is  no  considerable  difference  in  the 
widths  of  the  costals,  and  the  peripherals  coincide  pretty  closely  with  the  ends  of  the  costals. 
In  No.  1077,  American  Museum  of  Natural  History,  the  arrangement  is  as  shown  in  fig.  414. 
This  figure  shows  parts  of  the  fourth,  fifth,  sixth,  and  seventh  costals  and  the  seventh,  eighth. 


320 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


and  ninth  peripherals.  The  dotted  line  shows  the  position  of  the  inguinal  buttress  on  the  inner 
side  of  the  shell. 

In  the  American  Museum  of  Natural  History  there  are  various  specimens  which  enable 
us  to  add  much  to  our  knowledge  of  the  structure  of  this  species.  Unfortunately,  none  of  the 
specimens  is  complete;  and  even  when  all  are  taken  together,  we  are  left  in  ignorance  of  much 
of  that  part  of  the  carapace  behind  the  inguinal  notch. 

Among  the  materials  referred  to  are  some  which  were  collected  by  Professor  Cope  in  1872, 
but  which  do  not  appear  to  have  been  identified  by  him.  One  of  these,  No.  1077,  furnishes  the 
greater  portion  of  the  anterior  lobe  of  the  plastron;  the  hinder  lobe,  except  the  hinder  ends  of 
the  xiphiplastrals;  and  a  piece  (fig.  414)  of  the  carapace  consisting  of  parts  of  fourth,  fifth, 
sixth,  and  seventh  costals  and  the  sixth,  seventh,  and  eighth  peripherals.  The  remains  of 
another  individual,  No.  1076,  somewhat  larger  than  the  type,  present  the  second  and  third 
peripherals  of  both  sides,  many  fragments  of  costals,  nearly  the  whole  of  both  epiplastra,  and 
a  portion  of  both  xiphiplastrals.  A  third  specimen.  No.  1079,  from  Haystack  Mountain, 
Wyoming,  consists  of  the  epiplastra  of  a  still  larger  individual. 

The  best  example  of  this  species  in  the  American  Museum  is  numbered  6085,  and  was  col- 
lected in  the  Bridger  beds  of  Wyoming,  by  the  expedition  sent  out  in  1893.  The  exact  locality 
and  level  are  not  on  record.     This    individual  lacks  the  whole  of  the  carapace  behind  the 


Figs.  414-416. — Echmatemys  septaria.     Carapace  and  plastron. 


414. 


415, 


Portion  of  carapace.  Xi.  No.  1077  A.M.N.  H.  Presents  the  seventh, 
eighth  and  ninth  peripherals  and  portions  of  fourth  to  seventh  costals. 
Dotted  line  shows  course  of  articulation  oi  inguinal  buttress  on  inner 
surface. 

Anterior  portion  of  carapace.    Xi.    No.  6085  A.  M.N.  H. 


416.  Plastron.  XJ.    No.  6085  A.  M.  N.  H. 

inguinal  notch;  neurals  and  costals  immediately  in  front  of  this  notch  are  crusht  and  damaged, 
but  the  remainder  of  the  carapace  and  the  whole  of  the  plastron  are  in  fine  condition.  It  is  ac- 
companied by  another  chelonite,  No.  6089,  which  presents  the  anterior  two-thirds  of  both 
carapace  and  plastron  in  fine  condition.  Unless  otherwise  stated  the  following  description  is 
derived  from  No.  6085. 

The  length  of  the  carapace  (fig.  415)  can  not  be  determined  with  exactness;  but  it  was 
close  to  380  mm.  The  breadth  was  at  least  210  mm.  The  elevation  of  the  shell  in  life  can  not 
now  be  determined.  It  is  now  141  mm.  high.  The  indications  furnisht  by  the  various  speci- 
mens are  that  the  shell  was  quite  convex.  The  plastron  is  nearly  flat  in  the  middle  portion; 
but  the  anterior  lobe  rises  in  front;  and  the  hinder  lobe  is  somewhat  concave,  especially  near 
the  borders. 

At  the  sides  the  carapace  rises  from  the  plastron  upward  and  outward  about  57  mm.,  then 
turns  steeply  upward,  and  curves  toward  the  midline  of  the  back.  The  lateral  carina  on  the 
bridge  peripherals  is  obtuse.  There  is  no  dorsal  carina;  nor  is  the  carapace  especially 
flared  upward  at  the  sides  in  front. 


EMYDIDj^. 


321 


The  neural  bones  are  of  moderate  width;   the  table  shows  their  dimensions: 
The  length  of  the  nuchal  was  close  to  56  mm.;   its  width  along  the  free  border  about  42  mm.; 
its  greatest  width  is  67  mm.    The  free  border  of  the  nuchal  and  those  of  the  first  peripherals 


Dimensions  of 

neurals. 

Dimensions  of  peripherals. 

No. 

Length. 

Width. 

2^ 

i7 

No. 

j  Width  of  1  Width  of 
j     Height.    '        free        '      costal 
1                     \     border.         border. 

3 

4^ 
34 
40 

2 
3 
5 

1 

,44                 37                  17 

I        40                36                 ii        1 

45                43                30        i 
45                 45                 45 

are  acute,  especially  as  shown  by  No.  6089;  but  the  bone  thickens  rapidly  toward  the  costals. 
The  thickness  of  the  first  and  second  peripherals  at  their  articulation  is  20  mm. 
The  dimensions  of  the  peripherals  are  shown  in  the  table  above. 


Vertebral. 

Marginal. 

Scute. 

Length. 

Width. 

Height. 

Length 
of  free 
border. 

In  front.     Greatest. 

In  front. 

Greatest. 

I 

2 
3 

65 
76 
7S± 

79                79 
38                6; 
38                6o± 

■5 
26 
30 

26 

35 
30 

3* 
37 
39 

The  upper  surface  of  the  carapace  is  nearly  smooth,  but  is  relieved  by  striation  and  faint 
lines  of  growth;  but  these  are  not  so  distinct  as  they  are  on  Cope's  type  of  E.  septaria.  The 
second  and  third  vertebral  scutes  are  urn-shaped,  expanded  in  front,  and  narrowed  behind. 
The  first  vertebral  is  the  broadest.  The  dimensions  of  vertebral  and  marginal  scutes  are  given 
in  the  second  table  above. 


Figs.  417  and  418. — Echmatemys  septaria.     Xi-     No.  6085  A.  M.  N.  H. 

417.  Upper  surface  of  free  border  of  hinder  lobe  of  plastron. 

418.  Section  across  shell  at  the  inguinal  buttresses.    Shows  the  sixth  peripheral  {per.  6),  the 

fifth  costal  plate  (<"./>.  5),  and  the  right  and  left  inguinal  buttresses  (r.  ing.,  I.  ing). 

It  will  be  observed  that  the  second  marginal  is  unusually  high.  This  is  true  in  both  No. 
6085  and  No.  6089.  As  shown  by  both  these  specimens,  the  costo-marginal  sulci  run  near  the 
costo-peripheral  sutures ;  in  No.  6085,  a  few  millimeters  below ;  in  No.  6089,  on  the  sutures. 

The  plastron  (fig.  416)  has  a  total  length  of  345  mm.  The  anterior  lobe  is  95  mm.  long  and 
133  mm.  wide  at  the  base,  the  length  thus  being  71  per  cent,  of  the  width.  The  entoplastron  is 
50  mm.  long  and  53  mm.  wide.    Immediately  in  front  of  the  axillary  notch  the  lobe  narrows  a 


322 


1-OSSII.    TURTLES    OF    NORTH    AMERICA. 


few  millimeters,  then  begins  to  expand  and  becomes  wider  than  at  the  base.  At  the  hyoepi- 
plastral  suture  the  lobe  narrows  again  and  passes  rapidly  to  the  lip.  This  is  relatively  narrow, 
47  mm.,  is  notcht  at  the  midline,  and  is  furnisht  on  each  side  with  a  blunt  tooth.  The  epiplas- 
trals  thicken  toward  the  lip  and  become  20  mm.  thick.  For  some  distance  on  each  side  of  the 
symphysis  of  the  bones  the  thickness  is  reduced  to  15  mm.  The  lateral  expansion  of  the  anterior 
lobe  and  the  lip  form  the  most  distinctive  characters  of  this  species. 

The  bridge  has  a  width  of  about  138  mm. 

The  hinder  lobe  is  1 14  mm.  long  and  156  mm.  wide.  It  is  notcht  behind,  as  in  the  other 
species  of  the  genus.  The  beveled  surfaces  (fig.  417)  on  the  upper  side  of  this  lobe  are  33  mm. 
wide  at  the  hypoxiphiplastral  sutures.  The  posterior  buttresses  (fig.  418)  are  wide,  beginning 
to  rise  from  the  floor  of  the  plastron  at  a  line  nearer  to  the  midline  than  to  the  free  border  of  the 
lobe.  They  are  articulated  to  the  fifth  and  sixth  costals  and  rise  to  a  height  of  65  mm.  above 
the  floor  of  the  plastron. 

The  gulars  have  a  length  of  54  mm.;  the  humerals,  31  mm.;  the  pectorals,  68  mm.;  the 
abdominals,  83  mm.;  the  femorals,  51  mm.;  the  anals,  49  mm.,  at  the  midjine.  The  axillary 
scute  has  not  reacht  the  fifth  marginal,  nor  the  inguinal  the  sixth. 

As  in  other  species  of  this  genus  the  posterior  buttresses  articulate  with  the  fifth  and 
sixth  costals.  Fig.  419  represents  the  anterior  lobe  of  the  plastron  of  No.  1077,  American 
419.  420. 


Fkjs.  419  AND  420. — Echmatemys  septarta.      Anterior  lobe  of  plastron.      X  i-      No.  1077  A.  M.  N.  H. 

419.  Lower  surface.  420.   Upper  surface. 

Museum  of  Natural  History.    It  will  be  observed  how  this  expands  in  front  of  the  base.    Fig. 

420  presents  a  view  of  the  same  bone  seen  from  above.    The  width  of  the  lip  is  indicated,  also 

the  backward  extension  of  the  thickening  of  the  epiplastrals. 

No.  10303  of  the  collection  at  Princeton  University  is  to  be  referred  to  this  species.     It 

lacks  only  a  small  portion  of  the  rear  of  the  carapace  and  the  tips  of  the  xiphiplastra.    It  was 

collected  in  1878,  at  Twin  Buttes,  Wyoming,  in  the  Bridger  beds,  belonging  to  level  C  or  D. 

The  carapace  was  close  to  335  mm.  long.    The  interior  of  the  shell  is  cleaned  out,  so  that  all 

parts  are  exposed.  The  sides  of  the  anterior  lobe  are 
hatchet-shaped,  as  is  peculiar  to  the  species.  The  horn- 
covered  areas  on  the  upper  side  of  the  hinder  lobe  are  39 
mm.  wide. 

The  vertebral  scutes  are  narrow  at  the  ends,  wide 
in  the  middle,  the  measurements  being  given  in  the 
accompanying  table. 

These  scutes  are  much  wider  in  proportion  to  their 
length  than  in  Cope's  type  and  other  specimens  studied. 

The  sulci  are  broad  and  deeply  imprest.     It  is  possible  that  the  specimen  belongs  elsewhere. 

Nos.  1C073  and  10304  of  the   Princeton  collection  are  likewise  referred  to  E.  septarta. 

In  the  Philadelphia  Academy  collection  is  the  specimen  which  Leidy  described  as  Emys 

ivyomingensis  (Contrib.,  etc.,  pp.  148,  152,  153,  No.  14).    It  is  regarded  by  the  present  writer 

as  belonging  to  E.  septaria.     The  sulci  are  deeply  sunken  and  the  surface  of  the  carapace  is 

corrugated.    The  axillary  and  the  inguinal  scutes  are  well  developt. 


Vertebral. 

Length. 

Width. 

Anteriorly.    Greatest. 

I 

64 

»7 

1 
i 

4 

74 
78 

45 
39 

47 

77 
76 
S3 

KMYDID^;. 


3^3 


It  is  unfortunate  that  so  many  of  the  specimens  which  must  be  referred  to  this  species  are 
devoid  of  exact  records  regarding  their  levels  and  localities. 

Ecbmatemys  arethusa  sp.  nov. 
Plate  49,  figs.  I,  2;   text-figs.  421,  422. 

The  present  species  is  founded  on  a  single  specimen  which  was  collected  by  the  American 
Museum  expedition  of  1903  into  the  Badlands  in  the  vicinity  of  Bridger,  Wyoming.  The 
locality  in  which  it  was  obtained  is  the  western  portion  of  Grizzly  Buttes  and  the  level  the 
lower  portion  of  horizon  B.     The  catalog  number  of  the  specimen  is  5920. 

The  specimen  lacks  most  of  the  left  peripherals,  all  of  those  behind  the  ninth,  and  most  of 
the  xiphiplastrals.     It  has  likewise  been  crusht  toward  the  left  side. 

The  length  of  the  plastron  to  the  front  of  the  xiphiplastrals  is  225  mm.,  from  which  we 
estimate  that  the  whole  length  of  the  plastron  has  been  close  to  292  mm.  and  the  length  of  the 
carapace,  328  mm. 

With  the  exception  of  faint  longitudinal  striations,  the  surface  of  the  carapace  (plate  49, 
fig.  l)  is  smooth.    The  fourth  vertebral  scute  is  traversed  by  a  low  rounded  keel. 

The  nuchal  and   first  neural  have  been  fractured  so  that 
their  exact  dimensions  can  not  be  determined;  but  the  free  border 
of  the  nuchal  was  close  to  48  mm.  and  the  length  was  close  to  50 
mm.    The  neurals  furnish  the  measurements  shown  in  the  table. 
The  free  border  of  the  nuchal  and  first  pair  of  peripherals  is 
acute.    The  sulci  of  the  carapace  are  narrow  and  not  deeply 
imprest.    The  vertebral  scutes  are  narrow  and  the  sides  of  the 
second,  third,  and  fourth  are  nearly  parallel.    The  table  below 
presents  the  dimensions  of  some  of  the  peripherals,  and  of  some 
of  the  vertebral  and  marginal  scutes,  so  far  as  determinable. 
It  will  be  noted  that  the  fifth  vertebral  is  unusually  wide. 
The  nuchal  scute  has  a  width  posteriorly  of  9  mm.     Its  length  can  not  be  determined. 
The  costo-marginal  sulci  run  a  moderate  distance  below  the  costo-peripheral  sutures. 

As  already  stated,  much  of  the  plastron  (plate  49,  fig.  2;  text-fig.  421)  is  missing.  The 
length  of  the  anterior  lobe  is  78  mm.;  the  width  of  its  base  is  144  mm.    The  length  is  therefore 


Dimensions  of  marginal  scutes. 


Neural. 

Length. 

Width. 

I 

4» 

»5 

2 

33 

^9 

3 

35 

28 

4 

30 

17 

5 

3° 

30 

6 

21 

36 

7 

17 

33 

8 

21 

30 

Di 

mensions 

of  periphe 

rals. 

Width 

Width 

No. 

Height. 

of  free 

of  upper 

4> 

border. 

4^ 

border. 

I 

26 

1 

39 

43 

17 

3 

43 

43 

26 

6 

44 

43 

3<> 

8 

50 

38 

31 

D 

i  mensions 

of  verteb 

rals. 

No. 

Length. 

Width 
in  front. 

68 

'i 
Greatest 
width. 

68 

1 

64 

2 

66 

40 

53 

3 

65 

40 

53 

4 

60 

5° 

64 

1       ' 

42 

io5±    , 

4o. 

Height 
in  front. 

Greatest 
height. 

, 

I7± 

28 

2 

15 

15 

3 

22 

27 

4 

»7 

35 

9 

39 

4* 

Length 
of  free 

border. 

35± 

39 

43 

40 

40± 


only  54  per  cent,  of  the  width.  From  the  axillary  notches  its  free  borders  curve  regularly  to  the 
epiplastral  lip.  This  is  narrow,  40  mm.;  large  lateral  tooth  just  within  each  gular  sulcus. 
There  is  a  projecting  tooth  in  the  midline  and  on  each  side  of  it  a  minute  tooth.  On  the  upper 
side  of  the  epiplastrals  (fig.  422)  the  gular  scutes  expand  until  they  have  a  width  of  65  mm. 
The  thickening  of  the  epiplastrals  on  the  upper  side  extends  backward  from  the  tip  of  the 
median  tooth  23  mm.  The  greatest  thickness  of  the  epiplastrals  is  13  mm.  Just  outside  of 
the  gular  sulci,  on  the  upper  side,  the  horn-covered  surface  is  12  mm.  wide;  at  the  suture  with 
the  hyoplastrals,  14  mm.  The  entoplastron  has  a  length  of  50  mm.  and  a  width  of  58  mm. 
The  thickness  of  the  plastron  at  the  crossing  of  the  median  suture  and  that  between  the  hyo- 
plastrals and  hypoplastrals  is  15  mm. 

The  width  of  the  bridge  is  116  mm. 

The  length  of  the  hinder  lobe  can  not  be  determined.  Its  width  at  the  base  has  been  146 
mm.  The  inguinal  buttresses  arise  about  half-way  from  the  border  of  the  hinder  lobe  to  the 
midline, 


324 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


The  gular  scutes  are  41  mm.  long;   the  humeials,  25  mm.;    the  pectorals,  55  mm.;    the 
abdominals,  70  mm.;  and  the  femorals,  47  mm.  , 

The  axillary  scute  extends  backward  in  a  long  point  to  come  into  bare  contact  with  the 
fifth  marginal.     The  inguinal  scute  extends  forward  and  joins  narrowly  the  sixth  marginal. 

This  species  differs  from  E.  naomi 
in  the  form  of  the  vertebral  scutes,  in 
the  lack  of  grooves  for  the  sulci  of  the 
carapace,  in  the  very  different  form  of 
the  front  of  the  anterior  lobe,  and  in 
the  axillary  and  inguinal  scutes.  The 
broad  neurals,  the  very  broad  fifth  ver- 
tebral scute,  and  the  plastral  lip  differ- 
entiate it  from  E.  st  even  son  tan  a.  The 
acute  anterior  border  of  the  carapace, 
the  plastral  lip,  and  the  advanct  posi- 
tion of  the  humero-pectoral  sulcus  sep- 
arate it  from  E.  shaughnessiana.  The 
very  different  plastral  lip,  among  other 
characters,  removes  it  from  E.septana. 
E.  ocyrrhoe  has  the  costal  plates  dif- 
ferentiated so  that  the  ends  are  alter- 
nately wider  and  narrower ;  the  epi- 
plastral  lip  is  different  from  that  of  E. 
arethusa;  as  are  also  the  axillary  and 
inguinal  scutes.  E.  agle  has  the  verte- 
bral scutes  urn-shaped,  the  anterior 
lobe  is  very  different,  and  the  axillary 
and  inguinal  scutes  fall  short  respect- 
ively of  the  fifth  and  sixth  marginals. 
The  plastral  lip  of  E.  cyane  is  widely  different;  the  axillary  scute  falls  short  of  the  fifth 
marginal;  the  inguinal  far  short  of  the  sixth;  the  second  and  third  peripherals  measure 
together  64  mm.  along  the  free  border,  while  the  same  bones  in  the  type  of  E.  arethusa  measure 
85  mm.  E.  haydeni,  so  far  as  known,  differs  in  having  the  fourth  neural  octagonal,  the  verte- 
bral scutes  narrower,  and  a  very  different  form  of  epiplastral  lip. 


Figs.  421  and  422. — Echmatemys  arethusa.     Anterior 
lobe  of  plastron.     X§.     No.  5920  A.  M.  N.  H. 


421 


Lower  surface. 


422.  Upper  surface. 


Echmatemys  cyane  sp.  nov. 

Figs.  ^^^-^^^. 

No.  5924  of  the  American  Museum  of  Natural  History  is  a  fragmentary  specimen  present- 
ing most  of  the  left  side  of  the  carapace,  including  four  neurals,  most  of  the  left  side  of  the 
plastron,  and  a  part  of  the  right  side.  The  specimen  was  secured  by  the  expedition  in  1903, 
into  the  Bridger  Eocene,  at  Grizzly  Buttes,  Wyoming.  Its  horizon  is  therefore  that  called  B. 
The  length  of  the  carapace  (fig.  423)  of  this  individual  can  not  be  exactly  determined. 
From  the  front  of  the  nuchal  to  the  hinder  end  of  the  sixth  neural  is  246  mm.,  from  which  fact 

it  is  estimated  that  the  carapace  had  a  length  of  340  mm.  Like 
most  of  the  Bridger  species  of  the  genus,  this  species  had  a  thick 
shell.     The  surface  of  the  carapace  is  mostly  smooth. 

Of  the  nuchal  only  a  portion  of  the  left  side  is  present,  but 
this  shows  that  its  width  in  front  was  very  close  to  50  mm.  The 
greatest  thickness  is  15  mm.  The  first  neural  is  not  present. 
Those  preserved  show  the  dimensions  given  in  the  table  here- 
with. These  neurals  have  a  thickness  of  12  mm.  The  costals 
have  the  two  ends  of  each  about  the  same  width.  The  width  of 
the  first  costal  equals  yy  per  cent,  of  its  height. 

The  dimensions  of  some  peripherals  and  of  some  vertebral  and  marginal  scutes  are  given 
in  the  table  on  the  following  page.     The  third  peripheral  is  half  as  high  as  the  first  costal. 


Neural. 

Length. 

Width. 

2 

33 

28 

3 

35 

28 

4 

33-5 

30 

5 

29 

30 

6 

2Z 

30 

EMYDID.ffi. 


32s 


The  seventh  peripheral  has  at  its  hinder  sutural  border  a  thickness  of  13  mm.  A  rather 
prominent  rounded  keel  runs  along  on  the  peripherals  over  the  bridge. 

The  broadest  vertebral  scute  is  the  first.  The  second  and  third  are  of  moderate  width,  with 
the  sides  somewhat  bracket-shaped. 


Dimensions  of  peripherals. 

Dimensions  of  vertebral  scutes.     ||     Dimensions  of  marginal  scutes. 

No. 

Height. 

Width 
of  free 
border. 

Width 
of  costal 
border. 

No. 

Length.    .'^;''\ 
"        m  front. 

Greatest 
width. 

No. 

Height 
in  front. 

Greatest 
height. 

Length 
of  free 
border. 

37 
40 
41 

2 

3 
6 

7 

39 
40 

:; 
48 

3» 

34± 

36 

43 

39 

»4 
10 
22 

44 
30 

I 
2 
3 

4 

52             96  ± 
80             52  ± 
73             40 

47 

96± 
60  ± 
60 
60 

I 
2 

7 

13 
20 

»3 
»7 

19 
24 

27 

The  costo-marginal  sulci  run  at  a  distance  of  about  20  mm.  below  the  costo-peripheral 
sutures.  On  the  under  side  of  the  nuchal  and  the  first  and  second  peripherals  the  marginal 
scutes  are  28  mm.  wide. 

On  the  visceral  side  of  that  portion  of  the  carapace  present  (fig.  424)  are  exhibited  the 
axillary  and  the  inguinal  buttresses  and  the  shoulders  of  bone  against  which  thev  abut.    The 


Figs.  423-425. — Echmatemys  cyane.     Carapace  and  plastron  of  type.     X  i- 

423.  Portion  of  carapace. 

424.  Portion  of  carapace,  inner  surface,     ax.b.^  axillary  buttress;  c. /».  6,  sixth  costal  plate;   ing.h.y 

inguinal  buttress.     On  the  left  are  seen  some  neurals  and  the  bases  of  the  rib-heads. 

425.  Two  fragments  of  the  plastron. 

axillary  buttress  has  a  maximum  width  of  25  mm.  and  is  12  mm.  thick.  It  ascends  within  the 
first  costal  to  a  point  25  mm.  or  more'above  the  upper  border  of  the  second  peripheral,  consider- 
ably further  than  the  buttress  ascends  in  E.  wyomingensis,  No.  5987  and  No.  5988,  A.  M.  N.  H. 
It  abuts  against  an  extremely  prominent  ridge,  12  mm.  thick  and  10  mm.  elevation  above  the 
general  surface  of  the  costal.  This  buttress  and  ridge  are  therefore  very  different  from  those 
of  the  species  just  mentioned.  The  distance  from  the  upper  end  of  the  buttress  to  the  base  ot 
the  rib-head  is  less  than  the  distance  from  the  summit  of  the  buttress  to  the  border  of  the 
second  peripheral.  In  E.  wyomingensis  the  former  distance  is  much  greater  than  the  latter. 
The  posterior  buttress  articulates  for  a  moderate  distance  against  the  inner  surfaces  ol 
the  fifth  and  the  sixth  costals,  about  as  far  as  in  E.  wyomingensis,  but  it  appears  that  the  but- 


326 


FOSSIL    TURTLES    OF    NORTH    AMKRICA. 


I'lGS.  426  AND  427. — Echmatemys  cyane. 
of  type.     Xi- 


Plastron 


416.  Upper  surface  of  epiplastral  lip. 

427.  Upper  surface  of  left  side  of  hinder  lobe. 


tress  of  the  latter  did  not  project  so  far  from  the  inner  surface  of  the  carapace  and  was  thinner. 
In  E.  luyomingetisis,  as  represented  by  No.  5987,  at  a  point  20  mm.  below  its  summit,  the  but- 
tress projects  inward  from  its  articulation  only  9  mm.;  in  E.  cyane  it  projects  inward  23  mm., 
a  difference  hardly  to  be  regarded  as  merely  individual. 

The  plastron  (fig.  425)  had  a  length  very  close  to  325  mm.  On  account  of  the  absence  of 
some  fragments  which  connected  parts  which  are  present,  the  exact  length  can  not  be  deter- 
mined. The  length  of  the  anterior  lobe 
was  very  close  to  90  mm.;  the  width  was 
not  far  from  130  mm.  The  epiplastral 
lip  has  a  width  of  54  mm.  It  projects 
but  slightly  beyond  the  general  outline 
ofthelobe.  It  is  truncated, with  an  acute 
free  border.  The  lateral  portion  con- 
sists of  a  stout  tooth  separated  from  the 
remainder  of  the  lip  by  a  deep  slit.  On 
the  upper  side  the  thickening  of  the 
epiplastrals  (fig.  426)  extends  backward 
from  the  free  border  a  distance  of  28 
mm.  The  epiplastralsarenowheregreat- 
ly  thickened,  the  maximum  being  1 1  mm. 
The  entoplastron  had  a  length  close  to 
49  mm.,  and  the  width  has  been  56  mm. 
It  is  rounded  in  front  and  behind. 

The  bridge  has  a  width  of  132  mm. 
The  plastral  bones  are  21  mm.  thick  at 
the  crossing  of  the  median  longitudinal 
and  the  hyohypoplastral  sutures. 
The  hinder  lobe  has  a  length  of  1 13  mm.    The  width  appears  to  have  been  about  146  mm. 
The  beveled  surfaces  on  the  upper  side  of  the  lobe  (fig.  427)  have  a  width  of  28  mm.  at  the 
hypoxiphiplastral  sutures,  of  which  width  21  mm.  were  covered  with  horny  scutes.    The  thick- 
ness of  the  bones  at  the  sutures  just  mentioned  is  12  mm. 

The  inguinal  buttresses  send  their  bases  inward  from  the  free  borders  of  the  posterior  lobe 
a  distance  of  about  33  mm.,  almost  half  the  distance  to  the  midline.  Thus  they  extend 
inward  further  than  in  E.  wyomingensis,  but  not  so  far  as  in  some  other  species  of  the  genus. 

The  gulars  have  a  length  of  57  mm.;  the  humerals,  about  55  mm.;  the  pectorals,  55  mm.; 
the  abdominals,  90  mm.;  the  femorals,  about  55  mm.;  the  anals,  about  42  mm.,  all  measured 
at  the  midline.  No  part  of  the  axillary  scute  is  seen,  but  it  failed  by  at  least  28  mm.  of  reaching 
the  fifth  marginal.  It  could  have  joined  the  anterior  end  of  the  fourth  for  only  about  10  mm. 
The  inguinal  scute  lacks  10  mm.  of  reaching  forward  to  the  sixth  marginal. 

It  is  hardly  necessary  to  compare  at  length  this  species  with  E.  shaughnessiana,  which  has 
a  thick  epiplastral  lip  and  a  thick  rounded  free  border  on  the  nuchal;  or  with  E.  tegle,  with 
its  urn-shaped  vertebral  scutes;  or  with  E.  arethusa,  with  its  contracted  epiplastral  lip;  or 
with  E.  naomi,  with  its  urn-shaped  vertebral  scutes  and  sulci  lodged  in  deep  grooves. 

From  E.  wyomingensis  it  differs  in  having  the  inguinal  buttresses  reaching  inward  about 
half-way  to  the  midline,  in  having  the  axillary  buttresses  ascending  nearer  the  neurals,  in 
having  the  epiplastrals  thickened  farther  backward  on  the  upper  side  of  the  symphysis  and  in 
having  wider  vertebral  scutes.  E.  ocyrrho'e  differs  in  having  the  vertebral  scutes,  especially  the 
second,  considerably  wider  and  in  having  the  marginal  scutes  of  the  anterior  half  of  the  shell 
rise  higher  on  the  peripherals.  The  American  Museum  specimen  of  E.  stevensoniana  has 
almost  exactly  the  size  of  that  of  the  present  species,  so  that  comparisons  may  be  readily 
made.  E.  stevensoniana  has  narrower  neurals  and  narrower  vertebral  scutes.  The  plastron  of 
E.  stevensoniana  appears  to  be  thicker  than  that  oi  E.  cyane.  Measured  behind  the  abdomino- 
femoral  sulcus  and  one-third  the  distance  from  the  midline  to  the  free  border,  plastron  of  the 
former  is  8.3  mm.  thick;  of  the  latter  11  mm.  The  axillary  scutes  of  E.  stevensoniana  extend 
backward  to  the  fifth  marginal,  while  in  E.  cyane  they  fall  far  short  of  the  latter  marginal.    In 


EMYDID^. 


1^1 


E.  stevensoniana  the  maximum  thickness  of  the  first  and  second  peripherals  at  their  artic- 
ulation is  14  mm.;  in  E.  cyane,  17  mm. 

E.  cyane  differs  from  E.  haydent  in  the  narrower  inguinal  buttresses,  extending  in  the 
former  hardly  half-way  from  the  free  border  of  the  hinder  lobe  to  the  midline;  in  haydent  more 
than  half-way.  In  E.  cyane  the  thickness  of  the  second  neural  is  1 1  mm.;  in  haydent,  14  mm. 
The  center  of  the  plastron  of  E.  cyane  is  20.5  mm.;  that  of  E.  haydent  is  25  mm.  Probably, 
however,  it  will  not  do  to  rely  too  much  on  the  relative  thickness  of  the  neurals  and  of  the 
plastron.  E.  cyane  has  wider  vertebral  scutes  than  E.  haydent,  and  the  fourth  neural  is 
not  octagonal. 

Echmatemys  shaughnessiana  (Cope). 
Plate  50,  figs.  I,  2;   teit-figs.  428-431. 

Emys  shaughnessiana.  Cope,  Amer.  Naturalist,  xvi,  1882,  p.  992;  Vert.  Tert.  Form.  West,  1884,  pp. 
130,  135,  plate  xxiii,  figs.  3-8. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  448. 

This  species  was  first  mentioned  in  1882,  but  the  only  statement  made  regarding  it  by 
Professor  Cope  is  that  its  bones  are  very  thick.  In  1884  a  description  was  publisht,  illustrated 
by  figures  of  the  carapace.    No  part  of  the  plastron  was  figured.    The  specimen  was  found  in 


,  Figs.  428-431. — Echmatemys  shaughnessiana.     Carapace  and  plastron  of  type. 

428.  Carapace.    Xj.    Parts  restored  are  shown  by  interrupted  lines. 

429.  Plastron.    XJ.  430.  Upper  surface  of  front  lobe  of  plastron.    X^. 

431.  Upper  surface  of  border  of  hinder  lobe  of  plastron.     Xi.  '  • 

the  Bridger  deposits  of  Wyoming,  in  1872,  on  Cottonwood  Creek,  therefore  about  the  middle 
of  stage  B. 

The  type  of  the  species  is  now  in  the  possession  of  the  Museum  of  Natural  History  and 
bears  the  number  1069.  A  further  description  is  here  furnisht  as  well  as  figures  of  both  cara- 
pace and  plastron.  This  is  the  more  to  be  desired,  since  some  of  Professor  Cope's  measure- 
ments are  found  to  be  incorrect. 

Professor  Cope  recognized  that  this  species  resembles  in  many  respects  Dr.  Leidy's 
E.  wyomingensis;   and  he  has  given  what  he  regarded  as  differential  characters.    In  general, 


328 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


he  regarded  the  bones  of  the  carapace,  especially  the  neurals,  as  much  thicker  than  those  of  the 
species  just  mentioned.  It  is  doubtful  if  this  is  a  correct  statement.  His  statement  that  the 
axillary  buttresses  are  thicker  than  those  of  E.  wyomingensis  appears  to  be  true.  The  capitula 
of  the  ribs  are  fully  as  broad  as  those  of  E.  haydeni,  altho  apparently  not  so  thick.  The  periph- 
erals are  about  as  much  recurved  as  those  of  E.  wyomingensis. 

The  following  appear  to  be  characters  distinguishing  this  species  from  E.  wyomingensis: 
The  axillary  buttresses,  and  apparently  also  the  inguinal,  are  thicker;  the  humero-pectoral 
suture  passes  behind  the  entoplastron;  the  femoral  scute  extends  inward  on  the  upper  surface 
of  the  hinder  lobe  of  the  plastron  as  far  as  the  inner  border  of  the  inguinal  buttress;  the 
anterior  border  of  the  carapace  has  a  much  more  obtuse  edge;  the  free  border  of  the  epiplastron 
is  thicker  and  more  obtuse;  and  the  smooth  band  on  the  upper  surface  of  the  hinder  lobe  is 
much  wider,  as  is  also  the  thickening  on  the  upper  side  of  the  epiplastral  lip. 

From  the  type  of  £.  shaughnessiana  there  are  missing  the  nuchal  bone,  except  a  fragment; 
the  eighth  neural;  both  suprapygals;  all  the  peripherals  over  both  bridges,  except  a  part  of  the 
right  fourth;  some  of  the  free  peripherals  of  the  left  side  and  the  seventh  of  the  right  side; 
the  distal  ends  of  two  left  costals;  the  left  half  of  the  plastral  lip;  and  parts  of  the  bridge. 
The  forms  of  the  nuchal,  the  eighth  neural,  and  the  suprapygals  and  pygal  can  be  quite  accur- 
ately determined  from  the  surrounding  bones,  so  that  from  one  side  or  the  other  of  the  shell  we 
have  the  means  of  determining  nearly  all  the  elements. 

The  total  length  of  the  carapace  (plate  50,  fig.  i ;  text-fig.  428),  in  a  straight  line,  is  352 
mm.  Cope's  measurement  of  380  mm.  includes  the  curve.  The  width  was  approximately  270 
mm.  Near  the  midline  in  front  the  outline  has  been  gently  concave;  the  posterior  margin  has 
been  broad  and  rounded. 

The  table  herewith  presents  the  dimensions  of  the  nuchal,  neurals,  and  suprapygals. 
The  third  neural  has  a  thickness  of  15  mm.;  the  third  costal  at  its  outer  end  is  7  mm.  thick. 

The  costals  show  no  remarkable  peculiarities.    The  second 
is  only  28  mm.  wide  at  its  proximal  end;  46  mm.  at  its  distal 
end  and  8  mm.  thick  near  the  border  of  the  vertebral  scute. 
The  fifth  and  sixth  of  the  left  side  are,  as  an  individual  pecu- 
liarity, co-ossified  proximally  and  measure  together  only  47 
mm.;  whereas  the  corresponding  ones  of  the  other  side  are 
distinct  from  each  other  and  measure  59  mm.     The  periph- 
erals resemble  those  of  E.  wyomingensis,  but  the  anterior 
are  higher  and  far   less   acute.     The   posterior   are   acute. 
However,  they  are  not  gradually  thinned  out,  as  are  those 
of  E.  wyomingensis,  but  come  rather  abruptly  to  an  edge. 
Cope's  figure  (Tert.  Vert.,  plate  xxiii,  fig.  6)  represents  this 
condition  only  moderately  well.    The  first  peripheral  is  12.5 
mm.  thick  where  it  joins  the  nuchal.    The  second  is  45  mm. 
high;   its  free  border  is  37  mm.  long.    The  third  is  50  mm.  high  and  44  mm.  along  the  free 
border.     On  these  the  marginals  ascend  about  24  mm.  above  the  free  border  of  the  bones. 
Cope's  figure  of  the  carapace  represents  the  seventh  right  peripheral  as  present;   but  it  is 
not  now  in  the  collection.    The  corresponding  one  of  the  left  side  is  present. 

The  width  of  the  first  costal  bone  is  60  per  cent,  of  the  length  along  the  hinder  border. 
The  scutes  of  the  carapace  are  rather  broad  and  their  lateral  sulci  are  bracket-shaped.  The 
nuchal  is  missing.     The  table  below  gives  the  dimensions  of  the  vertebral  scutes. 
The  upper  borders  of  the  marginal  scutes  run  consid- 
erably below  the  sutures  between  the  costal  and  peripheral 
bones.     All    the   scutal   sulci   are   narrow,    but    sharply 
imprest. 

The  plastron  (plate  50,  fig.  2;  text-fig.  429)  has  a  total 
length  of  342  mm.,  falling  short  of  the  length  of  the  cara- 
pace only  10  mm.  In  the  midline  the  length  is  13  mm. 
less,  on  account  of  the  notch.  The  anterior  lobe  is  97 
mm.  long  and,  at  the  base,  is  144  mm.  wide.  The  lip,  as 
seen  from  below,  and  measured  from  one  gular  suture  to 


Element. 

Length . 

Width. 

Nuchal 

Neural  i 

Neural  i 

5» 
28 

71 
^3 
25 

Neural  3 

Neural  4 

Neural  5 

Neural  6 

38 
3^ 
3» 
21 

26 

24 

29 

28 

Neural  7 

Neural  8 

3» 
20 

^3 
28 

Suprapygal   1 . . 
Suprapygal  2 . . 

}     '^ 



I     70 

Dimensions  of  vertebrals 

Width 

Greatest 

Scute. 

Length. 

in  front. 

width. 

Vertebral  1 . . 

55± 

68 

68 

Vertebral  2.. 

60 

37 

S8 

Vertebral  3 . . 

71 

39 

58 

Vertebral  4. . 

7S± 

45 

65 

Vertebral  5.. 

62  ± 

36 

96 

EMYDIDit. 


329 


the  other,  is  56  mm.  wide.  A  notch  in  the  border  produces  a  blunt  tooth  on  each  side. 
Beyond  the  notch  the  general  curvature  of  the  lobe  is  continued  on  to  the  midline.  It  remains 
to  be  seen  whether  this  character  will  persist  in  additional  specimens.  Seen  from  above  (fig. 
430),  the  lip  is  66  mm.  wide  from  one  gular  suture  to  the  other,  and  continues  backward  32 
mm.  The  entoplastron  is  diamond-shaped,  55  mm.  long,  65  mm.  wide  and  1 1  mm.  thick.  It 
supports  the  hinder  portion  of  the  gular  scutes,  but  no  part  of  the  pectoral  scutes. 

The  hyoplastra  occupy  72  mm.  of  the  midline;  the  hypoplastra,  93  mm.;  the  xiphiplastra, 
78  mm.  The  hinder  lobe  of  the  plastron  is  107  mm.  long;  its  width  at  the  base  is  145  mm. 
The  upper  surface  of  the  hypoplastron  (fig.  431)  behind  the  inguinal  buttress  was  covered 
with  horny  epidermis  as  far  inward  as  the  buttress  extends,  31  mm.  In  all  accessible  specimens 
of  E.  luyomingensis  this  surface  is  much  narrower.  The  inner  edge  of  the  inguinal  buttress 
arises  from  the  floor  of  the  plastron  at  a  line  not  half-way  from  the  free  border  of  the  lobe  to 
the  midline,  resembling  in  this  respect  E.  wyomingensis. 

The  gular  scutes  extend  along  the  midline  42  mm.;  the  humerals,  42  mm.;  the  pectorals, 
42  mm.;   the  femorals,  56  mm.;    the  anals,  55  mm. 

The  species  differs  from  all  others  of  the  genus,  so  far  as  known,  in  having  the  humero- 
pectoral  sulcus  cross  behind  the  entoplastron. 


Figs.  432-435. — Echmatemys  ocyrrhoii.     Portions  of  type. 

432.  Carapace.    X}.  433.  Plastron.    Xj. 

434.  Upper  surface  of  anterior  lobe  of  plastron.    X^. 

435.  Upper  surface  of  inguinal  region  of  plastron,  showing  base  of 

inguinal  buttress  and  free  border  of  hinder  lobe.     X^. 

Echmatemys  ocyrrhoe  sp.  nov. 

Figs.  431-435. 

Two  specimens  in  the  American  Museum  of  Natural  History  represent  this  species.  No. 
5933  and  No.  5954.  Of  these,  No.  5933  is  taken  as  the  type.  It  was  collected  in  1903  by  Mr. 
Walter  Granger  in  the  Bridger  Eocene  beds  at  Church  Buttes,  Wyoming.  No.  5954  was 
collected  by  the  writer  in  1903,  in  the  western  portion  of  Grizzly  Buttes,  Wyoming.  Both 
specimens  therefore  come  from  the  lower  part  of  the  horizon  B  of  the  Bridger  beds,  the  speci- 
men from  Church  Buttes  belonging  probably  to  a  slightly  lower  level. 

No.  5933  presents  the  shell  nearly  complete.  The  second  suprapygal,  most  of  the  pygal, 
the  eleventh  peripheral  of  the  right  side  and  the  distal  ends  of  the  eighth  pair  of  costals  are 
wanting.  No.  5954  furnishes  the  plastron  backward  as  far  as  the  hypoxiphiplastral  suture 
and  various  portions  of  the  carapace,  including  the  hindermost  peripherals,  but  not  the  pygal- 


330 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


The  type,  No.  5933,  measures,  from  the  front  of  the  plastron  to  the  rear,  280  mm.     The 
length  of  the  carapace  (fig.  4^2)  is  302  mm.     The  width  in  a  straight  line  is  223   mm.,  thus 

being  74  per  cent,  of  the  length.  The  shell  has 
been  little,  if  any,  crusht  downward,  and  the 
height  is  now  108  mm.  The  front  is  slightly 
incurved  in  front.  The  anterior  border  is  sub- 
acute, and  the  anterior  peripherals  thicken  rap- 
idly.   The  surface  of  the  shell  is  smooth. 

The  neurals  are  rather  broad,  having  the 
dimensions  shown  in  the  table  herewith. 

The  nuchal  is  48  mm.  long,  37  mm.  wide 
at  the  free  border,  and  63  mm.  where  widest. 
The  costal  plates  behind  the  first  pair  are 
differentiated  so  that  the  proximal  ends  are 
alternately  narrower  and  wider,  while  the  distal 
ends  are  alternately  wider  and  narrower.  The  dimensions  of  the  costal  plates  are  given  in 
the  table  above. 

The  table   below  shows  the   dimensions   of  the   peripherals,  the   vertebral  scutes,  and 
the  marginals. 

The  height  of  the  third  peripheral  is  only  44  per  cent,  of  the  height  of  the  first  costal  near 
its  hinder  border.    The  width  of  this  costal  is  70  per  cent,  of  its  height. 

The  nuchal  has  a  length  of  14  mm.  and  a  width  of  13  mm.    The  vertebral  scutes,  except 
the  first,  are  of  moderate  width. 


Dimensions  of  neurals. 

Dimensions  of  costal  bones. 

Width 

Width 

No. 

Length. 

Width. 

No. 

of  proxi- 

of distal 

I 

^ 

mal  end. 

end. 

37 

»4 

29 

35 

2 

19 

28 

3 

31 

^S 

3 

30 

26 

4 

IS 

40 

4 

28 

^5 

s 

33 

18 

S 

Z9 

22 

6 

21 

35 

6 

ZI 

28 

7 

>9 

»5 

7 

18 

26 

8 

12 

16.S 

Dimensions  of  peripherals. 

Width       Width 

No. 

Height. 

of  free 

of  upper 

34 

border. 

border. 

I 

35 

17 

z 

3i 

35 

18 

3 

34 

37 

3i 

6 

38 

39 

37 

8 

43 

36 

''       i 

1 

Dimensions  of  vertebral  scutes. 


No.      Length. 


57 
57 
61 
66 
5° 


Width 
ante- 
riorly. 

80 
45 
58 
41 
34 


Greatest 
width. 


So 
61 

53 
58 


Dimensions  of  marginals. 


No. 


Height  j  Greatest 


in  froot. 


■4 

»3 
20 
20 
30 
33 


height. 


»3 
26 
20 
22 
33 
37 


Length 
at  free 
border. 


3» 
33 
33 
37 
37 
36 


The  anterior  lobe  of  the  plastron  (fig.  433)  has  a  length  of  76  mm.,  and  a  width  of  113  mm., 
at  the  base.  The  borders  continue  straight  forward  to  the  suture  between  the  hyoplastron  and 
the  epiplastron,  then  curve  toward  the  lip.  The  latter  is  49  mm.  wide,  truncated  and  provided 
with  a  short  stout  tooth  on  each  side.  It  extends  as  far  in  front  as  the  border  of  the  nuchal. 
The  greatest  thickness  of  the  epiplastral  bones  is  13  mm.  The  thickening  on  the  upper  surface 
(fig.  434)  extends  backward  24  mm.  The  horn-covered  surface  is  18  mm.  wide,  becoming 
reduced  to  16  mm.  at  the  hyoepiplastral  suture.  The  entoplastron  is  47  mm.  long  and  53  mm. 
wide.  The  anterior  buttresses  ascend  only  about  one-third  the  distance  from  the  lower  to  the 
upper  border  of  the  first  costals. 

The  bridge  has  a  width  of  118  mm.  The  hypoplastrals,  in  the  midline,  just  behind  the 
suture  with  the  hyoplastrals,  are  13  mm.  thick.  This  is  reduced  very  little  toward  the  anterior 
and  the  posterior  buttresses. 

The  hinder  lobe  has  a  length  of  90  mm.  and  a  width  of  126  mm.  The  buttresses  are 
broad.  The  beveled  surface  (fig.  435)  on  the  upper  side  of  the  hinder  lobe  is  of  only  moderate 
width,  19  mm.  at  the  suture  with  the  xiphiplastral.  The  posterior  notch  appears  to  have  been 
rather  shallow. 

The  gular  scutes  are  40  mm.  long;  the  humerals,  33  mm.;  the  pectorals,  48  mm.;  the 
abdominals,  73  mm.;  the  femorals,  38  mm.;  the  xiphiplastrals,  at  the  midline,  45  mm.  The 
axillary  scutes  are  quadrilateral  and  fail  by  15  mm.  of  extending  backward  to  the  fifth  marginals. 
The  inguinals  lack  the  same  distance  of  reaching  to  the  sixth  marginals. 

No.  5954  is  of  almost  exactly  the  same  size  as  No.  5933,  the  length  of  the  plastron  to  the 
hypoxiphiplastral  suture  being  218  mm.    It  varies  in  slight  degrees  from  the  type.    The  neurals 


EMYDID^. 


331 


present  are  a  little  narrower,  as  are  also  the  vertebral  scutes.  The  greatest  thickness  ot  the 
nuchal  bone  is  16  mm.  The  ninth  peripheral  is  48  mm.  high,  35  mm.  wide  at  the  free  border 
and  23  mm.  wide  at  the  upper  border.  Its  greatest  thickness  is  13  mm.  This  and  the  other 
hinder  peripherals  thin  out  to  an  acute  border.  The  pygal  is  missing  but  the  eleventh  periph- 
erals show  that  it  had  a  height  of  23  mm.  and  that  its  right  and  left  sides  were  convex.  The 
heads  of  the  ribs  of  these  specimens  had  a  diameter  of  8  mm. 

The  plastron  differs  in  having  a  slightly  narrower  anterior  lobe,  108  mm.,  a  narrower 
hinder  lobe,  117  mm.,  and  a  narrower  lip,  41  mm.  The  entoplastron  is  38  mm.  long  and 
50  mm.  wide.  In  both  specimens  the  anterior  lobe  is  very  short  in  proportion  to  its  width, 
being  only  67  per  cent,  thereof. 

The  respects  in  which  this  species  differs  from  E.  cegle  are  stated  under  the  species  just 
named.  E.  septarta  differs  in  the  expanded  anterior  lobe,  in  the  greatly  thickened  epiplastral 
bones,  and  in  the  contracted  lip.  The  acute  or  subacute  anterior  border  of  the  carapace  of 
E.  ocyrrhoe  distinguishes  it  from  E.  shaughnessiana. 

E.  ocyrrhoe  differs  from  E.  haydeni  in  having  the  first  vertebral  scute  much  broader  in 
front  and  rapidly  narrowing  posteriorly.  The  other  scutes  are  as  broad  as  long  or  nearly  so; 
while  in  E.  haydeni  they  are  much  longer  than  broad.  E.  stevensoniana  is  a  relatively  narrower 
shell,  the  width  being  only  a  little  over  two-thirds  of  the  length;  and  more  pointed  in  front  and 
behind.  The  anterior  border  of  £.  stevensoniana  is  more  acute  than  in  E.  ocyrrhoe  and  the 
suture  between  the  first  and  second  peripherals  is  14  mm.  thick,  instead  of  16.5  mm.  The 
epiplastral  lips  of  the  two  species  are  different.  Comparisons  with  E.  cyane  are  to  be  found 
under  the  latter  species. 

Echmatemys  aegle   sp.  nov. 
Figs.  436-441 . 

Two  specimens  represent  at  present  this  species.  These  were  obtained  in  the  Bridget  beds, 
near  Bridger,  Wyoming,  in  1903.  Of  these,  one,  No.  5909  of  the  American  Museum  of  Natural 
History,  is  made  the  type.  The  locality  where  obtained  is  the  western  portion  of  Grizzly  Buttes 
and  the  level  is  the  lower  portion  of  horizon  B. 

The  specimen  is  represented  by  the  complete  plastron,  the  anterior  5  pairs  of  costal  plates, 
the  sixth  costal  plate  of  the  right  side,  and  a  few  peripherals.  The  nuchal  bone  is  missing. 
An  estimate  based  on  the  plastron  makes  it  probable  that  the  carapace  had  a  length  ot 
330  mm.  The  surface  is  smooth,  except  for  some  longitudinal  striations  on  the  neural  bones. 
The  sulci  bounding  the  epidermal  scutes  are  rather  deeply  and  uniformly  imprest.  The  tables 
below  give  the  dimensions  of  the  neurals  and  of  the  vertebral  scutes,  so  far  as  presented. 

There  is  little  difference  as  respects 
width  between  the  proximal  and  the 
distal  ends  of  the  costal  plates. 

The  first  right  peripheral  is  repre- 
sented by  that  portion  in  front  of  the 
costo-marginal  sulcus.  Its  free  border 
is  acute  at  the  end  next  the  nuchal  bone 
but  rather  obtuse  at  the  end  next  to  the 
second  peripheral.  The  extent  of  the 
free  border  is  38  mm.  The  greatest 
height  of  the  second  marginal  scute  was 
about  29  mm.  The  greatest  thickness 
of  the  bone  is  12  mm.  A  part  of  the  right  third  peripheral  is  present  and  will  be  referred  to 
below.  The  fifth  peripheral  is  present  and  shows  an  angular  ridge,  along  which  the  upper  side 
of  the  shell  past  abruptly  into  the  lower  side.  This  peripheral  rises  above  the  ridge  mentioned 
a  distance  of  35  mm.  and  it  has  a  width  of  40  mm.  The  seventh  peripheral  has  a  length  ot 
40  mm.  along  the  free  border.  Its  upper  border  is  broken  away.  The  maximum  thickness 
of  the  end  articulating  with  the  eighth  is  13  mm.,  but  it  may  have  suffered  some  compression. 
The  eighth  peripheral  measures  33  mm.  along  the  free  border  and  it  rises  to  a  height  of  45  mm. 
The  vertebral  scutes  are  broad  and  urn-shaped,  quite  hke  those  of  £.  naomi.  The  table 
above  gives  the  dimensions. 


Dimensions  of  neurals. 

Dimensions  of  vertebrals. 

No. 

Length.     Width. 

No. 

T      _!.      Width     Greatest 

I 

40             26 

I 

82±              82± 

2        I       30      ,       27 

2 

66 

4^             75 

3 

34             »8 

3 

68 

40             66 

4 

30 

27 

4 

45           70 

S 

30 

27 

6 

20 

29 

1 
i                 ■ 

332 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


As  shown  by  the  fifth,  seventh,  and  eighth  peripherals  the  costo-marginal  sulci  ran  near  the 
costo-peripheral  sutures,  being  distant  8  mm.  or  less. 

As  stated  previously,  the  plastron  (fig.  436)  has  a  total  length  of  300  mm.  The  anterior 
lobe  measures  87  mm.  in  length  and  has  a  width  of  124  mm.,  the  length  thus  being  70  per  cent, 
of  the  width.  It  contracts  a  little  in  front  of  the  axillary  notch,  then  runs  directly  forward  some 
distance  in  front  of  the  hyoepiplastral  sutures,  then  curves  rapidly  to  the  lip.  The  latter  is 
49  mm.  wide,  (^n  each  side  it  presents  a  stout  tooth.  Behind  these  teeth  the  thickness  of  the 
bones  is  1 1  mm.  The  thickened  portion  of  the  epiplastral  (fig.  437)  continues  backward  26  mm. 
Outside  of  the  gular  sutures,  on  the  upper  side,  the  horn-covered  surface  is  18  mm.  wide, 
increases  to  20  mm.,  and  is  reduced  at  the  hyoepiplastral  suture  to  16  mm.  The  entoplastron  is 
35  mm.  long  and  60  mm.  wide.  The  anterior  buttresses  arise  some  15  mm.  or  more  within  the 
border  of  the  anterior  lobe  and  rise  to  a  height  of  at  least  63  mm.  They  are  about  30  mm. 
wide  and  7  mm.  thick.    The  width  of  the  bridge  is  132  mm. 


436. 


Figs.  436-438. — Echmatemys  legle.     Plastron  of  type. 

4^6.  Plastron.    X^.  437.  Upper  surface  of  anterior  lobe.    X^. 

438.  Upper  surface  of  hinder  lobe  of  plastron.    X^. 

The  hinder  lobe  is  90  mm.  long  and  126  mm.  wide  at  the  base,  the  length  being  thus  71  per 
cent,  of  the  width.  It  is  rather  conspicuously  notcht  at  the  outer  ends  of  the  femoro-anal  sulci. 
The  notch  in  the  rear  is  rather  deep,  13  mm.,  and  its  width  is  36  mm.  The  beveled  area  on  the 
upper  side  of  the  hinder  lobe  (fig.  438)  commences  near  the  outer  border  of  the  buttress, 
increases  in  width  to  the  hypoxiphiplastral  suture,  where  it  is  23  mm.  wide,  and  then  diminishes 
to  10  mm.  The  bases  of  the  posterior  buttress  extend  more  than  half-way  from  the  border  ot 
the  hinder  lobe  to  the  midline.  Their  summits  are  fully  65  mm.  above  the  upper  surface  of  the 
hinder  lobe.      They  are  25  mm.  or  more  wide  and  7  mm.  thick  at  half  their  height. 

The  gulars  have  a  length,  on  the  midline,  of  47  mm.;  the  humerals,  22  mm.;  the  pectorals, 
58  mm.;  the  abdominals,  72  mm.;  the  femorals,  47  mm.;  the  anals,  34  mm. 

The  portions  of  the  third  and  fourth  peripherals  present  show  that  the  axillary  scutes  tail 
to  reach  the  fifth  marginal  scute  by  20  mm.    The  inguinal  scutes  are  not  well  displayed. 

A  second  specimen  referred  to  this  species  is  No.  5976  of  the  American  Museum.  It  was 
obtained  in  1903,  in  the  western  portion  of  Grizzly  Buttes  and  in  level  B.    It  is  represented  by 


EMYDID^. 


333 


the  anterior  three-fourths  of  the  shell.    It  had  almost  exactly  the  same  size  as  the  preceding 
specimen,  the  length  from  the  front  of  the  carapace  to  the  xiphiplastron  being  233  mm.    The 

specimen  has  been  considerably  crusht  down- 
ward. It  furnishes  the  whole  front  of  the  cara- 
pace (fig.  439),  most  of  which  was  wanting  in 
the  type.  The  nuchal  has  a  maximum  width  of 
82  mm.,  but  this  would  be  less  if  the  bone  were 
archt  as  usual.  The  free  border  of  the  bone 
measures  39  mm.  The  front  border  of  the  cara- 
pace is  very  acute  to  the  beginning  of  the  second 
peripheral.  The  accompanying  table  shows  the 
dimensions  of  the  neurals. 

The  costal  plates  of  this  specimen  are  modi- 
fied more  than  those  of  the  type.  The  widths  of  the  ends  are  given  in  the  table  above. 
The  width  of  the  first  costal  is  equal  to  65  per  cent,  of  its  height  near  the  hinder  border. 

The  dimensions  of  some  of  the  peripherals  and  of  the  vertebral  and  marginal  scutes  are 
shown  below  in  tabular  form. 

The  maximum  thickness  of  the  nuchal  and  the  first  peripheral  at  their  suture  is  12  mm. 


1     Dimensions  of  neurals. 

Dimensions  of  costals. 

I 
Neural. 

Length. 

Width. 

„    .  ,     Proximal 
|C'»'»'-       width. 

Distal 
width. 

I 
2 
3 
4 

5 

38 
3» 
36 
3» 

32± 

»3 
i7 
26 

27 
28 

2  32 

3  39 

4  29 

5  3° 

6  20 

4> 
26 

38 
^3 
34 
1 

Dimensions  of  peripherals. 

Dimensions  of  vertebrals. 

Dimensions  of  marginals. 

No. 

Width 

Height.  [  of  free 

border. 

Width     "                                    ..,,,, 
of  upper       No.      Length,    j^  j^^_^^ 
border,  j,              |                 , 

Greatest 
width. 

J,          Height    Greatest 
in  front,    height. 

Length 
of  free 
border. 

I 
2 
3 

4 

40 
38 
39 
36 

35 
37 
40 
4' 

«>      '      I            55           79 
19            2           65           39 
28             3            68            38 
38             4            ••       ,      +5 

79 
70 
67 
8o± 

I 

2 

19  24 
23       1       28 

20  21 

21  2S± 

3' 
35 
40 
35 

The  first  and  second  peripherals  are  12  mm.  thick  at  their  articulation.    The  maximum  thick- 
ness of  the  hinder  articular  end  of  the  seventh  neural  is  15  mm. 

The  vertebral  scutes  resemble  those  of  the  type.      The  nuchal  scute  is  17  mm.  long,  10 

mm.  wide  in  front,  expanding  to  18  mm.  behind.  The 
marginal  scutes  have  the  dimensions  given  in  the  table 
above. 

The  surface  of  the  carapace  is  smooth,  except  that 
on  the  neurals  and  proximal  ends  of  the  costals  there  are 
fine  longitudinal  striations. 

From  the  plastron  the  xiphiplastrals  are  missing. 
The  length  of  the  anterior  lobe  is  82  mm.;  the  width 
of  the  base  is  130  mm.  The  length  is  therefore  only  63 
per  cent,  of  the  width.  It  is  possible  that  this  is  a  sexual 
difference,  the  lobes  of  the  type  being  somewhat  narrower. 
The  width  of  the  epiplastral  lip  is  54  mm.  The  upper 
surface  of  the  front  of  the  lobe  resembles  that  of  the  type, 
except  that  there  is  a  broad  channel  on  each  side  of  the 
midline,  extending  out  to  the  lateral  tooth.  The  horn- 
covered  areas  of  the  upper  surface  resemble  those  of  the 
type.    The  bridge  is  130  mm.  wide. 

The  hinder  lobe  is  141  mm.  wide.  It  will  be 
observed  that  both  the  anterior  and  the  posterior  lobes 
are  wider  than  those  of  the  type.  The  beveled  surface  on 
the  upper  side  of  the  hinder  lobe  is  25  mm.  wide. 

The  gulars  have  a  length  of  40  mm.;  the  humerals, 
23  mm.;  the  pectorals,  64  mm.;  the  abdominals,  79  mm.  The  axillary  scutes  fail  of  reaching 
the  fifth  marginal  by  14  mm.  The  inguinal  scutes  extend  forward  so  as  barely  to  meet  the 
sixth  marginals. 


F"iG.  439. — Echmatemys  agle.     Cara- 
pace.   X  i-    No.  5976  A.  M.  N.  H. 


334 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


This  species  appears  to  be  most  closely  related  to  E.  ocyrrho'e.  In  E.  <egle,  as  compared 
with  E.  ocyrrho'e  the  vertebral  scutes  are  wider  and  more  distinctly  urn-shaped,  the  neurals  are 
broader,  the  carina  over  the  bridge,  on  the  peripherals,  appears  to  have  been  more  angular, 
the  beveled  areas  on  the  upper  side  ot  the  epiplastron  are  somewhat  wider;  those  on  the  upper 
side  of  the  hind  lobe  are  considerably  wider.  The  front  border  of  the  carapace  of  E.  cegle  is 
more  acute  and  the  bones  are  not  so  thick.  As  shown  by  the  specimens,  the  eighth  peripheral 
of  £.  (tgle  is  only  12  mm.  thick  where  it  joins  the  seventh,  whereas  in  E.  ocyrrho'e  it  is  \J  mm. 
thick.  In  the  second  specimen  of  £.  <egle  the  thickness  of  this  bone  is  15  mm.  In  E.  ocyrrho'e 
the  inguinal  scutes  did  not  reach  the  sixth  marginals.  As  compared  with  E.  ocyrrho'e,  No. 
5954,  the  rib-heads  are  much  stouter,  the  diameters  of  the  former  being  about  10  mm.;  in  the 
latter  about  8  mm.  The  thickness  of  the  first  costal  plate  at  the  angle  where  it  joins  the  nuchal 
and  the  first  peripheral  is  9  mm.  thick  in  E.  cegle,  11  mm.  in  E.  ocyrrho'e.  No.  5954;  the  latter 
being,  besides,  a  smaller  individual.  In  E.  agle.  No.  5976,  the  thickness  of  peripherals  one  and 
two  at  their  articulation  is  12  mm.;    in  E.  ocyrrho'e,  17.5. 

E.  cegle  resembles  E.  naomi  in  the  form  of  the  vertebral  scutes,  but  is  distinguisht  there- 
from by  numerous  characters. 

No.  10073  of  the  paleontological  collection  of  Princeton  University  appears  to  belong  to  this 
species.    Its  length  is  close  to  300  mm.,  the  width,  215  mm.    The  center  of  the  carapace  is 


440. 


Figs.  440  and  441. — Echmatemys  eegle.     Carapace  and  plastron.     Xi-     No.  11515 

Princeton   University. 

440.  Carapace.  441.  Plastron. 

missing,  removing  most  of  the  neurals  and  vertebral  scutes.  The  first  vertebral  is  55  mm. 
long,  78  mm.  wide  in  front,  36  mm.  behind.  The  fourth  vertebral  is  70  mm.  wide  where 
widest — contracting  behind  to  27  mm.    The  fifth  had  a  maximum  width  of  64  mm. 

The  anterior  lobe  of  the  plastron  contracts  very  little  from  the  axillary  notches  to  the 
hyoepiplastral  suture;  then  rapidly  to  the  lip.  There  is  a  sharp  notch  at  each  side  of  this. 
No.  1 1515  (figs.  440,  441)  of  Princeton  University,  lacking  the  hinder  part  of  the  shell,  appears 
to  belong  here.  The  nuchal  scute  is  80  mm.  wide  near  the  front,  narrows  to  64  mm.,  widens 
again  to  70  mm.,  then  narrows  to  43  mm.  at  the  hinder  end.  The  other  vertebrals  are  expanded 
at  the  middle  of  the  length.  The  sulci  are  deeply  imprest.  The  length  from  the  front  of  the 
carapace  to  the  hinder  border  of  the  sixth  neural  is  255  mm.  The  axillary  and  the  inguinal 
buttresses  are  strongly  developt,  rising  high  on  the  inside  of  the  carapace.  The  former  extends 
inward  from  the  free  border  of  the  anterior  lobe  about  25  mm.  The  inguinal  buttresses  extend 
inward  from  the  free  border  of  the  hinder  lobe  32  mm.  They  articulate  with  the  fifth  and 
sixth  costals. 


EMYDID^. 


335 


Element. 


Length.    Width. 


Nuchal 

Neural  i 

Neural  2 

Neural  3 

Neural  4 

Neural  5 

Neural  6 

Neural  7 

Neural  8 

Suprapygal    i . 
Suprapygal   2. 

Pyg»i 


Echmatemys  naomi  sp.  nov. 
Plate  51,  figs.  I,  2;   teit-figs.  442-444. 

The  type  of  the  present  species  is  a  finely  preserved  shell  which  was  collected  by  the 
American  Museum  expedition  of  1903,  in  the  Bridger  beds  of  Wyoming.  The  locality  is 
Little  Dry  Creek,  near  the  western  part  of  Grizzly  Buttes  and  the  level  is  the  lower  part  of 

horizon  B.  The  shell  has  suffered  slight  downward  crushing, 
but  none  of  the  characters  have  thereby  been  obscured.  The 
number  of  the  specimen  is  5975. 

The  total  length  of  the  carapace  (plate  51,  fig.  i;  text-fig. 
442)  is  360  mm.  The  width  taken  across  the  middle  is  263 
mm.,  and  this  is  the  greatest  width.  The  front  of  the  shell  is 
in  no  way  contracted.  The  hindermost  peripherals  appear  to 
have  been  slightly  notcht  at  the  sutures.  The  table  gives  the 
dimensions  of  the  central  row  of  bones. 

The  width  of  the  free  border  of  the  nuchal  is  42  mm.  The 
costals  present  little  that  is  novel.  The  proximal  ends  are 
usually  of  nearly  the  same  width  as  their  distal  ends,  except  that 
the  last  three  have  their  distal  ends  expanded  somewhat. 

The  table  below  presents  the  dimensions  of  some  of  the 
peripherals.  The  height  of  the  third  peripheral  is  53  per  cent,  of  the  hinder  border  of  the 
first  costal. 

The  nuchal  and  the  first  pair  of  peripherals  have  an  acute  free  border.  The  greatest  thick- 
ness of  the  first  is  19  mm.  The  free  border  of  the  second  is  subacute  and  passes  into  the 
rounded  free  border  of  the  third. 


55 
47 
43 
33 
3* 
33 
26 
20 
17 
3' 
37 
3' 


70 
28 
33 
33 
33 
3' 
»9 
29 

34 

70 

39 


Dimensions 

of  peripherals. 

Dimensions  ol 

marginal  scutes. 

Dimensions 

of  vertebral  s. 

No. 

Height. 

Width 
of  free 
border. 

Width 
of  costal 
border. 

No. 

Height 
in  front. 

„      .    _    Length 
Greatest          , 
...         at   free 

'«='«'''•     border. 

No.      Length. 

Width  at 

anterior 

end. 

Greatest 
width. 

I 

4* 

34 

14 

I 

20 

»S       1      33 

63 

81 

81 

2 

4» 

35 

20 

» 

»4 

28             32 

2             70 

42 

74 

3 

43 

41 

17 

3 

22 

23          !          38 

3              70 

43             70 

6 

46 

48 

43 

4            ii 

28                   45 

4            68 

48             71 

8     1      5- 

1 

43 

3^ 

9            36 

38                   40 

5           6, 

31             79 

The  posterior  peripherals  are  flared  moderately  upward.  They  are  rather  thin  and  pass 
out  into  a  sharp,  thin,  free  border.  The  thickness  of  the  ninth  at  the  longitudinal  sulcus  is 
9  mm. 

The  first  costal  is  four-fifths  as  wide,  fore  and  aft,  as  it  is  long  on  the  hinder  border. 

The  upper  surface  of  the  shell  is  very  uneven.  Large  parts  of  the  sulci  run  in  very  deep 
grooves.  Between  them  the  surface  is  usually  rough  and  pitted.  There  is  no  keel.  In  the 
middle  of  the  nuchal  there  is  a  slight,  broad,  rounded,  longitudinal  elevation  and  a  similar  one 
on  the  suprapygals  and  pygal.  The  sulcus  running  around  the  carapace  on  the  nuchal,  the 
peripherals,  and  the  second  suprapygal,  lies  in  a  deep  groove.  This  groove  has  so  weakened 
the  peripherals  in  its  course  that  the  pressure  has  caused  them  to  yield  along  this  sulcus.  The 
sulci  between  costals  i  and  2  and  between  2  and  3  lie  in  very  deep  grooves,  especially  at  their 
upper  ends.  The  hinder  ends  of  the  sulci  bounding  laterally  the  three  anterior  vertebral  scutes 
lie  in  deep  and  broad  grooves.  The  sulci  between  many  of  the  marginal  scutes  occupy 
deep  grooves. 

The  nuchal  has  a  length  of  19  mm.  and  a  width  of  15  mm. 

The  dimensions  of  marginal  scutes  are  shown  in  the  table  above. 

The  costo-marginal  sulci  run  far  below  the  costo-peripheral  sutures. 

The  vertebral  scutes  are  broad  and  rather  strongly  urn-shaped;  their  dimensions  are  pre- 
sented in  the  table  above. 

The  plastron  (plate  51,  fig.  2;  text-fig.  443)  has  a  total  length  of  326  nmi.  The  front 
extends  somewhat  beyond  the  border  of  the  carapace.    The  length  of  the  anterior  lobe  is  96 


33^ 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


mm.;  its  width  128  mm.  The  length  then  has  a  high  ratio  to  the  width,  being  75  per  cent, 
thereof.  The  lateral  border  runs  nearly  straight  to  a  point  some  distance  in  front  of  the  hyo- 
epiplastral  suture,  then  rounds  rapidly  to  the  lip.  The  lip  is  53  mm.  wide.  It  projects  little 
and  is  furnisht  with  a  right  and  a  left  lateral  tooth  and  2  closely  placed  median  teeth.  Between 
the  lateral  tooth  and  the  midline  the  upper  surface  of  this  lip  is  considerably  excavated.  The 
thickening  of  the  epiplastrals  on  the  upper  surface  (fig.  444)  extends  backward  30  mm.  The 
greatest  thickness  of  these  bones  is  12  mm.  The  median  space  between  these  thickenings  on 
the  upper  surface  is  somewhat  excavated.  The  free  borders  of  the  lobe  are  acute  nearly  to 
the  lip.  The  beveled  surface  on  the  upper  side  of  the  epiplastrals  has  a  width  of  only  12  mm. 
at  the  hyoepiplastral  suture.  The  entoplastron  is  50  mm.  long  and  60  mm.  wide.  The  bridge 
has  a  width  of  137  mm.  The  hinder  lobe  is  98  mm.  long  and  143  mm.  wide  at  the  base.  The 
length  of  the  lobe  equals  therefore  about  69  per  cent,  of  the  width.  There  is  a  rather  broad 
notch  at  the  rear  of  the  lobe.    Its  width  is  about  12  mm.    The  beveled  surface  on  the  upper 


442. 


Figs.  442  and  443. — Echmatemys  naomi.     Carapace  and  plastron  of  type.     Xi- 
442.  Carapace.  443.  Plastron. 

side  of  this  lobe,  at  the  hyoxiphiplastral  suture,  is  28  mm.  wide.  The  bones  here  have  a  thick- 
ness of  13  mm. 

The  anterior  buttresses  appear  to  arise  but  a  short  distance  within  the  free  border  of  the 
base  of  the  anterior  lobe.  The  posterior  buttresses  reach  inward  from  the  border  of  the  hinder 
lobe  half-way  to  the  midline. 

The  gulars  are  47  mm.  long;  the  humerals,  31  mm.;  the  pectorals,  60  mm.;  the  abdomi- 
nals, 86  mm.;  the  femorals,  53  mm.;  the  anals,  38  mm.  The  humero-pectoral  sulcus  cuts 
across  the  hinder  end  of  the  entoplastron.  The  median  longitudinal  sulcus  runs  a  very  irregular 
course. 

The  axillary  scute  is  large  and  its  hinder  end  joins  the  fifth  marginal  for  a  distance  of  13 
mm.  The  inguinal  scute  is  also  large,  its  outer  boundary  being  38  mm.  long,  and  lacking  12 
mm.  of  reaching  the  sixth  marginal. 

From  all  other  described  species  this  differs  in  the  depth  of  the  channels  in  which  run  most 
of  the  carapacial  sulci.  From  E.  stevensoniana  it  differs  also  in  having  broader  neurals  and  in 
its  broader,  urn-shaped,  vertebral  scutes.    These  scutes  likewise  distinguish  it  from  E.  shaugh- 


EMYDIDjE. 


337 


Fig.  444. — Echmatemys  naomi.    Upper  sur- 
face of  epiplastral  lip  of  type.     X  i- 


nessiana.  Furthermore,  the  free  borders  of  the  nuchal  and  first  pair  of  peripherals  are  acute, 
while  those  of  £.  shaughnessiana  are  rounded.  In  the  type  of  £.  shaughnessiana  the  humero- 
pectoral  sulcus  passes  behind  the  entoplastron;  in  E.  naomi,  across  it. 

In  E.  septaria  the  epiplastral  lip  is  more  contracted,  the  epiplastrals  are  very  thick  at  the 
sides  of  the  lip,  and  the  anterior  lobe  expands  in  front  of  the  base. 

In  E.  ocyrrhoe  the  vertebral  scutes  are  narrower,  the  anterior  marginal  scutes  extend  up 
farther  on  the  peripherals,  the  costal  plates  have  their  opposite  ends  alternately  wide  and 

narrow,  and  the  horn-covered  surface  of  the  upper 
side  of  the  posterior  lobe  is  relatively  much  nar- 
rower. E.  arethusa  has  narrow  vertebral  scutes 
and  a  contracted  epiplastral  lip. 

E.  agle  resembles  E.  naomi  in  respect  to  the 
neural  bones  and  the  form  of  the  vertebral  scutes. 
The  sulci  of  the  carapace  are  not  in  deep  grooves. 
.The  lateral  peripherals  of  E.  naomi  rise  much 
higher  above  the  margin  of  the  carapace  than 
those  of  jE.  (sgle,  the  fifth  of  the  former  rising  46 
mm.,  in  E.  legle  only  34  mm.  On  this  periph- 
eral of  E.  naomi  the  costo-marginal  sulcus  runs 
15  mm.  below  the  upper  border  of  the  bone;  in  E. 
tegle  only  9  mm.  below.  The  axillary  scutes  of 
E.  naomi  are  more  strongly  developt  than  in  E.  cegle,  reaching  backward  and  widely  joining 
the  fifth  marginals;  while  in  E.  cegle  they  lack  much  of  reaching  the  fifth  marginals.  On  the 
other  hand,  the  inguinal  scutes  of  E.  regie  extend  forward  to  the  sixth  marginals,  while 
those  of  E.  naomi  do  not  reach  the  marginals  just  named.  The  epiplastral  lip  is  quite  differ- 
ent in  the  two  species,  and  the  anterior  plastral  lobe  of  E.  isgle  is  relatively  wider.  The 
neurals  of  E.  naomi  are  considerably  broader  than  those  of  E.  cegle. 
Dedicated  to  one  of  the  world's  noble  women  (Ruth  i-iv). 

Echmatemys  pusilla  sp.  nov. 

Figs.  445,  446. 

Emys  wyomingensis,  Leidy,  Contrib.  Ext.  Vert.  Fauna  West.  Terrs.,  1 873,  p.  148,  No.  13. 

This  name  is  bestowed  on  a  small  turtle  which  was  obtained  by  the  writer  in  1903  at 
Grizzly  Buttes,  Wyoming.  The  number  of  the  specimen  in  the  American  Museum  is  5992. 
The  level  is  that  known  as  B.  The  type  specimen  afl^ords  the  greater  part  of  both  carapace 
and  plastron.  The  shell  gives  evidences  of  having  been  immature.  The  total  length  of  the 
carapace  in  a  straight  line  appears  to  have  been  close  to  125  mm.  The  upper  shell  (fig.  446) 
was  apparently  quite  convex. 

The  nuchal  bone  has  a  length  of  24  mm.;  a  width  of  19  mm.  in  front  and  an  extreme  width 

of  28  mm.  The  free  border  is  acute. 
The  greatest  thickness  is  4  mm.;  the 
border  for  articulation  with  the  first 
peripheral  is  slightly  less  than  this.  The 
neurals  are  broad.  Their  dimensions 
are  shown  in  the  table;  also  those  of 
the  vertebral  scutes. 

The  second  neural  is  octagonal. 
The  next  two  are  hexagonal,  with  the 
postero-lateral  angles  truncated.  From 
the  forms  of  the  contiguous  costals  it 
appears  that  the  fifth  neural  had  the  same  form  as  the  fourth,  that  the  sixth  was  four-sided, 
the  seventh  and  the  eighth  hexagonal,  with  the  antero-lateral  angles  truncated. 

All  the  costals  are  represented  in  whole  or  part.     They  are  thin,  about  2  mm.  distally, 
thickening   proximally  to  about  3.5   mm.     On   the  visceral   surface   of  those    of   the    first 
pair  the  axillary  buttresses  ascend  a  considerable  distance  above  the  lower  borders.    At  the 
22 


Dimensions  of  neurals. 

Dimensions  of  vertebral  scutes. 

1 

Width 

Greatest 

No. 

Length. 

- 
■4 

Width. 
II 

No. 

Length 

15 

in  front. 
30 

width.    1 

30 

, 

I 

2 

II 

'i 

1 

26 

'7-5 

30 

3 

12.5 

'3 

3 

^5 

22 

30 

4 

'" 

H 

4 

25  ± 

22  ± 

H±i 

5 

>5± 

33^ 


FOSSIL    TURTI.KS    OK    NORTH    AMKRICA. 


thickened  junction  of  the  fitth  and  sixth  costals  is  an  excavation  for  the  inguinal  buttress. 
This  ascended  about  one-third  the  distance  from  the  lower  border  of  the  costal  to  the  neural 
border. 

The  first,  second,  and  third  peripherals  have  acute  free  borders  and  remains  of  the  bridge 
peripherals  show  that  a  sharp  carina  from  the  third  peripheral  continued  backward  to  the 
hinder  peripherals.  The  costo-marginal  sulci  run  just  below  the  costo-peripheral  sutures. 
The  second  peripheral  has  a  height  of  15  mm.;  the  third,  of  12  mm.;  the  eighth  and  ninth,  of 
15  mm.  The  eighth,  ninth,  and  tenth  are  only  slightly  concave  above.  In  fig.  446  the  last- 
mentioned  peripherals  are  placed  too  near  the  midline.  Most  of  the  vertebral  scutes  are 
broader  than  long. 

The  plastron  (fig.  446)  lacks  the  hinder  extremity.  Its  total  length  was  not  far  from  no 
mm.  The  anterior  lobe  is  38  mm.  long,  58  mm.  wide.  The  epiplastral  lip  is  truncated,  25  mm. 
wide,  and  furnisht  with  a  blunt  tooth  on  each  side.  On  the  upper  side  the  lip  is  thickened 
backward  tor  a  distance  of  16  mm.,  where  there  is  a  sudden  offset.    The  thickness  of  the  lip 


+45- 


Figs.  445  and  446. — Echmatemys  piisiUa.     Plastron  and  carapace  of  type.     X  S- 
445.   Plastron.  446.  Carapace. 

is  about  9  mm.  from  one  side  to  the  other.  The  entoplastron  is  elongated  and  pointed  in  front. 
Its  length  is  26  mm.,  its  width  8  mm.  The  hinder  lobe  of  the  plastron  has  a  width  of  61  mm. 
at  the  base.  Its  free  borders  are  acute.  The  horn-covered  surface  on  the  upper  side  is  1 1  mm. 
wide  and  shows  distinct  impressions  of  the  growth  of  the  scutes.  The  thickness  at  the  hypo- 
xiphiplastral  suture  is  6  mm.  The  inguinal  buttress  extends  inward  from  the  free  border  ot 
the  lobe  little  more  than  one-third  the  distance  to  the  midline. 

The  gular  scutes  overlap  somewhat  the  entoplastron,  as  do  likewise  the  pectorals.  The 
latter  scutes  reach  backward  to  the  hyohypoplastral  suture,  a  condition  not  known  in  other 
species  of  the  genus. 

In  his  monograph  of  1873,  as  cited  at  the  head  of  this  article.  Dr.  Leidy  described, 
as  the  \'oung  ot  his  Emys  wyomingetisis,  a  small  turtle  which  had  been  sent  to  him  from 
Fort  Bridger,  Wyoming,  by  Dr.  Carter.  This  specimen  is  now  in  the  collection  of  the  Phil- 
adelphia Academy. 

The  specimen  agrees  in  all  essential  respects  with  the  type  of  E.  pusilla.  It  furnishes  a 
large  part  of  both  carapace  and  plastron.  The  nuchal  bone  and  all  the  neurals  are  present, 
except  the  fifth.  There  are  2  suprapygals.  Both  first  costals  are  preserved  and  wholes  or 
parts  of  all  those  of  the  left  side.  The  first  right  peripheral  is  in  its  place.  All  the  peripherals 
of  the  left  side  are  present,  except  the  fourth  and  sixth.    The  pygal  is  missing.    Of  the  plastron 


EMYDID^. 


339 


Vertebral. 

Length. 

Width 
in  front. 

Greatest 

width. 

I 

i4 

^5 

»5 

1 

14 

i6 

i6 

i 

Z4± 

i8 

26 

4 

22  ± 

26 

5 

'4 

all  was  secured,  except  the  right  hyoplastron,  a  small  part  of  the  right  hypoplastron,  and  the 
whole  xiphiplastron. 

The  length  of  the  carapace  was  not  far  from  I  lo  mm.  There  is  a  sharp  keel  on  the  nuchal. 
This  is  carried  back  on  the  neurals,  but  is  obtuse  until  the  seventh  is  reacht.  On  this,  but 
especially  on  the  eighth  and  on  the  suprapygals,  it  is  sharp.  The  neurals  are  broad,  as  in  the 
type.  The  third,  not  the  second,  is  octagonal.  The  seventh  is  6  mm.  long  and  I2  mm.  wide; 
the  eighth,  6.5  mm.  long  and  1 1  mm.  wide,  and  is  crost  by  the  sulcus  between  the  fourth  and 
the  fifth  vertebral  scutes.  The  first  suprapygal  is  8  mm.  long  on  the  midline,  6  mm.  wide  in 
front  and  10  mm.  behind;  and  is  deeply  excavated  behind  for  the  second  suprapygal.  This 
is  small,  only  5  mm.  long  and  7  mm.  wide. 

The  plastron  has  a  total  length  of  103  mm.  The  anterior  lobe  is  30  mm.  long  and  54  mm. 
wide  at  the  base.  The  epiplastral  lip  is  24  mm.  wide,  acute-edged,  extends  backward  on  the 
upper  side  13  mm.,  and  is  6  mm.  thick.  The  upper  surface  is  quite  strongly  imprest  by  the 
lines  of  growth  of  the  horny  scutes.  The  axillary  buttresses  extend  but  a  little  distance  within 
the  free  borders  of  the  base  of  the  lobe.  The  entoplastron  is  long  and  narrow,  as  in  the  type, 
being  22  mm.  long  and  18  mm.  wide.     The  bridge  is  36  mm.  wide. 

The  hinder  lobe  is  35  mm.  long  and  55  mm.  wide  at  the  base.  In  the  rear  there  is  a  rather 
deep  notch.    The  free  borders  are  acute.    On  the  upper  side,  at  the  hypoxiphiplastral  suture, 

the  horn-covered  surface  is  10  mm.  wide.  Here  the 
bones  are  5  mm.  thick.  The  inguinal  buttress  extends 
inward  about  one-third  the  distance  from  the  free  bor- 
der of  the  lobe  to  the  midline. 

The  sulci  are  very  distinct.    The  dimensions  of  the 
vertebral  scutes  are  given  in  the  table  herewith. 

The  gulars  barely  reach  the  entoplastron.  The 
humero-pectoral  sulcus  crosses  at  about  the  middle  of 
the  length  of  the  entoplastron.  As  in  the  type,  the  pec- 
toro-abdominal  sulcus  is  carried  back  nearly  to  the  hyohypoplastral  suture.  The  femoro- 
abdominal  sulcus  crosses  the  lobe  in  a  nearly  straight  line.  The  femorals  measure  along  the 
midline,  19  mm.;  the  anals,  13  mm. 

This  species  resembles  in  several  respects  Clemmys  morrista.  It  differs,  however,  in  having 
the  free  borders  of  the  second  and  third  peripherals  acute,  instead  of  obtusely  rounded,  and  in 
having  the  inguinal  buttresses  rise  well  within  the  free  border  of  the  plastron.  The  epiplastral 
lip  resembles  in  form  closely  that  of  C.  morrisite,  and  it  is  markt  on  its  upper  surface  with 
similar  ridges,  though  not  so  strongly  developt. 

Echmatemys?  latilabiata  (Cope). 

Emys  laiilabiatus,  CoPE,  Proc.  Amer.  Philos.  Soc,  xil,  1872,  p.  471;  Sixth  Ann.  Report  U.  S.  Geo!. 

Surv.,  1872  (1873),  pp.  625,  626;  Vert.  Tert.  Form.  West,  1884,  p.  138. 
Emys  latilabiata,  Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  448. 

The  present  species  has  never  been  figured.  In  his  work  on  the  Vertebrata  of  the  Tertiary 
Formations  of  the  West,  cited  above.  Professor  Cope  stated  that  the  type  had  been  mislaid. 
So  far  as  the  present  writer  knows,  it  has  not  been  recovered  up  to  the  present  time.  It  is 
possible  that  at  some  time  another  specimen  may  be  discovered  that  can  be  identified  by 
means  of  the  description.  The  striking  characters  of  the  species,  so  far  as  indicated  by  Cope's 
description,  are  the  relatively  great  breadth  of  the  shell  and  the  wide  epiplastral  lip.  The 
following  is  Cope's  latest  description: 

Represented  by  a  perfect  specimen  of  a  tortoise  of  a  broadly  oval  form,  and  somewhat  terrestrial 
habit.  Its  prominent  characters  are  to  be  seen  in  the  plastron,  of  which  the  posterior  lobe  is  deeply 
bifurcate.  The  anterior  lobe  is  peculiar  in  the  unusual  width  of  the  lip-like  projection  of  the  clavic- 
ular ("episternal")  bone,  which  is  twice  as  wide  as  in  E.  wyommgensis,  and  not  prominent.  Bones 
all  smooth;   margins  of  lobes  of  plastron  thickened. 

There  are  three  scars,  perhaps,  of  mu.scular  insertions  near  the  posterior  margin  of  the  plastron, 
an  oval  one  opposite  to  each  lobe,  and  a  round  one  opposite  to  the  notch. 

As  compared  with  E.  septaria  this  species  has  no  such  septa  nor  sculpture;  the  emargination  of 
the  plastron  is  more  open,  and  the  lip  much  shorter  and  wider. 


340  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

Measurements. 

Meter. 

Length  of  carapace o-^55 

Width  of  carapace 250 

Width  of  lip  of  plastron 060 

Depth  of  posterior  notch  .020 

1  he  temporary  misplacement  of  the  typical  specimen  of  this  species  prevents  my  givmg  other 
than  my  original  description. 

From  near  Black's  Fork  of  Green  River. 

This  species  was  obtained  in  horizon  B  of  the  Bridger  Eocene. 

Ecbmatemys  callopyge  sp.  nov. 
Plate  52,  figs.  I,  2;    text-figs.  447,  448. 

As  type  of  this  species  the  American  Museum  of  Natural  History  possesses  a  large  and 
complete  shell,  No.  2087.  It  was  collected  in  the  year  1895,  in  the  middle  Uinta  deposits  near 
White  River,  Utah. 

The  shell  is  slightly  crusht  over  toward  the  left  side,  a  part  of  the  right  side  is  broken  in, 
and  a  portion  of  the  left  margin  is  somewhat  damaged;    but  there  is  nothing  to  prevent  the 


447- 


Figs.  447  and  448. — Echmatemys  callopyge.     Carapace  and  plastron  of  type.     Xii. 
447.  Carapace.  44^.  Plastron. 

determination  of  all  the  external  characters  that  the  shell  offers.  It  would  require  the  inflicting 
of  much  injury  on  the  specimen  to  reach  and  examine  the  axillary  and  inguinal  buttresses. 
Hence  their  condition  is  not  certainly  known. 

The  form  of  the  carapace  (plate  52,  fig.  i;  text-fig.  447)  is  elongated  oval,  rounded  in 
front  and  pointed  behind,  with  the  median  portion  high  and  vaulted.  The  plastron  is  broad 
and  it  left  but  little  space  for  the  exit  of  the  limbs. 

The  length  of  the  carapace,  in  a  straight  line,  is  438  mm.;  its  width  is  270  mm.;  its  height 
is  now  153  mm.  The  latter  dimension  was  doubtless  somewhat  greater  during  the  life  of  the 
animal.  There  is  a  rather  broad  elevation  running  along  the  midline  of  the  first  vertebral 
scute  and  another  on  the  last  vertebral;  elsewhere  there  is  no  indication  of  any  carina.  The 
margin  of  the  carapace  behind  the  inguinal  notches  is  thin  and  comes  to  a  sharp  edge.    This 


EMYDID^. 


341 


region  is  not  at  all  serrated;    but  it  is  somewhat  flared  upward.     The  surface  of  the  shell  is 
smooth.    The  sulci  are  narrow  but  rather  deeply  imprest. 

The  neural  plates  are  in  general  hexagonal,  with  the  broad  end  forward.  The  second  to 
the  fifth,  inclusive,  have  the  anterior  end  more  or  less  concave.  Most  of  the  neurals  are  longer 
than  broad,  but  the  posterior  are  broader  than  long.  The  table  herewith  gives  the  dimensions 
of  the  neurals. 


Dimensions  of  ueurals. 


Dimensions  of  vertebrals. 


Width     Greatest  I 


No.    Length.;  Width.       No.      Length.  .     ,  . ,  , ' 

*       i  "in  front,     width 


5» 

33 

I 

75 

43 

39 

2 

89 

58 

43 

3 

88 

4' 

37 

♦ 

96 

4' 

44 

74 

30 

40 

29 

45 

28 

34 

t 

5i 
47 
5^ 
5') 
44 


^2 

Si 

S7 

IOO± 


Dimensions  of  marginals. 


^  Height    Greatest 

in  front,    height. 


18 
26 


45 


Length 
at  free 
border. 


32  40 

29  47 

27  4^ 

47  45 


The  nuchal  is  68  mm.  long,  50  mm.  wide  at  the  free  border,  and  has  a  maximum  width  of 
80  mm.  The  first  suprapygal  is  33  mm.  long  and  29  mm.  wide;  the  second  42  mm.  long  and 
90  mm.  wide.  The  pygal  has  a  length  of  30  mm.  and  a  width  of  40  mm.  The  free  border  of 
the  nuchal  and  the  first  peripherals  is  acute. 

The  peripherals  are  high.  In  front,  they  extend  upward  above  the  margin  of  the  shell 
about  46  mm.;  laterally  about  62  mm.;  at  the  inguinal  notch,  about  70  mm.;  the  most 
posterior,  about  28  mm. 

All  the  vertebral  scutes  are  longer  than  broad,  except  the  fifth.  The  first  is  unusually 
narrow.  The  sides  of  the  median  three  are  bracket-shaped.  The  dimensions  are  given  in  the 
middle  table  above. 

Besides  the  nuchal  scute,  there  are  on  each  side  the  usual  12  marginals.  These  do  not  rise 
to  the  upper  borders  of  the  peripheral  bones.  The  nuchal  scute  is  very  narrow,  only  14  mm.; 
its  length  is  16  mm.    The  dimensions  of  the  marginals  are  shown  in  the  table  above. 

The  plastron  (plate  52,  fig.  2;  text-fig.  448)  has  a  total  length  of  410  mm.  The  anterior 
lobe  is  1 16  mm.  long  and  174  mm.  wide.  The  posterior  lobe  is  135  mm.  in  length  and  198  mm. 
in  width.  The  bridge  is  155  mm.  wide.  The  anterior  lobe  is  slighth'  contracted  just  in  front 
of  the  axillary  notch;  then  expands  a  little  to  the  ends  of  the  epiplastra;  then  curves  slowly 
to  the  truncated  lip.  The  latter  is  unusually  narrow,  having  a  width  of  only  38  mm.,  being  less 
than  one-fourth  of  the  width  of  the  anterior  lobe.  It  is  markt  outwardh'  on  each  side  by  a  stout 
tooth,  mesiad  of  which  there  is  a  notch.  In  the  latter  are  three  smaller  teeth.  On  the  upper 
side  of  the  bone  there  is,  along  the  midline,  a  prominent  ridge,  48  mm.  long  and  bounded  on 
each  side  by  a  valley,  the  latter  opening  in  front  at  the  notch  of  the  lip.  At  the  hinder  end  of 
the  ridge  is  a  transverse  ridge,  which  passes  outward  and  backward.  About  the  middle  of  its 
length  the  epiplastron  has  a  thickness  of  15  mm. 

The  length  of  the  entoplastron  is  72  mm.;  the  width,  74  mm.  The  hyoplastra  are  94  mm. 
along  the  midline,  and  each  extends  laterally  about  104  mm.  The  hypoplastra  join  along  the 
midline  for  a  distance  of  100  mm.  The  xiphiplastrals  meet  along  the  midline  85  mm.  The 
notch  between  their  hinder  ends  is  15  mm.  deep;    the  distance  between  the  tips  is  34  mm. 

There  are  the  usual  scutes  on  the  plastron.  The  gulars,  taken  together,  are  64  mm.  wide 
in  front.  They  extend  backward  well  on  the  entoplastron,  their  median  length  being  72  mm. 
The  humerals  meet  along  the  midline  for  a  distance  of  35  mm.  The  pectorals  encroach  on  the 
entoplastron.  The  suture  between  them  is  74  mm.  long.  The  abdominals  extend  along  the 
midline  for  1 10  mm.  The  femorals  are  only  38  mm.  fore  and  aft  at  the  midline;  but  93  mm. 
at  their  outer  ends.  The  anals  occupy  66  mm.  of  the  midline.  On  account  of  some  crushing 
the  axillary  scute  can  not  be  made  out.  It  is  certain,  however,  that  it  failed  by  at  least  25  mm. 
to  reach  backward  to  the  fifth  marginal.  The  inguinal  scute  lackt  about  27  mm.  of  extend- 
ing forward  to  the  sixth  marginal. 


342 


rOSSll.    TURTI.KS    OF    NORTH    AMERICA. 


The  very  narrow  first  vertebral  scute  distinguishes  this  species  from  all  others,  especially 
from  E.  uintensis,  which  also  comes  trom  the  Uinta  formation.  From  many  species  it  is  dis- 
tinguisht  by  the  rather  broad  vertebrals  succeeding  the  first.  The  narrow  epiplastral  lip  and 
the  longitudinal  ridge  on  the  upper  side  of  the  symphysis  are  peculiarities.  The  femoral 
scutes  are  unusually  narrow  at  the  midline.  The  species  resembles  somewhat  E.  septaria 
(Cope),  but  the  vertebral  scutes  of  the  two  are  different,  and  the  epiplastron  of  E.  callopyge 
appears  not  to  have  been  so  greatly  thickened  as  in  E.  septaria. 


Echmatemys  uintensis   sp.  nov. 
Plate  53,  figs,  i,  z. 

In  the  paleontological  collection  at  Princeton  University  there  is  a  fine,  large  shell  of  a 
species  of  Echmatemys  which  was  collected  in  1895,  by  Mr.  J.  B.  Hatcher,  in  the  middle 
Uinta  formation,  on  White  River,  Utah.  It  bears  the  catalog  number  11 198.  This  shell  is 
practically  complete  and  but  little  crusht.  The  total  length,  in  a  straight  line,  is  460  mm.; 
the  width,  295  mm.;  the  height  above  the  bottom  of  the  plastron,  160  mm.  In  outline  the 
carapace  is  somewhat  concave  in  front,  rounded  behind.  The  hinder  peripherals  flare  slightly 
upward. 

On  the  nuchal  bone  and  the  anterior  neurals  there  is  a  slight  ridge;  and  this  reappears  and 
is  more  prominent  on  the  hinder  third  of  the  shell. 

The  nuchal  bone  is  67  mm.  long  and  107  mm.  wide.  It  is  excavated  behind  for  the  first 
neural.    The  neurals  are  relatively  broad,  the  second,  third,  and  fourth  hexagonal;   the  fifth 

octagonal,  joining  the  fourth,  fifth  and 
sixth  costals;  the  sixth  and  seventh 
broadly  hexagonal;  the  eighth  nearly 
quadrate.  The  table  shows  the  dimen- 
sions of  the  neurals. 

The  first  suprapygal  is  37  mm.  long, 
21  mm.  wide  in  front,  and  42  mm.  wide 
posteriorly.  The  second  is  47  mm.  long 
and  1 15  mm.  wide. 

The  first  peripheral  has  the  free  edges 
moderately  acute,  but  toward  the  axil- 
lary notch  the  others  become  obtuse. 
All  these  rise  above  the  free  margin  about 
60  mm.  The  eighth  peripheral  is  67  mm.  high.  The  pygal  is  42  mm.  wide  and  38  mm.  high. 
The  vertebral  scutes  are  longer  than  wide  with  the  sides  nearly  straight,  except  where  the 
sulci  dividing  the  costal  scutes  are  given  ofl^.  The  dimensions  of  these  scutes  are  given  above. 
The  anterior  suprapygal  is  37  mm.  long,  21  mm.  wide  in  front,  and  41  mm.  behind.  The 
second  suprapygal  is  49  mm.  long,  105  mm.  wide  across  the  middle,  33  mm.  where  it  joins  the 
pygal.     The  hinder  boundary  of  the  fifth  vertebral  scute  lies  on  the  second  suprapygal. 

The  axillary  and  inguinal  buttresses  rise  high  within  the  carapace,  but  the  details  are  not 
known.  They  extend  at  their  bases  but  a  short  distance  inward  beyond  the  free  borders  of 
the  plastron. 

The  anterior  lobe  of  the  plastron  is  120  mm.  long  and  200  mm.  wide  at  the  base.  From 
the  axillae  the  width  decreases  slowly  to  just  beyond  the  hyoepiplastral  suture,  then  more 
rapidly  by  a  sigmoid  curve  to  the  lip.  The  latter  is  65  mm.  wide  and  truncated.  It  projects 
little  beyond  the  ends  of  the  gulo-humeral  sulci.  As  seen  from  below,  it  is  convex  from  side  to 
side;  as  seen  from  above,  concave.  The  thickened  portion  of  the  lip  continues  backward 
30  mm.;  and  behind  it  the  thickness  is  not  greatly  reduced.  The  free  border  of  this  lobe  is 
acute.  On  the  upper  surface  of  the  bone  the  horn-covered  surface  is  23  mm.  wide. 
The  entoplastron  is  diamond-shaped,  70  mm.  long  and  95  mm.  wide. 

The  hinder  lobe  is  150  mm.  long  and  200  mm.  wide  at  the  base.  The  notch  in  the  hinder 
end  is  16  mm.  deep  and  55  mm.  wide.  The  border  of  the  lobe  is  acute.  Seen  from  above,  the 
beveled  surface  is  37  mm.  wide  at  the  hypoxiphiplastral  suture;  at  the  femoro-anal  sulcus 
only  15  mm.    At  the  inner  border  of  the  bevel  the  thickness  is  20  mm. 


Dimensions  of  neurals. 

Dimensions  of  vertebral  scutes. 

No.        Length. 

Width. 

No. 

Length. 

Width     Greatest 

in  front. 1    width. 

1 

60 

, 

70 

112 

IIZ 

2 

43 

z 

115 

80 

102 

3 

5° 

3 

<)i 

80 

81 

4 

5° 

4 

78 

75 

94 

34 

5 

86 

43 

132 

30 

10 

50 

^5 

30 

EMYDin^.  343 

The  epiplastrals  occupy  44  mm.  of  the  midline;  the  hyoplastrals,  125  mm.;  the  hypoplas- 
trals,  120  mm.;  the  xiphiplastrals,  8  mm.  At  the  junction  of  the  hyoplastrals  and  hypoplas- 
trals,  at  the  midline,  the  thickness  is  17  mm. 

Measured  on  the  midline  the  gulars  are  57  mm.  long;  the  humerals,  40  mm.;  the  pectorals, 
73  mm.;  the  ahdominals,  1 15  mm.;  the  femorals,  70  mm.;  the  anals,  52  mm.;  both  the  gulars 
and  the  pectorals  encroach  on  the  entoplastron. 

In  many  respects  this  species  resembles  E.  wyomtngensis  of  the  Bridger  beds.  It  is,  how- 
ever, improbable  that  the  latter  species  continued  on  into  the  Uinta  epoch.  Furthermore, 
differences  are  presented,  notably  in  the  greater  width  of  most  of  the  vertebral  scutes. 

Genus   PAL.1EOTHECA   Cope. 

Species  small,  with  thick  and  solid  bones.  A  dorsal  keel  present.  Scutal  sulci  deeply 
imprest.  The  epiplastral  lip  projecting  and  the  inguinal  buttress  probably  ascending  above  the 
borders  of  the  fifth  and  sixth  costals. 

Type:     Palteotheca  polycypha  Cope. 

This  hardly  definable  genus  was  establisht  by  Cope  to  contain  his  species  P.  polycypha 
and  P.  ti-nrstris.  These  he  afterwards  referred  to  Emys.  As  there  is  neither  evidence  nor 
probability  that  the  species  belong  to  Ernys  as  now  understood,  the  species  must  be  removed 
to  some  other  genus.  It  is  possible  that  they  belong  in  Echmatemys,  but  of  this  there  is  little 
evidence.  They  are  very  imperfectly  known  species;  and  as  the  genus  Palteotheca  has  been 
already  establisht  for  them,  it  seems  that  no  confusion  or  inconvenience  will  be  produced  in 
retaining  them  there  until  more  is  ascertained  regarding  their  structure  and  relationships. 

Cope  suspected  that  these  small  turtles  might  be  the  young  of  species  already  described 
from  adult  remains,  but  he  concluded  that  they  had  too  many  features  of  maturity  to  be  merely 
young  animals.  Cope  thought  also  that  they  showed  relationships  with  the  modern  genera 
Terrapene  (Cistudo)  and  Testudo;  but  there  appears  to  be  little  probability  of  this. 

.Unfortunately  the  types  of  both  the  species  here  described  are  extremely  fragmentary. 

PalsBOtheca  polycypha  Cope. 

Palteotheca  polycypha,  CoPE,  Palaeont.  Bull.,  No.  I,  1872,  p.  46^;    Proc.  .Anicr.   rhilos.  Soc,  xil,  187^, 

p.  463. 
Emys  polycyphus.  Cope,  Sixth  Ann.  Report  U.  S.  Geo!.  Surv.  Terrs.,  1872  (1873),  p.  625,  629. 
Em\'s  polycypha,  Cope,  Vert.  Tert.  Form.  We.st,  1884,  pp.  129,  131,  plate  xviii,  figs.  20-22. 

The  type  of  the  present  species  is  in  the  U.  S.  National  Museum  and  bears  the  catalog 
number  4097.  The  species  was  based  on  very  meager  materials  and  only  a  portion  of  this  was 
figured.  The  remains  were  found  in  the  Bridger  beds,  but  the  exact  locality  and  level  were  not 
communicated. 

The  following  is  Cope's  description: 

This  species  of  tortoise  is  indicated  by  vertebral,  costal,  and  marginal  bones  of  very  small  indi- 
viduals. These  bones  are,  however,  not  only  thoroughly  ossified,  but  are  very  stout,  indicating  the  adult 
age  of  the  animal.  The  deeply  impressed  scutal  sutures,  and  heavy  proportions,  as  well  as  the  elevated 
carina  of  the  carapace,  indicate  affinity  with  Cistudo,  or,  perhaps,  Testudo.  As  a  generic  character, 
it  may  be  noted  that  the  vertebral  bones  are  subquadrate,  and  support  the  neural  canal  without 
intervening  lamina. 

The  carina  of  the  carapace  is  abruptly  interrupted  at  intervals;  sometimes  with,  sometimes  with- 
out, a  pair  of  pits,  one  on  each  side.  The  marginal  bones  are  well  secured  and  the  .scutal  sutures  are 
deeply  impressed  on  them. 

Meaiurementi. 

Mettr. 

Length  of  vertebral  bone 0.009 

Width  of  vertebral  bone 0085 

Length  of  marginal  bone 01 

This  is  the  least  of  the  tortoises  of  the  Bridger  formation. 

The  measurements  given  above  of  the  neural  (vertebral  bone)  apply  to  neither  of  those 
figured  by  Cope.    The  original  of  his  fig.  20  represents  a  neural  8  mm.  long  and  8  mm.  wide. 


344  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

The  figure  itself  is  incorrect.  His  fig.  21  is  that  of  a  bone  7  mm.  long  and  8  mm.  wide.  The 
bones  figured  indicate  a  turtle  which  had  a  carapace  about  100  mm.  long.  The  originals  of 
Cope's  figs.  20,  21,  and  22  are  in  the  U.  S.  National  Museum.  We  are  not  informed  by  that 
writer  whether  or  not  these  bones  belonged  to  a  single  individual.  If  they  do,  his  fig.  21  repre- 
sents the  seventh  neural  and  his  figure  20  the  eighth.  Cope's  fig.  22  represents  a  peripheral. 
In  its  upper  border  there  is  a  pit  for  the  end  of  a  rib.    The  fore-and-aft  extent  of  the  bone  is 

9  mm.     Its  free  border  is  broken  away,  but  the  height  of  the  bone  was  somewhat  more  than 

10  mm.  It  is  considerably  recurved.  Its  thickness  is  between  3  mm.  and  4  mm.  The  sulci 
crossing  it  are  broad  and  rather  deeply  imprest. 

Palseotheca  terrestris  Cope. 

Palceotheca  terrestris,  Covt.,  Palaeont.  Bull.  No.  I,  1872,  p.  464;  Proc.  Amer.  Philos.  Soc,  xil,  1873,  p.  464. 
Emys  terrestris.  Cope,  Sixth  Ann.  Report  U.  S.  Gaol.  Surv.  Terrs.,  1872  (1873),  pp.  625,629;  Vert.Tert. 

Form.  West,  1884,  pp.  129,  130,  131,  plate  xviii,  figs.  23-25. — Hay,  Bibliog.  and  Cat.  Foss.  Vert. 

N.  A.,  1902,  p.  448. 

Of  Cope's  specimens  of  this  species,  three  in  number,  those  parts  represented  by  his 
figs.  23,  24,  and  25  of  the  plate  cited  are  in  the  U.  S.  National  Museum  and  have  the  number 
2107.  All  his  materials  were  found  in  Bridger  strata,  but  the  exact  locality  and  level  are 
nowhere  mentioned.  They  were  undoubtedly  secured  somewhere  in  the  region  about  Fort 
Bridger,  Wyoming. 

Of  his  type  specimen  Cope  figured  i  neural,  i  costal,  and  the  right  epiplastron.  In  his 
description  he  probably  intended  to  give  the  measurements  of  the  neural  figured.  At  any  rate, 
there  is  some  error,  for  it  is  not  probable  that  any  neural  was  twice  as  wide  as  long.  The  neural 
figured  is  9  mm.  long  and  13  mm.  wide.  The  width  of  the  costal  is  given  as  1 1  mm.,  whereas 
the  width  of  his  figure  25  is  only  a  little  more  than  10  mm. 

This  species  is  stated  by  Cope  to  differ  from  P.  polycypha  in  having  bones  at  once  larger 
and  thinner;  and  this  is  confirmed  by  a  comparison  of  the  neurals  of  the  two  species,  as  they 
are  figured.  As  in  the  case  of  P.  polycypha,  there  was  a  dorsal  carina,  and  this  was  interrupted 
by  the  deeply  imprest  scutal  sulci  which  crost  it. 

The  epiplastron  is  19.5  mm.  long  and  18  mm.  wide.  The  lip  projected  abruptly  from  the 
general  outline  about  3  mm.  and  was  truncated.  The  anterior  edge  was  acute.  At  its  base  the 
lip  was  21  mm.  wide  and  nearly  as  wide  in  front,  the  width  of  the  half  of  it  present  being  10  mm. 
On  the  upper  side  of  the  lip  the  bone  was  thickened  backward  for  a  distance  of  about  1 1  mm., 
the  greatest  thickness  being  4.5  mm. 

Cope's  fig.  25^  gives  a  view  of  the  hinder  articular  border  of  a  costal.  This  is  3  mm.  thick 
at  the  proximal  end  of  the  bone,  but  at  the  lower  end  is  5  mm.  This  costal  appears  to  be  the 
fifth  of  the  right  side;  and  with  the  succeeding  one  formed  a  ridge  for  the  inguinal  buttress.  As 
shown  by  Cope's  fig.  25a,  at  the  lower  end  of  the  bone  and  at  its  hinder  border  there  was  the 
half  of  an  excavation  for  this  buttress.  About  the  distal  half  of  the  costal  is  broken  away  and 
the  buttress  therefore  ascended  one-half  the  height  of  the  costal.  The  rib-head  is  hardly  dis- 
cernible. The  proximal  end  of  the  costal  does  not  join  accurately  the  neural  of  Cope's  fig.  23; 
hence  it  is  concluded  that  this  neural  is  the  third.  The  costo-vertebral  sulcus  (Cope's  fig.  25) 
crosses  the  costal  at  a  distance  of  5  mm.  from  the  proximal  end,  from  which  fact  it  is  concluded 
that  the  fourth  vertebral  scute  was  about  28  mm.  wide.  The  turtle  was  undoubtedly  a  small 
one  with  a  thick,  heavy  shell. 

Cope  states  that  the  articulations  of  the  bridge  with  the  costals  were  not  known  to  him. 

No  specimens  belonging  to  this  species  or  to  P.  polycypha  were  secured  by  the  expedition 
from  the  American  Museum  of  Natural  History  into  the  Bridger  beds  in  1903. 

Genus   HYBEMYS  Leidy. 

Insufficiently  known  emydoid  turtles,  the  upper  surface  of  whose  peripherals  was  orna- 
mented by  a  row  of  hemispherical  bosses,  each  of  which  was  crost  by  the  suture  between  the 
two  peripherals  on  which  it  rested. 

Type:   Hybemys  arenaria  Leidy. 


EMYDID^.  345 

Hybemys  arenaria  Leidy. 

Hybemys  arenarius,  Leidy,  Proc.  Acad.  Nat.  Sci.  I'hila.  1871,  p.  103;  Fifth  Ann.  Report  U.  S.  Geol. 
Surv.  Montana,  etc.,  1871,  (1872),  p.  369;  Contrib.  Ext.  Vert.  Fauna  West.  Terrs.,  1873,  p.  174, 
plate  XV,  fig.  9. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  448. 

This  species  was  based  by  Dr.  Leidy  on  a  single  peripheral  and  a  fragment  of  a  costal  of 
an  emydoid  turtle  believed  to  be  about  the  size  of  Chrysemys  picta  or  Clemmys  guttata.  These 
bones  were  secured  on  Little  Sandy  Creek,  Wyoming.  The  level  is  that  known  as  horizon  A 
of  the  Bridget  Eocene.  The  specimen  belongs  to  the  Academy  of  Natural  Sciences,  Phila- 
delphia. 

The  bones  are  described  as  being  unusually  thick  in  proportion  to  the  width.  The  sulci 
are  strongly  markt.  The  rib-heads  are  stout.  The  outer  portion  of  the  upper  surface  of  the 
peripheral  is  strongly  defined  by  the  groove  of  the  costo-marginal  sulcus.  At  the  anterior  and 
the  posterior  ends  of  the  peripheral  there  is  seen  a  semicircular  boss.  It  is  inferred  that  the 
other  peripherals  had  at  each  end  a  similar  semicircular  boss,  so  that  around  the  carapace, 
on  the  peripherals,  there  was  a  row  of  hemispherical  elevations,  each  of  which  was  crost  by  the 
suture  between  the  two  peripherals  on  which  it  rested. 

Genus  CHRYSEMYS  Gray. 

Shell  smooth,  deprest,  without  traces  of  dorsal  keel.  Carapace  not  serrated  behind; 
often  dentated  in  front.  Plastron  with  broad  anterior  and  posterior  lobes.  The  anterior  lobe 
with  a  distinct  lip  which  is  often  dentated.  Posterior  lobe  truncated  behind,  scarcely  notcht. 
Inguinal  buttresses  articulating  with  the  fifth  costals.  Alveolar  surfaces  of  the  upper  jaw 
narrow  in  front,  increasing  in  width  backward,  never  very  broad,  and  with  a  feeble  longi- 
tudinal ridge.  Choanae  on  line  joining  the  fronts  of  orbits.  Alveolar  surface  of  lower  jaw  with 
a  longitudinal  groove  bounded  inwardly  by  a  sharp  ridge.    Symphysis  of  lower  jaw  very  short. 

The  type  of  this  genus  is  Chrysemys  picta,  the  painted  turtle  of  the  Atlantic  states  of  the 
Union.  From  the  Alleghenies  to  the  Mississippi  River  the  genus  is  represented  by  C.  ctnerea. 
West  of  the  Mississippi  river  we  find  C.  belli;  while  in  the  lower  region  of  that  great  stream  is 
found  another  species  or  race,  C.  dorsalis. 

To  the  writer  it  appears  that  these  species  form  a  natural  group  worthy  of  generic  rank, 
and  that  C.  timtda  is  an  extinct  member  of  that  group. 

Chrysemys  timida  sp.  nov. 
Plate  46,  fig.  2;    text-fig.  449. 

Chrysemys  timida  is  founded  on  a  shell  which  belongs  to  the  E.  &  M.  Museum  of  Princeton 
University,  and  has  the  catalog  number  10853.  ^^  ^^^  collected  by  the  University  expedition, 
in  the  Equus  beds  of  Sheridan  County,  Nebraska,  not  far  from  the  Niobrara  River.  Doubtless, 
as  it  lay  in  the  matrix  it  was  complete;  but  from  the  vicissitudes  of  collecting,  transporting 
and  preparing,  it  has  suffered  somewhat.  The  matrix  is  sand  that  scarcely  coheres  and  the 
bone  itself  is  friable.  In  its  present  condition  most  ot  the  peripherals  of  the  left  side  are  gone 
and  considerable  portions  of  those  of  the  right  side.     The  other  parts  of  the  carapace  are  in 

good  condition  and  display  well  the  bone 
sutures  and  the  sulci.  Portions  of  the 
plastron  have  crumbled  away,  but  the 
structure  can  be  pretty  satisfactorily 
determined. 

The  individuals  of  this  species  reacht 
a  considerable  size,  compared  with  those 
now  Hving,  being  about  equal  to  C.  belli. 
The  extreme  length  of  the  carapace 
(plate  46,  fig.  2 ;  text-fig.  449)  was  perhaps 
a  little  more  than  160  mm.;  the  breadth, 
about  120  mm.    The  shell  was  evidently 


Dimensions  of  neuials. 

No. 

Length.     Width. 

No 

I 

16              10 

I 

i 

14             12 

2 

3 
4 
5 
6 

14              "4 
■4       1       "4 

II              12 

3 
4 
5 

7 
8 

10              8 
13               6 

1 

imensions 

of  vertebr< 

!s. 
Greatest 

Width 

I         1 
Length 

1  in  front. 

width. 

30 

1     ■ 
45 

45 

28 

26 

46 

29 

34 

48 

3^ 

3^ 

42 

^7 

20 

42 

1 

346 


FOSSIL    TURTLES    OF    NORTH    AMFRICA. 


considerabl)  deprest,  but  probably  less  so  than  its  present  height,  40  mm.,  indicates.  We 
can  not  determine  to  what  extent,  if  any,  the  hinder  border  of  the  carapace  was  notcht.  The 
hinder  peripherals  are  slightly  recurved.  Their  free  margins  are  acute.  No  carina  is  pres- 
ent, but  on  the  nuchal  and  the  first  neural  there  is  a  perceptible 
elevation.  In  the  region  of  the  hinder  neurals  there  is  a  decided 
longitudinal  depression.  The  surface  is  smooth,  except  that  on 
the  outer  ends  of  the  costals  there  are  longitudinal  ridges  and 
grooves,  due  to  the  growth  of  the  epidermal  scutes. 

The  neural  bones  are  rather  narrow  in  comparison  with  those 
of  C.  ptcta.  Most  ot  them  are  hexagonal,  with  the  broader  end 
forward.  The  dimensions  of  the  neurals  are  shown  in  the  table 
on  page  345. 

The  nuchal  had  a  median  length  of  more  than  30  mm.,  a  mar- 
ginal width  of  about  20  mm.,  and  an  extreme  width  of  35  mm. 
The  suprapygal  plates  are  three  in  number.  The  first  has  a  length 
of  5.5  mm.  and  a  width  of  10  mm.  The  second  is  bifurcate, 
like  the  same  bone  in  Tesiudo,  the  hinder  border  being  deeply 
concave.  The  median  length  is  7  mm.,  the  extreme  width,  21  mm. 
The  third  is  nearly  diamond-shaped,  fitting  in  between  the  second 
suprapygal  and  the  pygal.  It  is  8  mm.  long  and  15  mm.  wide. 
The  pygal  is  22  mm.  wide,  17  mm.  long  and  4.5  mm.  thick. 

The  first  peripheral  is  20  mm.  fore  and  aft  and  the  same 
along  the  free  margin.  The  eleventh  is  18  mm.  high  and  17  mm. 
along  the  free  margin. 

The  plastron  is  somewhat  damaged.  It  is  157  mm.  long. 
The  anterior  lobe  is  43  mm.  long  and  72  mm.  wide  at  the  base. 
The  lip  is  truncated  and  appears  to  have  been  40  mm.  wide. 
The  hinder  lobe  is  55  mm.  long  and  84  mm.  wide  at  the  base.  A  broad  notch  occupied  the 
hinder  end.     The  inguinal  buttress  is  attacht  to  the  fifth  costal  plate. 

The  entoplastron  is  25  mm.  long  and  27  mm.  wide.  The  hypoxiphiplastral  suture  appears 
to  have  run  nearly  straight  across  the  hinder  plastral  lobe. 

The  hyoplastrals  occupy  about  36  mm.  of  the  midline;  the  hypoplastrals,  about  48  mm.; 
the  xiphiplastrals,  about  37  mm. 

The  vertebral  scutes  are  rather  broad  and  are  strongly  bracket-shaped  laterally.  Their 
dimensions  are  given  in  tabular  form  on  the  preceding  page. 

The  inferior  surface  of  the  plastron  is  injured  so  that  few  of  the  sulci  can  be  traced.  The 
abdomino-femoral  passes  between  the  inguinal  notches  with  a  slight  convexity  forward.  The 
femoro-anal  sulcus  is  directed  outward  and  backward.  The  femoral  scutes  are  about  18  mm. 
long  on  the  midline;   the  anals.  about  30  mm. 

Genus  DEIROCHELYS  Agassiz. 

DiflFers  from  Chrysemys  in  having  the  heads  of  the  ribs  long  and  thread-like,  and  the  shell 
sculptured. 

Type:    Deirochelys  reticulata  (Daudin). 

The  following  species  is  referred  provisionally  to  Deirochelys. 


Fig.  449. — Chrysemys  timtda. 
Carapace.   Xi- 


Deirochelys  floridana  sp.  nov. 

Plate  54,  figs.  I,  2;   text-fig.  450. 

The  nuchal  bone  on  which  the  present  species  is  based  is  a  part  of  the  Jarman  collection, 
the  property  of  the  Vanderbilt  University,  Nashville,  Tennessee.  The  collection  was  obtained 
in  Hillsboro  County,  Florida,  and  the  deposits  probably  belong  to  the  Peace  Creek  beds. 
While  the  generic  position  of  the  species  is  not  assured,  the  form  of  the  bone  and  especially  its 
sculpture  so  much  resemble  that  of  Deirochelys  reticulata  that  it  is  referred  to  the  latter  inter- 
esting genus. 


EMYDIDii:. 


347 


The  nuchal  bone  here  described  has  a  median  length  of  70  mm.  The  anterior  border  has 
a  width  of  37  mm.  The  extent  between  the  lateral  angles  is  77  mm.  The  hinder  border 
measures  17  mm.  The  anterior  border  is  acute.  From  this  the  bone  thickens  backward  on 
the  under  side  for  a  distance  of  40  mm.  Here  the  thickness  is  20  mm.  On  the  midline  the 
greatest  thickness  is  17  mm.  The  excavation  for  the  first  neural  is  narrow  and  the  bone  is  here 
('  mm.  thick. 

The  nuchal  scute  is  32  mm.  long,  5  mm.  wide  in  front,  17  mm.  wide  behind.  The  fore- 
and-aft  extent  of  the  first  marginals  is  41  mm.  The  front  of  the  first  vertebra!  scute  is  51  mm. 
wide.  Backward  it  narrows  slightly,  then  again  expands.  It  extends  backward  on  the  bone 
a  distance  of  38  mm.  The  lateral  angles  are  occupied  by  portions  of  the  first  costal  scutes. 
The  sculpture  consists  of  more  or  less  continuous  ridges  of  quite  uniform  height,  separated 
by  sharp  grooves.  Usually  there  are  5  or  6  of  these  ridges  in  a  line  10  mm.  long.  On  the 
nuchal  scute  area  these  ridges  are  parallel  with  the  midline.  On  the  area  of  the  first  marginal 
they  run  outward  and  forward,  making  an  angle  of  about  25°  with  the  midline.  On  the  area 
covered  by  the  first  vertebral  scute  the  ridges  are  nearly  parallel  with  the  midline,  those  along 
the  lateral  borders  of  the  scute  diverging  somewhat.  The  ridges  of  the  areas  of  the  costal 
scutes  are  the  most  prominent,  and  they  make  an  angle  of  about  45  degrees  with  the  midline. 
Specifically  this  species  is  very  different  from  D.  reticulata.  In  the  latter  the  first  vertebral 
scute  excludes  wholly  the  costal  scutes  from  the  nuchal  bone.  This  bone  is  far  thinner  than  in 
D.  foriJana. 

No  other  bones  in  the  collection  can  be  referred  with  certainty  to  this  species.  In  the 
collection  there  is  the  front  two-thirds  of  the  right  first  costal  plate  of  a  turtle  that  is  provision- 
ally placed  here  (plate  54,  fig.  2;  text-fig. 
450).  It  fits  quite  accurately  against  the 
postero-lateral  border  of  the  type  bone  and 
agrees  with  it  in  sculpture  and  thickness. 
Furthermore,  the  costo-vertebral  sulcus  coin- 
cides with  that  of  the  nuchal.  The  distal 
end  of  the  bone  is  thickened  and  on  the  inner 
surface  excavated  for  the  axillary  buttress. 
A  peripheral,  the  right  second,  may 
belong  to  this  species.  Fig.  450  represents 
the  type  nuchal,  the  first  costal  mentioned 
above,  and  this  peripheral,  placed  in  their 
proper  positions  with  reference  to  one 
another.  The  height  of  the  peripheral  is 
only  34  mm.;  but  when  we  examine  the 
same  bone  in  D.  reticulata  we  find  that  it  too 
is  reduced  in  the  line  from  the  free  border 
to  the  upper  border.  This  is  a  result  of  the 
narrowing  ot  the  carapace.  The  first  costal  scute  descends  on  the  bone  a  distance  of  26  mm. 
The  sculpture  on  its  area  is  directed  downward.  On  the  area  of  the  second  marginal  scute 
the  ridges  run  at  nearly  right  angles  with  the  free  border.  On  the  area  of  the  succeeding 
scute  they  are  directed  downward  and  strongly  backward. 

In  the  Jarman  collection  is  the  portion  of  a  left  xiphiplastron  extending  backward  from 
the  femoro-anal  sulcus.  The  lower  surface  is  ridged  and  grooved  like  the  type  nuchal,  the 
ridges  being  directed  parallel  with  the  midline.  The  hinder  border  of  the  plastron  was  slightly 
notcht,  as  in  D.  reticulata.  At  the  midline  the  bone  is  from  5  mm.  to  7  mm.  thick.  The 
plastron  had  a  length  of  about  290  mm.  The  bone  greatly  resembles  the  corresponding  part 
of  D.  reticulata. 

Genus  TRACHEMYS  Agassiz. 

Shell  varying  from  deprest  to  rather  elevated.  Usually  at  least  traces  of  a  dorsal  keel. 
Neural  plates  hexagonal,  with  broad  end  in  front.  Carapace  sometimes  smooth,  but  more 
usually  with  wrinkles  and  grooves;  occasionally  elaborately  sculptured.  Hinder  border  of 
carapace  usually  more  or  less  serrated.     Plastron  with  a  distinct  lip  in  front  and  a  shallow 


Fig.  450. — Deirochelys  florijana.  Nuchal,  first  and 
second  peripherals,  and  part  of  first  costal.  Xi- 
Partly  restored. 


34^  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

emaigination  behind.  Alveolar  surfaces  of  upper  jaw  each  with  a  longitudinal  ridge,  which 
is  somewhat  denticulated  and  higher  behind  than  in  front.  Choanae  nearly  as  tar  back  as  a 
line  joining  the  middles  of  the  orbits.  Alveolar  surface  of  the  lower  jaw  with  a  longi- 
tudinal groove,  which  is  separated  from  a  shallower  groove  by  a  longitudinal  ridge.  Symphysis 
of  lower  jaw  short,  equal  to  about  half  of  the  distance  between  the  quadrates. 

As  type  of  this  genus  may  be  taken  T .  scripta,  the  species  longest  and  best  known  and 
incidentally  the  one  mentioned  first  by  Agassiz  under  the  name. 

The  species  of  this  genus  are  allied  to  the  species  of  Chrysemys,  but  they  attain  a  larger 
size,  possess  a  more  vigorous  organization,  and  a  fiercer  disposition.  The  wrinkled  and 
furrowed  carapace,  notcht  posteriorly,  distinguishes  the  species  from  those  of  Chrysemys. 
The  plastron  has  a  quite  distinct  lip,  and  this  is  occasionally  slightly  dentated,  but  not  so 
conspicuously  as  in  Chrysemys. 

The  following  analysis  may  aid  in  determining  species  of  which  the  nuchal  bone  is  present: 

1.  All  the  bones  thin  and  little  sculptured htlli 

2.  Nuchal  thick,  strongly  sculptured;   free  border  broader  than  in  T.  sculptu,    with  notch 

for  neural  broader euglypha 

3.  Nuchal  not  so  thick  as  in  euglypha,  about  15  mm.;    free  border  rather  obtuse sculpta 

4.  Notch  for  first  neural  extremely  broad jarmant 

5.  Nuchal  moderately  thick,  10  mm.;  width  in  front  half  the  maximum  width petrolet 

6.  Nuchal  bone  moderately  thick;   width  in  front  three-fifths  the  maximum bisornata 

7.  Epiplastral  lip  spout-like truUa 

Trachemys  hilli  (Cope). 
Plate  55,  figs.  I,  2;   teit-figs.  451,  452. 

Pseudemys  hillii,  CoPE,  Bull.  Geol.  and  Geog.  Surv.  Terrs.,  iv,  1878,  p.  395. 
Trachemys  hillii.  Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  449. 

At  the  present  time  this  species  is  represented  by  only  the  type  specimen.  This  is  in  the 
American  Museum,  as  a  part  of  the  Cope  collection  of  reptiles,  and  has  catalog  number  2425. 
It  was  collected  for  Professor  Cope  in  1877,  by  Mr.  R.  S.  Hill,  in  Decatur  County,  Kansas, 
from  Loup  Fork  deposits.  It  came,  therefore,  from  the  same  locality  and  the  same  level  as  the 
specimens  of  Testudo  orthopygia.  Since  its  arrival  at  the  American  Museum  the  fragments  of 
which  the  specimen  was  composed  have  been  articulated  under  the  supervision  of  the  writer; 
and  the  present  appearance  of  the  specimen  is  shown  on  plate  55.  The  shell  has  retained  the 
plastron  complete,  except  that  the  entoplastron  and  the  epiplastra  are  missing.  Of  the  carapace 
(plate  55,  fig.  i;  text-fig.  451)  the  peripherals  are  present  from  the  rear  to  the  fourth  inclusive 
on  the  right  side  and  to  the  fifth  inclusive  on  the  left  side.  The  third  left  peripheral  also  is 
present.  The  nuchal  is  wanting.  Only  3  complete  neurals  have  been  preserved,  the  fourth, 
the  fifth,  and  the  seventh.  A  portion  of  the  third  is  at  hand.  On  the  right  side  we  have  the 
first,  second,  and  fourth  costals,  and  the  proximal  end  of  the  third.  On  the  left  side  there  are 
present  the  third,  the  fifth,  and  sixth  costals,  with  a  portion  of  the  eighth.  Both  suprapygals 
are  wanting. 

The  whole  length  of  the  shell  was  very  close  to  200  mm.  The  width  at  the  hyohypoplastral 
suture  is  138  mm.  The  width  of  a  specimen  of  T.  rugosa,  from  some  of  the  West  Indian 
islands,  whose  length  of  carapace  is  192  mm.,  is  147  mm.  It  will  be  seen  therefore  that  the 
Loup  Fork  species  is  relatively  more  elongate. 

In  elevation  of  shell  this  species  resembles  T.  elegans  or  T.  rugosa,  rather  than  T .  scripta, 
the  carapace  being  rather  deprest.  The  maximum  height  from  the  bottorn  of  the  shell  is 
75  mm. 

The  fourth  neural  has  a  length  of  17  mm.  and  a  maximum  width  equal  to  the  length. 
The  fifth  neural  is  18  mm.  long  and  16.5  mm.  wide.  The  sixth  neural  had  a  length  of  15  mm. 
and  a  maximum  width  of  16  mm.    The  second  pygal  was  27  mm.  wide. 

Over  the  bridges  a  sharp  keel  intervened  between  the  upper  and  the  lower  portions  of  the 
shell.  The  free  border  of  the  third  peripheral  is  acute.  The  posterior  peripherals  are  only 
slightly  flared  upward.    Their  free  borders  are  thin  and  brought  down  to  an  acute  edge.    The 


EMYDIDj^. 


349 


height  of  the  eleventh  is  29  mm.;  its  width  along  the  free  border,  22  mm.  The  pygal  has  a 
height  (antero-posterior  dimension)  of  23  mm.  and  a  width  of  21  mm.  It  has  a  deep  median 
notch;   and  there  is  a  similar  notch  on  each  side  of  it.    The  interperipheral  notches  are  not 

deep,  and  there  are  no  notches  where  the  sulci  cross  the  borders 
of  the  peripherals.  In  the  latter  respect  this  species  differs  from 
T.  clegans. 

The  bones  of  the  carapace  are  thin,  the  border  ot  the  median 
costals  being  but  little  more  than  2  mm.  thick. 

The  sulci  are  rather  deeply  imprest  on  the  carapace.  The  form 
and  dimensions  of  the  various  scutes  may  be  readily  determined 
from  fig.  451.  The  table  herewith  gives  the  dimensions  of  the 
vertebrals. 

The  arrangement  and  forms  of  the  scutes  closely  resemble 
those  of  the  specimen  of  T .  rugosa  already  mentioned. 

The  sulci  separating  the  costal  from  the  marginal  scutes  are  arranged  somewhat  differently 
in  this  species  from  the  arrangement  in  T.  rugosa  and  f .  scripta.    In  f .  ru^oj^a  the  costo-mar- 


Vertebral 
scute. 

Length 

Width. 

I 

33 

2 

35 

44 

3 

35 

47 

4 

37 

40 

s 

3^ 

1         " 

Figs.  451  and  452. — Trachemys  hilli.     Carapace  and  plastron  of  type.     Xi- 
451.  Carapace.    Front  restored.  452.  Plastron.    Anterior  lobe  partly  restored, 

ginal  sulci  run  along  on  the  peripherals  at  a  considerable  distance  below  the  costo-peripheral 
sutures  from  the  nuchal  to  the  eleventh  peripheral.  Here  the  sulcus  rises  somewhat  and 
crosses  the  midline  on  the  hinder  border  of  the  suprapygal.  In  T.  scripta  the  arrangement  is 
the  same  to  the  eleventh  peripheral,  where  it  remains  low  down  and  crosses  the  upper  third 
of  the  pygal.  In  T.  hilli  from  the  front  of  the  bridge  the  sulci  appear  to  coincide  closely  with 
the  sutures  until  the  seventh  peripheral  is  reacht.  Here  the  sulci  descend  on  the  peripherals, 
but  not  far,  and  they  cross  the  midline  on  the  upper  part  of  the  pygal. 

In  the  case  of  the  neurals  preserved  there  are  some  longitudinal  wrinkles  on  the  hinder 
ends  of  the  third  and  the  fifth,  just  behind  the  sulci  crossing  these  bones.    On  the  costals  is  a 


350  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

number  of  longitudinal  grooves,  which  mark  the  growth  of  the  scutes.  The  deepest  ones  are 
from  5  to  7  mm.  apart  and  appear  to  indicate  the  yearly  increase  in  size.  On  each  peripheral 
behind  the  bridge  we  find  in  front  of  the  sulcus  crossing  it  some  strong  grooves  parallel  with 
the  free  border  of  the  shell;  behind  the  sulcus,  some  more  delicate  grooves  more  nearly  parallel 
with  the  axis  of  the  shell. 

The  length  of  the  plastron  (plate  55,  fig.  2;  text-fig.  452),  from  the  outer  anterior  angle  of 
the  epiplastron  to  the  extremity  of  the  xiphiplastron,  is  165  mm.  In  the  midline,  from  the 
hinder  border  of  the  entoplastron  to  the  notch  in  the  rear,  the  length  is  142  mm.  The  width  of 
the  anterior  lobe  at  the  base  is  91  mm.    The  entoplastron  had  a  width  of  33  mm. 

The  bridge  has  a  width  of  69  mm.     It  rises  rapidly  from  the  bottom  of  the   plastron. 

The  hinder  plastral  lobe  has  a  length  of  75  mm.  and  a  width  of  90  mm.  at  the  base.  Near 
the  suture  between  the  hypoplastra  and  the  xiphiplastra  the  width  is  96  mm.  At  the  end  of  the 
femoro-anal  sulcus  there  is  only  a  slight  notch.  The  free  margins  of  the  plastral  lobes,  so  far 
as  preserved,  are  acute.  The  extremities  of  the  xiphiplastral  bones  are  rounded  and  slightly 
dentated. 

The  humero-pectoral  sulcus  crosses  the  plastron  behind  the  entoplastron.  The  pectoral 
scutes  have  a  width  at  the  midline  of  27  mm.;  the  abdominals,  a  width  of  22  mm.;  the  anals, 
a  width  of  40  mm.    There  are  large  axillary  and  inguinal  scutes. 

The  lower  surface  of  the  plastron  is  delicately  grooved  longitudinally. 

Professor  Cope  mentions  the  presence  of  portions  of  the  skull;  but  there  is  little  more  than 
the  left  quadrate.    It  presents  no  difference  when  compared  with  that  of  T.  rugosa. 

The  shoulder-girdle  and  the  limb  bones  appear  to  resemble  essentially  those  of  the  living 
species  just  mentioned. 

Trachemys  euglypha  (Leidy). 

Plate  54,  fig.  3. 

Emys  euglypha,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1889,  p.  97;  Trans.  Wagner  Free  Instit.,  II,  1889, 
p.  27,  plate  iv,  fig.  I. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  447. 

The  present  species  was  based  on  a  single  bone,  the  nuchal,  of  a  turtle  found  in  the  Peace 
Creek  beds,  Florida.  Dr.  W.  H.  Dall,  of  the  U.  S.  Geological  Survey,  has  examined  these 
deposits  and  pronounct  that  bed,  about  2  feet  in  thickness,  from  which  vertebrate  remains 
have  been  obtained,  to  be  of  older  Pliocene  age.  However,  since  from  that  bed  Dr.  Leidy  has 
described  vertebrates  belonging  to  various  epochs,  from  the  Miocene  to  the  present,  the  correct- 
ness of  the  determination  is  in  question.  The  type  of  the  species  here  described  belongs  to 
the  Wagner  Free  Institute,  Philadelphia,  but  the  writer  has  not  been  able  to  find  it  there. 

Dr.  Leidy  has  referred  his  species  to  the  genus  Emys;  but  it  can  not  belong  there — as  that 
genus  is  understood  at  present.  The  nuchal  resembles  closely  that  of  a  specimen  of  Trachemys 
scripta  now  in  the  American  Museum  of  Natural  History.  From  this,  however,  it  differs 
specifically.  The  length  of  the  bone  at  the  midline  is  58  mm.  The  total  length  of  the  carapace 
of  the  specimen  of  T.  scripta  just  mentioned,  the  length  of  whose  nuchal  is  50  mm.,  is  2IO  mm. 
We  may  therefore  conclude  that  the  carapace  of  Dr.  Leidy's  type  had  a  length  of  about 
290  mm.  The  width  of  the  front  of  the  nuchal  is  37  mm.,  the  greatest  width  73  mm.  This 
border  is  deeply  notcht,  but  the  bottom  of  the  notch  is  divided  by  the  projection  into  it  of  the 
area  occupied  by  the  nuchal  scute,  which  is  11  mm.  wide.  The  thickness  of  the  bone  at  the 
articulation  with  the  first  peripheral  is  21  mm.;  at  the  articulation  with  the  first  neural,  6  mm. 
The  nuchal  of  the  specimen  of  "T.  j^cr//)/a  mentioned  has  a  maximum  thickness  of  only  10  mm. 
a  fact  showing  that  T.  euglypha  had  a  shell  much  thicker  and  heavier  than  that  of  the  living 
species.    The  width  of  the  border  which  articulated  with  the  first  neural  is  23.5  mm. 

The  scutal  sulci  are  deeply  imprest.  The  nuchal  scute  has  a  length  of  20  mm.  and  a  width 
of  ID  mm.,  its  lateral  borders  being  parallel.  That  part  of  the  first  vertebral  scute  which  lies 
on  the  nuchal  bone  is  38  mm.  long.  Measured  anteriorly  between  the  points  where  the  lateral 
sulci  of  the  vertebral  join  the  costo-marginal  scutes,  the  width  of  the  first  vertebral  is  34  mm. 
Measured  posteriorly,  where  the  lateral  sulci  pass  on  to  the  first  costals,  the  width  is  50  mm. 

The  upper  surface  of  this  bone  is  strongly  sculptured,  resembling  somewhat  that  of  T. 
scripta,  but  ridged  and  grooved  more  boldly. 


EMYDID^.  351 

The  writer  has  received  for  examination  from  the  Wagner  Free  Institute  an  injured  nuchal 
bone  (plate  54,  fig.  3)  that  was  collected  at  Peace  Creek,  Florida.  It  has  some  resemblance  to 
that  of  T.  euglvpha.  The  sculpture  is  not  so  strong  and  that  produced  by  the  growth  of  the 
horny  scutes  shows  in  addition  to  that  seen  in  the  type  of  the  species.  On  the  area  of  the  first 
vertebral  scute,  in  the  midline,  there  is  a  high  ridge,  or  carina. 

Trachemys  sculpta  sp.  nov. 
Plate  54,  figs.  4-9. 

In  the  Dr.  Jarman  collection  of  fossil  bones  made  in  Hillsboro  County,  Florida,  now  the 
property  of  Vanderbilt  University,  there  is  a  strongly  sculptured  nuchal  bone  which  represents 
probably  a  hitherto  undescribed  species.  This  nuchal  resembles  much  that  of  T.  bisornata 
(Cope)  and  possibly  belongs  to  it;  but  the  differences  in  form  and  sculpture  and  apparently 
the  differences  of  level  seem  to  justify  regarding  it  as  distinct.  Cope's  bisornata  came  from  the 
Equus  beds,  belonging  to  the  Pleistocene;  the  present  species  from  probably  the  Peace  Creek 
beds,  belonging  to  the  Pliocene. 

The  nuchal  (plate  54,  fig.  4)  has  a  median  length  of  55  mm.;  a  width  of  29  mm.  in  front; 
and  a  maximum  width  of  63  mm.  The  length  and  breadth  are  relatively  the  same  as  in  T. 
bisornata.  The  width  in  front  is  only  50  per  cent,  of  the  length,  while  in  T .  bisornata  it  is 
70  per  cent.  The  anterior  edge  is  obtuse;  in  the  Texas  species  it  is  acute.  The  greatest 
thickness,  just  behind  the  sulcus  between  the  nuchal  and  vertebral  scutes,  is  15  mm.;  that  at 
the  articulation  with  the  first  peripheral,  13  mm.  Where  the  bone  joins  the  first  neural  the 
thickness  is  7  mm.  The  area  of  the  first  vertebral  scute  is  very  convex,  producing  a  broad 
rounded  carina. 

The  sulci  are  sunken  to  a  great  depth.  The  nuchal  scute  is  long  and  narrow,  and  its  area 
is  raised  into  a  strong  ridge.  The  first  vertebral  is  24  mm.  wide  in  front  and  it  expands  poste- 
riorly. The  front  of  each  first  marginal  on  this  bone  is  nearly  one-half  the  width  of  the  front  of 
the  first  vertebral.  In  T .  bisornata  it  is  not  one-third.  The  areas  of  the  first  marginals  are 
sculptured  into  prominent  ridges  and  grooves.  In  T .  bisornata  these  are  feeble  and  the  lines 
of  growth  of  the  scutes  are  more  prominent.  Where  the  ridges  show  in  bisornata  they  diverge 
at  a  greater  angle  from  the  midline.  On  the  area  occupied  by  the  first  vertebral  of  T .  sculpta 
there  are  some  ridges  running  parallel  with  the  midline.  On  the  area  occupied  by  each  first 
marginal  there  are  5  or  6  ridges  which  run  outward  and  backward. 

Plate  54,  fig.  5,  represents  the  distal  end  of  probably  the  third  costal.  Its  width  is  45  mm. 
at  the  distal  border,  but  it  narrows  upward.  The  fragment  belongs  to  the  Jarman  collection, 
in  Vanderbilt  University. 

Plate  54,  figs.  6,  7,  represents  two  neural  bones  found  with  others  of  the  same  kind  in  the 
Jarman  collection.  The  one  with  the  sulcus  crossing  it  has  a  length  of  35  mm.  and  a  thickness 
where  it  joined  the  costal  of  15  mm.     They  may  or  may  not  belong  to  the  species  here  described. 

Figs.  8  and  9  of  plate  54  represent  two  costals  which  may  belong  to  the  present  species. 
Fig.  8  is  probably  the  right  fourth  costal  and  lacks  the  proximal  half.  The  thickness  at  the 
distal  end  is  8  mm.  The  original  of  fig.  9  is  the  left  sixth  costal.  It  is  thickened  on  the  anterior 
border  of  the  distal  end  to  13  mm.,  the  posterior  border  at  the  distal  end  being  only  9  mm. 

The  type  nuchal  resembles  rather  closely  T.  euglypha  (Leidy);  but  the  front  of  the  nuchal 
of  the  latter  is  broader  and  more  deeply  notcht  and  the  excavation  for  the  first  neural  is  broader. 
The  nuchal  scute  is  broader  and  shorter.  The  greatest  thickness  is  21  mm.,  far  exceeding  that 
of  T.  sculpta. 

Trachemys  ?  jarmani  sp.  nov. 

Plate  54,  figs.  10-12. 

The  species  to  which  the  above  name  is  given  is  based  on  a  complete  nuchal  bone,  a  part 
of  the  Jarman  collection  of  fossil  bones  obtained  in  Hillsboro  County,  Florida,  by  Dr.  W.  H. 
Jarman,  and  presented  by  him  to  Vanderbilt  University,  Nashville,  Tennessee.  The  age  of 
the  beds  is  somewhat  uncertain,  but  they  are  probably  of  the  same  age  as  the  Peace  Creek 
beds.     The  species  is  referred  provisionally  to  Trachemys. 

The  nuchal  (plate  54,  fig.  10)  is  remarkable  on  account  of  the  shortness  of  its  hinder 
portion  and  the  evidence  which  it  affords  that  the  neural  bones  were  very  broad.     The  total 


352  FOSSIL    TURTLES    OK    NORTH    AMERICA. 

length  of  the  bone  is  6 1  mm.  The  front  border  is  excavated  shghtly;  the  hinder  border  widely, 
for  the  reception  of  the  first  neural.  The  length  along  the  midline  is  47  mm.  The  width  of  the 
anterior  border  is  37  mm.;  the  greatest  width,  80  mm.  The  anterior  border  is  acute.  From 
this  the  bone  thickens  backward  on  the  under  side  a  distance  of  47  mm.,  where,  at  the  mid- 
line, it  is  20  mm.,  at  the  border  for  first  peripheral,  25  mm.;  then  it  thins  rapidly  to  the  hinder 
border,  where  it  is  13  mm.  at  the  midline,  10  mm.  at  the  sides  of  the  notch  for  first  neural. 

In  this  species  the  front  of  the  first  neural  is  on  a  line  with  the  lateral  angles  of  the  bone, 
an  unusually  forward  position.  The  neural  must  have  been  of  uncommon  width,  not  less  than 
50  mm.,  occupying  thus  five-eighths  of  the  width  of  the  nuchal.  This  first  neural  must,  too, 
have  been  13  mm.  thick  in  front. 

The  nuchal  scute  is  34  mm.  long,  6  mm.  wide  in  front,  12  mm.  wide  posteriorly.  On  the 
inner  side  of  the  bone  it  extended  backward  21  mm.  The  first  marginal  had  an  extreme  fore- 
and-aft  extent  of  40  mm.  The  front  of  the  first  vertebral  scute  is  41  mm.  wide.  It  extended 
forward  on  the  nuchal  only  13  mm.  at  the  midline.  The  lateral  angles  of  the  bone  are  occupied 
by  portions  of  the  first  costal  scutes. 

The  upper  surface  of  the  bone  is  beautifully  sculptured  with  grooves  and  sharp,  inter- 
rupted ridges.  On  the  nuchal  scute  area  the  ridges  run  parallel  with  the  midline.  On  the 
areas  of  the  first  marginal  scutes  the  ridges  are  short  and  suddenly  interrupted  at  their  anterior 
ends.  They  run  forward  and  outward,  making  an  angle  of  about  25°  with  the  midline.  The 
ridges  on  the  front  of  the  first  vertebral  scute  area  are  short,  almost  tubercular,  and  are  parallel 
with  the  midline.  On  the  areas  of  the  first  costal  scutes  the  ridges  are  coarser  and  they  run 
outward  and  backward,  making  an  angle  of  64°  with  the  midline. 

No  other  parts  are  known  that  can  be  referred  with  certainty  to  this  species.  No  neurals 
in  the  collection  are  broad  enough  to  belong  to  it.  A  peripheral  (plate  54,  fig.  11),  the  right 
eighth,  appears  to  be  worthy  of  reference  here  on  account  of  its  sculpture  and  thickness.  It 
has  a  height  of  50  mm.,  a  width  of  39  mm.  below,  and  of  33  mm.  above.  The  free  border  is 
acute.  From  this  the  bone  thickens  rapidly,  so  that  near  the  middle  of  the  height  it  is  26  mm. 
where  it  joined  the  sixth  peripheral;  ig  mm.  where  it  articulated  with  the  ninth.  On  the  inside 
of  the  bone,  at  the  upper  posterior  angle,  is  a  pit  for  the  end  of  a  rib,  probably  the  sixth.  On 
the  articular  face  for  union  with  the  fifth  peripheral  there  is  a  striated  depression,  which  appears 
to  have  been  a  part  of  a  pit  between  the  two  peripherals  for  a  rib,  the  fifth.  On  the  same  face, 
nearer  the  inner  surface  of  the  bone,  is  a  rounded  smooth  depression  which  indicates  that  the 
sternal  chamber  reacht  this  face.  Still  nearer  the  inner  surface  of  the  bone  is  an  excavation 
apparently  for  a  part  of  the  inguinal  buttress. 

The  sculpture  of  this  bone  resembles  that  of  the  nuchal  of  Deirochelys  jlortdana.  How- 
ever, the  thickness  appears  to  be  too  great  for  the  latter  species. 

A  left  third  costal  in  the  collection  is  referred  provisionally  to  this  species  (plate  54,  fig. 
12).  It  presents  the  proximal  end.  The  width,  just  outside  the  costo-vertebral  sulcus,  is  38 
mm.  It  belonged  to  an  individual  with  a  carapace  about  340  mm.  long.  The  most  conspicuous 
character  is  the  great  thickness  at  the  suture  with  the  neurals,  this  being  20  mm.  The  thick- 
ness diminishes  to  the  costo-vertebral  sulcus  where  it  is  9  mm.  The  thickening  has  produced 
a  broad  keel  along  the  back.     The  sculpture  agrees  well  with  that  of  the  type  nuchal  bone. 

Trachemys  petrolei  (Leidy). 
Plate  46,  figs.  3,  4. 

Emys  petrolei,  Leidy,  Proc.  Acad.  Nat.  Sci.  Fhila.  1868,  p.  176;  Contrib.  Ext.  Vert.  Fauna  West.  Terrs., 
187^,  pp.  260,  340,  plate  ix,  fig.  7. — Cope,  Ext.  Bat.,  Rept.,  and  Aves  N.  A.,  1869,  p.  128. — Hay, 
Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  448. 

Dr.  Joseph  Leidy  states  in  his  original  description  of  this  species  that  the  types  had  been 
submitted  to  him  for  examination  by  Messrs.  George  N.  Lawrence  and  D.  G.  Elliot,  of  New 
York,  and  that  they  had  been  previously  presented  to  the  New  York  Lyceum  of  Natural 
History  by  Mr.  Robertson.  The  specimens  were  reported  to  have  been  obtained  from  blue 
clay  and  sand  beneath  a  bed  of  bitumen,  in  Hardin  County,  Texas.  The  age  is  Pleistocene. 
These  bones  and  most  of  those  accompanying  them  are  impregnated  with  bitumen.  They 
now  belong  to  the  .'\merican  Museum  of  Natural  History  and  have  the  catalog  number  3933. 


EMYDID^.  353 

The  type  of  the  species  Emys  petrolei  Leidy  must  be  regarded  as  being  the  two  epiplastrals 
figured  by  him  in  1873.  Leidy  mentions  and  briefly  describes  a  nuchal  bone  and  a  hypo- 
plastral,  but  there  is  no  certainty  that  these  belonged  to  a  member  of  the  same  species.  The 
two  epiplastrals  are  the  right  and  the  left,  but  they  did  not  belong  to  the  same  individual. 
Dr.  Leidy's  figures  present  a  view  of  the  lower  surfaces;  the  figures  here  presented  (plate  46, 
fig.  3)  represent  the  upper  surfaces. 

The  individuals  to  which  these  epiplastrals  belonged  appear  to  have  had  plastra  about 
200  mm.  long,  tho  perhaps  somewhat  less.  Dr.  Leidy  thought  that  the  animal  belonged 
to  the  genus  Trachemys  and  compared  it  especially  with  T.  scrtpta  (T.  scahra).  When 
compared  with  a  specimen  of  the  latter  whose  plastron  is  270  mm.  long  there  appear  decided 
differences. 

The  epiplastral  lip  of  T .  petrolei  was  52  mm.  wide;  that  of  the  specimen  of  'T .  scrtpta 
referred  to  is  60  mm.  wide,  a  difference  due  to  difference  of  size  of  the  individuals.  The  lip  of 
T.  petrolei  is  directed  forward;  that  of  T.  scrtpta  is  rolled  downward  in  front.  The  thickness 
of  the  epiplastrals  of  T.  petrolei  at  the  symphysis  is  1 1.5  mm.,  somewhat  more  than  that  of  the 
specimen  of  T.  scripta,  altho  the  latter  is  so  much  larger.  The  backward  extension  of  the  lip, 
along  the  midline  on  the  upper  surface,  is  29  mm.  in  T.  petrolet;  in  T.  scripta,  only  23  mm. 
In  the  former  the  thickening  referred  to  ends  posteriorly  much  more  abruptly  than  it  does  in 
T.  scripta.  In  both  species  it  may  be  observed  that  the  gular  scutes  overlapt  the  anterior  ends 
of  the  entoplastron.  There  can  be  no  doubt  that  T.  petrolei  is  a  species  distinct  from  both  T. 
scripta  and  T.  elegatis.  The  latter  species  occupies  at  present  the  region  where  T .  petrolet 
was  found.  T .  elegans  has  a  very  different  epiplastral  lip,  this  being  wider;  concave  above 
so  as  to  resemble  a  spout;  and  not  so  thick.  In  both  T.  scrtpta  and  T.  elegans  the  gular  sulci 
on  the  upper  surface  of  the  epiplastrals  run  outward  and  forward,  while  in  T .  petrolet  they  run 
directly  forward. 

It  will  be  observed  from  the  figures  that  there  are  some  differences  between  the  two  epi- 
plastra,  but  these  are  not  sufficient  to  indicate  distinct  species. 

The  nuchal  bone  (plate  46,  fig.  4)  mentioned  by  Dr.  Leidy  has  a  length  of  46  mm.  and  a 
maximum  breadth  of  50  mm.  The  width  at  the  free  border  has  been  25  mm.  The  border  for 
articulation  with  the  first  peripheral  is  very  concave.  Where  the  sulci  bounding  the  nuchal 
scute  crost  the  free  border  there  are  very  deep  notches,  so  that  the  nuchal  scute  projects  as  a 
prominent  tooth.    The  greatest  thickness  of  the  nuchal  bone  is  10  mm. 

The  nuchal  scute  is  20  mm.  long  and  7  mm.  wide  at  the  base.  The  width  of  the  scute  on 
the  under  side  of  the  bone  is  slightly  less.  In  T.  scripta  the  scute  is  nearly  twice  as  wide  on 
the  lower  side  as  on  the  upper.  In  T.  elegans  the  lower  side  is  about  one-half  wider  than  the 
upper.  The  first  vertebral  scute  of  T.  petrolei  has  a  width  anteriorly  of  27  mm.,  and  it  has 
grown  wider  posteriorly.  In  the  specimen  of  T.  scripta  mentioned,  the  first  vertebral  is  only 
18  mm.  wide  anteriorly.  In  the  midline  of  the  fossil  nuchal  there  is  a  mere  suggestion  of  the 
presence  of  a  carina;  in  T.  scripta  the  carina  is  very  distinct.  As  to  the  sculpture,  there  are 
faint  ridges  which  occupy  the  same  positions  as  the  much  more  distinct  ones  in  T .  scrtpta  and 
T .  elegans. 

The  hypoplastral  bone  mentioned  by  Dr.  Leidy  is  present,  as  well  as  a  second  belonging 
to  another  individual.  These  are  much  thicker  than  the  corresponding  bones  of  T.  elegans 
and  somewhat  thicker  than  those  of  T.  scripta.  Here  again  we  are  uncertain  whether  these 
bones  belong  to  the  same  species  as  the  epiplastra. 

The  nuchal  bone  above  described  resembles  that  of  the  species  described  by  Cope  under 
the  name  Pseudemys  bisornatus,  here  called  Trachemys  bisornata.  We  must  therefore  consider 
the  possibility  that  Cope's  species  is  identical  with  that  described  earlier  by  Leidy.  This 
question  can  not  be  settled  until  additional  materials  have  been  collected  at  one  or  both  of  the 
localities,  Hardin  County  and  Atascosa  County. 

Trachemys  bisornata  (Cope). 
Plate  56,  fig.  I. 

Pseudemys  bisornatus.  Cope,  Proc.  Amer.  Philcs.  Soc,  xvii,  1878,  p.  228. 
Trachemys  hisornatn.  Hay,  Bibliog.  and  Cat.  Koss.  Vert.  N.  A.,  1902,  p.  449. 

23 


354 


KOSSII,    TURTLKS    OK    NORTH    AMKRICA. 


This  species  is  stated  to  be  based  on  portions  of  3  individuals,  which  were  collected  hir 
Professor  Cope  by  Mr.  G.  W.  Marnock,  in  southwestern  Texas.  The  beds  are  stated  to 
belong  to  the  Pliocene;  but  now  they  are  regarded  as  Pleistocene. 

In  the  collection  of  the  Philadelphia  Academy  there  is  found  a  part  of  the  anterior  half  of 
a  carapace  which  evidently  belongs  to  this  species  and  which  is  probably  one  of  the  three  por- 
tions referred  to  by  Cope  in  his  description.  It  is  labeled  in  Cope's  handwriting,  and  is  stated 
to  have  been  collected  by  G  .W.  Marnock,  from  the  Pliocene  beds  of  Atascosa  County,  Texas. 
Terra  bene  marnochii  was  described  by  Cope  on  the  page  following  the  description  of  the  present 
species  and  was  said  to  come  from  the  same  formation.  From  the  American  Naturalist, 
vol.  XXIII,  1889,  page  161,  we  learn  that  the  latter-named  species  was  found  in  the  Equus  beds. 
From  these  Equus  beds  we  have  therefore  TestuJo  atascostv  Hay,  Terrapene  tnarriochti  (Cope), 
Trachemys  bisornata  (Cope)  and  T.  trtilla  Hay. 

The  specimen  (plate  56,  fig.i)  in  the  Philadelphia  Academy  consists  of  the  nuchal,  the  first 
right  peripheral,  the  first  and  second  right  costals,  parts  of  the  third  and  fourth  right  costals, 
the  first,  second,  fourth,  and  fifth  neurals,  and  the  proximal  portions  of  the  first  and  second 
left  costals.  The  third  neural  is  missing,  but  its  dimensions  and  form  are  easily  determined. 
The  nuchal  resembles  that  of  T.  scrtpta.  In  front  it  is  thin-edged  and  sharp.  It  is  slightly 
notcht  at  the  ends  of  the  sulci  bounding  the  nuchal  scute,  and  between  the  ends  of  these  sulci 
are  3  teeth.  Its  length  along  the  midline  is  49  mm.;  its  width  anteriorly,  34  mm.;  the  max- 
imum width,  55  mm.     The  table  herewith  gives  the  dimensions  of  the  neurals  represented. 

The  thickness  of  the  fourth  neural  is  7.5  mm.  The  first  is 
oval.  The  second  is  broadest  in  front  and  deeply  excavated  to 
receive  the  first.  The  other  neurals  are  hexagonal,  with  the  broad 
end  in  front. 

The  second  costal  is  26  mm.  wide  near  its  neural;  the  third 
is  28  mm.  wide;  the  fourth,  23  mm.  They  are  rather  thick  proxi- 
mally,  as  is  indicated  by  the  thickness  of  the  fourth  neural. 

The  nuchal  scute  is  19  mm.  long  and  10  mm.  wide  posteriorly. 
The  first  vertebral  is  46  mm.  long,  33  mm.  wide  in  front,  40  mm. 
behind.  The  second  is  52  .mm.  long  and  50  mm.  wide.  The  third  is  43  mm.  long,  54  mm. 
wide.    The  sulci  are  deeply  imprest. 

Along  the  midline  there  appears  a  broad  and  shallow  groove,  beginning  with  the  first 
neural,  showing  most  conspicuously  on  the  second,  and  persisting  on  the  fourth  and  fifth. 
There  is  only  a  suggestion  of  a  median  carina. 

The  ornamentation  of  the  carapace  has  been  described  by  Cope,  and  his  description 
applies  to  the  specimen  here  considered.  The  whole  surface  of  the  carapace,  as  tar  as  known, 
is  sculptured  into  ridges  and  grooves.  The  areas  occupied  by  the  vertebral  scutes  are  smoothest, 
but  here  too  we  find  some  sculpture.  On  those  costal  bones  which  are  traverst  by  the  inter- 
costal sulci  we  find  that  the  area  in  front  of  the  sulcus  presents  sharp  ridges,  some  ot  which 
run  at  right  angles  with  the  sulcus,  while  others  cross  these  parallel  with  the  sulcus.  Behind 
the  sulcus  the  ridges  run  only  at  right  angles  with  the  sulcus,  and  these  ridges  are  broader  than 
those  in  front  of  the  sulcus.  Those  costals  which  are  not  traverst  by  the  intercostal  sulci  are 
ornamented  more  like  the  anterior  portion  of  the  costal  plates  first  described.  The  ornamenta- 
tion may  be  otherwise  described  as  follows:  Along  the  front  of  each  scutal  area  there  is  a  band 
of  broad  ridges.  Most  of  the  remainder  of  the  area  is  occupied  by  ridges  and  grooves  running 
parallel  with  the  length  of  the  animal  and  crost  by  a  system  of  less  conspicuous  ridges.  The 
lower  border  of  the  costal  scutal  area,  that  formed  by  the  upper  borders  of  the  peripheral  bones, 
is  occupied  by  coarse  ridges  at  right  angles  with  the  length  of  the  animal. 

The  sculpture  of  the  carapace  of  this  tortoise  has  been  compared  by  Cope  to  that  found  on 
T .  elegans.  It  appears  to  be  still  more  like  that  of  a  large  specimen  of  T .  scripta  now  in  the 
American  Museum  of  Natural  History.  It  can  hardly  be  doubted  that  the  fossil  species  is 
closely  related  to,  perhaps  the  immediate  ancestor  of,  both  T .  elegans  and  T .  scripta.  It  has 
differed  from  T.  elegans  in  having  a  considerably  thicker  and  more  boldly  sculptured  carapace; 
from  T.  scripta  apparently  in  having  a  less  well-defined  dorsal  carina.  Remarks  on  the  pos- 
sible identity  of  this  species  with  Trachem\s  petrolei  will  be  found  on  page  353. 


Neural. 

Length. 

Width. 

I 

30 

17 

2 

10 

20 

3 

»5 

^3 

4 

21 

^4 

5 

22 

22 

EMYDID^;. 


355 


Trachemys  truUa  sp.   nov. 
Plate  56,  figs.  2-6;    tc«-fig.  453. 

The  type  of  this  species  is  No.  3934  of  the  American  Museum  of  Natural  History.  It  con- 
sists of  portions  of  both  epiplastra  of  a  specimen  which  accompanied  the  type  of  Dr.  Leidy's 
Emys  (Trachemys)  petrolei;  and  was  therefore  obtained  from  the  Pleistocene  deposits  of 
Hardin  County,  Texas.  Without  additional  materials  it  is  not  possible  to  determine  with 
exactitude  the  generic  relations  of  the  species,  but  the  parts  resemble  most  those  of  Trachemys 
elegans,  a  present  inhabitant  of  that  region  of  the  country. 

The  bones  forming  the  type  are  almost  exactly  the  size  of  those  of  a  specimen  of  7".  elegans 
whose  length  of  carapace  is  240  mm.  From  the  latter  it  differs  in  having  a  much  narrower  lip, 
that  of  T.  elegans  being  59  mm.  wide,  that  of  T.  trulla,  41  mm.  wide.  The  lip  of  the  latter 
(plate  56,  figs.  2,  3)  is  also  of  a  somewhat  different  form.  In  T .  elegans,  seen  from  above,  the 
gulo-humeral  sulci  are  directed  outward  and  forward  to  the  border  of  the  epiplastral  bones, 
the  lip  projects  rather  abruptly,  and  it  is  subtruncated.     In  T.  trulla  each  gulo-humeral  sulcus, 

on  the  upper  surface  of  the  bone,  runs  directly  forward,  the  lip 
projects  gradually  from  the  border  of  the  bone,  and  rounds  for- 
ward and  inward  to  the  midline.  The  free  border  of  the  lip  of 
T.  elegans  is  usually,  if  not  always,  dentated;  that  of  T .  trulla  is 
smooth  in  outline. 

The  lips  of  both  T.  elegans  and  of  T .  trulla  are  excavated  on 
the  upper  surface  so  as  to  resemble  somewhat  the  spout  of  a 
pitcher.  In  T.  trulla  the  sides  of  this  spout  descend  more 
abruptly  than  in  the  case  of  the  observed  specimen  of  T.  elegans. 
These  sides  rise  each  as  a  ridge  some  distance  above  the  level  of 
the  gulo-humeral  sulcus  and  parallel  with  it.  Anteriorly  each  ridge 
descends  into  the  free  border  of  the  lip.  At  the  hinder  end  of  each 
ridge,  at  a  lower  level,  is  a  deep  pit. 

At  the  midline  on  the  upper  surface  the  gular  scutes  extend 
backward  a  distance  of  15  mm.  At  the  hinder  end  of  the  epi- 
plastron  the  width  of  the  humerals  was  about  15  mm. 

Seen  from  below,  the  middle  of  the  lip  descends  little  below 
the  general  level  of  the  epiplastral  bones.  The  gulo-humeral  sulci 
are  deeply  imprest  and  they  extended  backward  on  the  entoplas- 
tron.  The  length  of  the  sulcus  separating  the  gulars  was  32  mm. 
The  suture  between  the  two  epiplastrals  has  a  length  of  27  mm. 
The  thickness  of  the  bones  at  the  symphysis  is  7  mm.  The  free 
border  of  the  epiplastron,  where  it  joins  the  hyoplastron,  is  acute; 
on  each  side  of  the  gulo-humeral  sulcus,  thickened  and  rounded; 
near  the  midline,  again  acute. 

With  the  bone  described  above  are  a  right  hyoplastron,  a 
right  hypoplastron,  and  a  left  xiphiplastron  which  are  supposed 
to  have  belonged  to  the  same  species.  These  bones  are  represented  by  figs.  4,  5,  and  6  of 
plate  56. 

Text-fig.  453  is  a  restoration  of  the  plastron,  made  up  from  the  various  bones  that  are 
described  above. 

This  figure  shows  the  relative  dimensions  of  the  bones  and  the  positions  of  the  scutes. 
Fig.  4  of  the  plate  cited  presents  a  view  of  the  upper  surface  of  the  hyoplastron,  fig.  5  of  the 
hypoplastron,  and  fig.  6  of  the  xiphiplastron.  The  relative  width  of  the  beveled  surfaces  on 
the  upper  side  of  these  bones  is  displayed.  All  the  free  borders  are  acute,  especially  that  of  the 
xiphiplastron.  The  notch  at  the  rear  of  the  hinder  lobe  was  broad,  but  very  shallow.  The 
hyoplastron  is  7  mm.  thick  on  the  midline,  at  the  middle  of  the  length.  The  anterior  end  of 
the  hypoplastron,  on  the  midline,  is  7  mm.  thick;  but  further  backward  becomes  10  mm.  The 
anterior  end  of  the  xiphiplastron,  at  the  summit  of  the  bevel,  is  7  mm.  thick.  The  bones  are 
not  sculptured. 


Fig.  453. — Trachemys  trulla. 
Plastron  restored  from 
bones  figured  on   plate   56. 


j^6  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

Genus  PSEUDEMYS  Gray. 

Shell  in  general  like  that  of  Trachemys.  Triturating  surface  of  the  upper  jaw  broad  all 
round,  with  a  strongly  developt  tuberculated  median  ridge.  Lower  jaw  with  broad  surface 
and  a  median  ridge;  its  lower  surface  flat. 

Type:    Pseudemys  rubrtvetUris  Leconte. 

Pseudemys   extincta  sp.  nov. 

Plate  54,  fig.  13. 

The  basis  of  the  present  species  is  a  nuchal  bone  belonging  to  the  Jarman  collection,  the 
property  of  Vanderbilt  University.  The  collection  was  made  in  Hillsboro  County,  Florida, 
from  beds  belonging  probably  to  the  Peace  Creek  formation. 

This  nuchal  is  referred  to  Pseudemys  because  of  its  resemblance  to  that  of  P.  rubriventris, 
of  the  Southern  States.  The  hinder  border  is  somewhat  water-worn,  but  it  evidently  follows 
closely  the  sutural  edge.  The  median  length  is  62  mm.;  the  frontal  width,  33  mm.;  the 
maximum  width,  70  mm.  The  anterior  border  is  acute.  From  this  the  bone  thickens  back- 
ward about  30  mm.,  where  is  becomes  18  mm.  at  the  midline,  15  mm.  at  the  articulation  with 
the  first  peripheral.  Where  the  bone  joins  the  first  neural  it  is  5  mm.  thick.  The  nuchal  scute 
is  26  mm.  long,  9  mm.  wide  in  front,  19  mm.  behind.  The  first  vertebral  is  48  mm.  wide  in 
front,  contracting  behind  this,  then  again  expanding.  The  first  marginal  has  a  length,  fore  and 
aft,  of  37  mm.     Its  union  with  the  first  costal  on  this  bone  is  only  10  mm.  long. 

The  upper  surface  of  this  bone  is  in  general  smooth,  but  there  are  traces  of  a  sculpture, 
produced  by  the  growth  of  the  scutes.  On  the  nuchal  area  the  low  ridges  run  parallel  with  the 
midline;  so  also  do  those  on  the  area  of  the  first  vertebral.  Those  on  the  areas  of  the  first 
marginals  run  outward  and  forward  at  an  angle  of  about  45°  with  the  midline.  The  ridges  on 
the  areas  of  the  first  costals  run  outward  and  backward  at  a  small  angle  with  the  midHne. 

With  the  other  bones  from  the  region  about  Tampa  Bay  there  come  many  portions  of 
plastrons,  some  of  which  probably  belong  to  the  present  species.  However,  there  is  no  way 
for  connecting  any  plastral  lip,  for  instance,  with  any  nuchal  bone.  The  writer  describes, 
from  that  region,  a  number  of  species  founded  on  nuchal  bones,  a  quite  characteristic  part  of 
the  skeleton.  It  remains  for  collectors  and  students  to  find  and  record  other  bones  in  their 
natural  association  with  these  various  nuchals. 

Pseudemys  caelata  sp.  nov. 
Plate  57,  figs.  1-6;   teit-fig.  454. 

This  name  is  based  on  some  bones  which  belong  to  the  U.  S.  National  Museum.  They 
were  obtained  from  "Mason's  bone  bed,"  somewhere  in  Levy  County,  Florida,  and  are 
supposed,  but  not  known,  to  belong  to  the  Pleistocene  epoch.  They  may  belong  to  the  Peace 
Creek  formation.  The  bones  bear  the  U.  S.  National  Museum's  number  2508.  They  appear 
to  be  parts  of  at  least  2  individuals,  one  considerably  larger  than  the  other.  Of  the  larger 
individual  there  are  present  the  nuchal;  the  distal  end  of  the  third  costal,  that  of  probably 
the  left  side;  the  left  fifth  costal;  the  proximal  end  of  the  seventh  right  costal;  the  third  left 
peripheral;  three  posterior  peripherals;  the  left  epiplastron;  and  the  left  hypoplastron. 
Should  it  happen  that  more  than  one  species  is  here  included,  the  nuchal  bone  is  to  be  regarded 
as  the  type. 

This  species  is  conspicuous  for  its  sculpture,  which  resembles  that  of  Trachemys  scripta, 
now  living  in  the  Southern  States. 

The  nuchal  bone  (plate  57,  fig.  i)  is  45  mm.  long  and  23  mm.  wide  in  front,  and  55  mm. 
wide  where  widest.     The  free  border  is  acute;    the  greatest  thickness,  10  mm. 

The  third  costal  is  35  mm.  wide  distallv  and  nearly  5  mm.  thick  at  the  sutural  edge.  The 
fifth  costal  (fig.  2)  is  25  mm.  wide  and  j  mm.  thick  at  the  costo-vertebral  sulcus,  and  32  mm. 
wide  at  the  distal  end.  The  costo-vertebral  sulcus  crosses  the  proximal  end  at  about  10  mm. 
from  the  articulation  with  the  neural.  On  the  inner  side  of  the  distal  half  there  is  a  prominent 
ridge.  In  the  lower  end  of  this  ridge  is  an  excavation  for  the  inguinal  buttress.  This  buttress 
lose  about  20  mm.  above  the  lower  border  of  the  costal.    The  seventh  costal  is  15  mm.  wide 


EMYDID^.  357 

at  thecosto-vertebial  sulcus.  The  third  left  peripheral  ffig.  3)  has  a  length  ot  32  mm.  along 
the  free  border,  and  a  height  of  30  mm.  The  extreme  width  of  the  face  which  joins  the  .second 
peripheral  is  20  mm. 

Fig.  4  of  the  plate  cited  illustrates  the  tenth  left  peripheral.  It  is  21  mm.  along  the  acute 
free  edge,  35  mm.  high,  and  it  has  a  maximum  thickness  of  7  mm.  The  upper  surface  is  con- 
cave up  and  down  and  slightly  convex  fore  and  aft.  It  does  not  appear  to  have  formed  a 
jagged  suture  with  the  contiguous  ends  of  the  costals. 

The  dimensions  of  some  of  the  scute  areas  can  be  only  approximately  determined.  The 
nuchal  scute  has  a  length  of  17  mm.  and  a  width  of  10  mm.  The  anterior  end  of  the  first 
vertebral  has  a  width  of  37  mm.  The  anterior  end  of  the  fourth  vertebral  scute  overlapt  the 
fifth  costal  bone  a  distance  of  17  mm.  Its  width  was  therefore  34  mm.  plus  the  as  yet  unknown 
width  of  the  neural,  amounting  to  probably  45  mm. 

The  sculpture  of  the  carapace  may  now  be  briefly  described.  On  the  nuchal  bone  the  area 
occupied  by  the  first  vertebral  scute  is  ornamented  with  longitudinal  ridges,  5  in  a  line  10  mm. 
long.  These  ridges  are  more  or  less  interrupted  by  the  grooves  concentric  with  the  anterior 
border  of  the  scute.  On  the  area  of  the  first  marginal  scute  the  ridges  diverge  at  an  angle 
with  the  midline  and  are  interrupted  by  grooves  parallel  with  the  midline.  The  distal  half  of 
the  third  costal  is  markt  by  ridges  running  downward  and  obliquely  toward  one  edge  of  the 
bone.  These  again  are  crost  by  ridges  parallel  with  the  distal  end  of  the  bone.  The  fifth 
costal  is  similarly  sculptured  on  the  distal  end,  but  the  ridges  are  more  irregular.  The  middle 
third  has,  along  the  anterior  border,  some  strong  ridges  and  grooves  at  right  angles  with  the 
sutural  border,  while  the  hinder  half  is  occupied  by  conical  elevations  having  little  regularity-. 

^  On   the  third   peripheral   bone  the  area   above  the    costo- 

.X,,^  marginal    sulcus    is    markt    by  ridges   running   downward; 

./       ^^^  the  area  in  front  of  the  intermarginal  sulcus  shows   strong 

t  \  ridges  and  grooves  directed  forward;   while  the  area  behind 

/  \  this  sulcus  presents  narrower  and  closer  ridges,  broken  by 

>J  ^-j^\^       cross  furrows.    The  hinder  peripherals  have  the  area  in  front 

\  ^J  of  the  descending  sulcus  markt  by  both  vertical   and   hori- 

\^^^y  zontal  ridges;  while  the  posterior  half  presents  coarse  ridges 

/  that  run  downward  and  backward. 

The  plastron   possest  an  anterior  lip   (fig.  454)  whose 

ViG.  4S4-—PseuJemysca^lnta.   Left     ^{jj^  was   54   mm.     Its   free   border  is  subacute.     On   the 

lialf  of  lower  surface  of  plastral  ^-^^  ^^j- ^^^  ,•     ^j^^  horn-covered  area  extends  backward 

lip  of  type.     Xi     U.  S.  N.  M.        7.  .    ,        ^     „r,  ,      ,  ■   ■       i.i  .      1     . 

'  -'  ■*  a  distance  of  15  mm.    Where  the  bone  joined  the  entoplastron 

the  thickness  is  10  mm.    The  gular  scutes  overlapt  the  entoplastron. 

The  hypoplastron  (plate  57,  fig.  5)  is  72  mm.  long,  and  it  had  a  width  of  55  mm.  at  the 
inguinal  notch.  At  the  midline,  near  the  anterior  end,  the  bone  is  13  mm.  thick.  The  free 
border  of  the  bone  is  acute.  The  horn-covered  band  on  the  upper  surface  is  22  mm.  wide  at 
the  hypoxiphiplastral  suture. 

The  area  occupied  by  the  gular  scutes  is  ornamented  with  ridges  and  grooves  which  are 
nearly  parallel  with  the  gulo-humeral  sulcus.  The  markings  on  the  area  of  the  humeral  scute 
are  indistinct.  The  hypoplastron  is  distinctly  sculptured.  On  the  area  of  the  abdominal  scute 
are  short  vermicular  ridges,  reminding  one  of  the  carapace  of  a  trionychid.  On  most  of  the 
area  of  the  femoral  scutes  the  sculpture  suggests  a  tiled  roof;  but  on  the  outer  half  there 
are  distinct  longitudinal  ridges,  7  of  them  in  a  line  10  mm.  long. 

Fig.  6  of  plate  57  shows  the  left  first  costal  of  a  smaller  individual.  It  is  markt  by  radiating 
and  concentric  grooves  and  ridges.  On  the  inner  surface  is  an  excavation  for  the  inguinal 
buttress.    This  buttress  rose  about  15  mm.  above  the  lower  border  of  the  bone. 

This  species  differs  from  the  living  T.  scrtpta  and  T.  elegans  in  the  form  of  the  nuchal  bone 
and  the  scutes  overlapping  it  and  in  having  had  no  notches  in  the  borders  of  the  carapace. 

The  nuchal  here  described  has  a  good  deal  of  resemblance  to  that  on  which  Pseiidcmys 
extincta  is  based.  The  latter  nuchal  is  that  of  a  considerably  larger  specimen  and  is  much 
smoother,  the  sculptural  ridges  having  much  less  elevation.  The  nuchal  scute,  too,  is  longer 
relatively  to  the  length  of  the  bone.  P.  concinna  has  narrower  nuchal  and  first  vertebral 
scutes.    The  same  is  true  of  P.  ruhrivenfris. 


358  FOSSII,    TURTLES    OF    NORTH    AMERICA. 

Genus  GRAPTEMYS  Agassiz. 

Shell  moderately  elevated,  with  dorsal  keel  more  or  less  strongly  developt.  Neural  plates 
hexagonal,  with  broad  ends  in  front.  Hinder  border  of  carapace  serrated.  Inguinal  buttresses 
rather  feeble,  articulated  to  the  fifth  costals.  Humero-pectoral  sulcus  crossing  behind  the 
entoplastron.  Plastron  with  a  median  notch  behind.  Alveolar  surfaces  of  the  upper  and  the 
lower  jaws  broad,  flat,  and  smooth.  Alveolar  plate  of  the  vomer  in  contact  with  the  palatines. 
Choanae  between  the  hinder  borders  of  the  orbits.  Symphysis  of  lower  jaw  long,  equal  to 
half  of  the  distance  between  the  quadrates. 

The  type  of  this  genus  is  G.  geographica,  the  geographic  terrapin  of  the  Mississippi 
Valley  (figs.  I,  2,  shell).  This  genus  is  distinguisht  from  Chrysemys,  Pseudemys,  and  Trach- 
emys  by  its  maxillary  and  dentary  alveolar  surfaces,  which  are  broad,  flat,  and  without  longitu- 
dinal ridges.  From  Malaclemys  it  differs  in  having  broader  alveolar  surfaces,  and  especially 
in  having  the  vomer  in  contact  with  the  palatines  on  the  alveolar  surfaces.  This  articulation 
and  the  broad,  flat  crushing-surfaces  of  the  jaws  remind  us  strongly  of  the  condition  found  m 
Lytoloma,  as  well  as  in  the  Toxochelyidae  and  the  Cheloniidae;  and  show  us  that  similar 
structures  may  arise  independently  in  different  groups.  The  evident  purpose  of  these  broad 
jaws  in  Graptemys  is  the  crushing  of  hard  food  substances.  G.  geographica  lives  habitually 
on  moUusks.     The  relations  of  the  palatines  and  the  vomer  need  further  study. 

There  can  be  little  doubt  that  Graptemys  has  been  derived  from  Malaclemys. 

Von  Reinach  described  (Abhandl.  Senckenb.  Gesellsch.,  xxviii,  1900,  p.  92,  plate  xxx, 
fig.  i)  a  new  genus  and  species  (Promalococlemmys  boulengert)  believed  to  be  closely  related 
to  Malaclemys.  There  can  be  hardly  a  doubt  that  what  is  represented  in  his  figure  as  the 
hinder  end  of  the  plastron  is  in  reality  the  anterior  end  of  another  specimen. 

Graptemys?  inornata  (Loomis). 
Figs.  455.  456- 
Chrysemys  inornata,  LooMis,  Amer.  Jour.  Sci.  (4),  xvni,  1904,  p.  429,  figs.  10,  II. 

This  species  is  based  on  a  nearly  complete  shell  which  was  discovered  by  Dr.  F.  B.  Loomis 
in  the  year  1903,  in  the  Titanotherium  beds  of  the  White  River  deposits,  in  Spring  Draw 
Basin,  10  miles  east  of  Creston,  Meade  County,  South  Dakota.  The  specimen  lay  beneath 
the  skull  of  a  titanothere;  but,  as  no  other  skeletal  parts  of  the  turtle  were  found,  the  shell 
had  probably  drifted  thither.  Through  the  liberality  of  Dr.  Loomis  I  have  been  enabled  to 
study  the  specimen. 

In  outline  the  shell  is  broadly  oval,  broadly  rounded  in  front,  and  rather  pointed  behind. 
The  elevation  of  the  shell  in  life  can  not  be  determined,  it  having  been  crusht  flat  during 

burial.  The  length  of  the  carapace  (fig.  455)  is  303  mm.; 
the  greatest  width,  253  mm.  Its  margin  is  slightly  excavated 
in  front,  with  shallow  notches  at  the  outer  ends  of  the  pos- 
terior marginal  sulci,  and  with  a  notch  in  the  border  of  the 
pygal.  There  appears  to  have  been  a  rounded  carina  on  the 
front  of  the  carapace,  and  this  reappears  near  the  rear. 

The  nuchal  bone  has  a  length  of  53  mm.  and  a  width 
of  66  mm.  The  eighth  neural  is  followed  by  2  suprapygals. 
The  accompanying  table  presents  the  dimensions  of  the 
median  bones  behind  the  nuchal. 

The  borders  of  the  carapace  in  front  of  and  behind  the 
bridges  are  acute  and  the  bones  are  thin.  The  second  per- 
ipheral bone  has  a  width  of  38  mm.  at  right  angles  to  the 
margin  of  the  shell;  the  ninth,  a  width  of  40  mm.  The  sulci 
between  the  marginal  and  the  costal  scutes  run  along  on  the  peripheral  bones  a  short  distance 
below  the  costo-peripheral  sutures,  except  in  front,  where  they  deviate  further  from  the  sutures. 
Posteriorly  the  sulcus  crosses  the  midline  on  the  rear  of  the  second  suprapygal.  The  nuchal 
scute  is  14  mm.  long  and  15  mm.  wide. 

The  vertebral  scutes  are  narrow.  Each  of  the  anterior  four  is  about  50  mm.  wide.  The 
fifth  has  an  extreme  width  of  70  mm. 


Element. 

Length. 

Width. 

Neural  i 

Neural  2 

Neural  3 

Neural  4 

Neural  5 

Neural  6 

Neural  7 

Neural  8 

Suprapygal  i.. 
:  Suprapygal  2 . . 
!  Pyeal 

27 
27 
28 
26 

24 
18 

15 
9 

25 
26 
26 

22 
22 
24 

23 
20 

27 
25 
18 
22 
53 
3' 

EMYDID^;. 


359 


The  total  length  ot  the  plastron  (fig.  456)  is  272  mm.;  but  along  the  midline,  from  the 
front  of  the  plastron  to  the  bottom  of  the  posterior  notch,  the  length  is  about  265  mm.  The 
anterior  lobe  has  a  length  of  about  85  mm.  and  a  width  of  140  mm.  At  the  suture  between  the 
epiplastrals  and  the  hyoplastra  the  width  is  122  mm.,  and  this  width  is  continued  backward 
about  22  mm.  further.  The  entoplastron  is  51  mm.  wide.  The  anterior  lip  projects  somewhat 
and  has  a  width  of  60  mm. 

The  posterior  lobe  has  a  width  of  134  mm.  and  a  total  length  of  90  mm.  Toward  the  hinder 
extremit)'  the  lobe  narrows  rather  rapidly  and  is  posteriorly  deeply  notcht.  The  humero- 
pectoral  sulcus  passes  behind  the  entoplastron.     The  gulars  extend  along  the  midline  for 


455- 


KiGS.  455  AND  456. — Grnptemys  inornnta.     Carapace  and  pla.stron  of  type.     X    about  \. 
455.  Carapace.  456.   Plastron. 

47  mm.;  the  humerals,  29  mm.;  the  pectorals,  30  mm.;  the  abdominals,  63  mm.;  the  femorals. 
53  mm.;  the  anais,  30  mm.    The  bridges  have  a  width  of  100  mm. 

The  present  species  is  here  referred  with  doubt  to  the  genus  Graptemys  Agassiz.  It  can 
hardly  belong  to  the  genus  Chrysemys  as  that  is  here  defined  and  the  type  of  which  is  C.  picta. 
The  shell  of  this  White  River  species  has  some  resemblance  to  that  of  Grnptem\s  geographica, 
having  a  low  rounded  dorsal  carina  and  an  elongated  first  suprapygal,  like  the  living  species 
just  named.  The  species  may  belong  to  either  Pseiidemys  or  Trachemys;  but  it  will  be  neces- 
sary to  have  the  skull  in  order  to  determine  its  relationships  with  certainty. 

Genus   TERRAPENE  Merrem. 

Shell  usually  short  and  broad,  rarely  elongated.  Neural  bones  hexagonal,  with  the  broader 
end  forward.  The  eighth  neural  usually  absent.  Plastron  as  broad  as  the  opening  of  the 
carapace,  composed  of  two  distinct  portions  movable  on  each  other  and  the  carapace,  there 
being  a  ligamentous  hinge  between  the  hyoplastra  and  the  hypoplastra  and  another  on  each 
side  between  the  bones  mentioned  and  the  carapace.  Zygomatic  arch  complete,  deficient,  or 
wanting.  Alveolar  surfaces  of  the  jaws  narrow  and  without  ridges.  Choanae  between  fronts 
of  orbits.    Digits  with  little  or  no  web.    Tail  short. 

Type:     Terrapene  Carolina  (Linn). 

The  known  members  of  this  genus  are  confined  to  North  America.  The  species  are 
closely  related,  and  their  number  is  not  certainly  determined.  On  the  number  of  the  digits 
of  the  hinder  feet  and  the  condition  of  the  zygomatic  arch  the  genus  has  been,  especially  by 


360 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


Cope,  split  into  a  number  of  genera.  The  type  of  Terrapene  is  T.  Carolina,  and  is  extremely 
variable.  Three  fossil  species  have  been  described  by  Cope — T .  eurypygia,  T.  marnochi,  and 
T.  angulllulata — but  the  latter  appears  to  be  identical  with  T.  eurypygia.  They  all  belong  to 
Pleistocene  deposits.  Another  species,  T.  putnami,  was  described  by  Hay  from  supposed 
Pliocene  of  Alifia  River,  Florida. 

The  shell  of  Terrapene  is  usually  nearly  as  broad  as  long,  but  that  of  T .  major  is  less  than 
three-fourths  as  broad  as  long.  It  is  sometimes  high  and  vaulted,  but  occasionally,  as  in  T. 
ornata,  it  is  rather  deprest. 

Nothing  is  known  regarding  the  origin  of  the  genus.  It  appears  not  improbable  that  it 
has  been  derived  from  Emys,  of  which  Emys  orbicularis  of  Europe  is  the  type.     Of  Emys  there 


Figs.  457  and  458. — Terrapene  ornata.     Xi-    Specimen  in  A.  M.  N.  H. 

457.   Carapace.  458.   Plastron. 

is  also  an  American  species,  E.  blandingi,  an  inhabitant  of  the  northern  United  States  and 
Canada  as  far  westward  as  Wisconsin.  In  Emys  there  is  a  transverse  hinge  between  the  hyo- 
plastrals  and  the  hypoplastrals,  less  perfect  than  in  Terrapene,  and  the  lobes  thus  formed  are 
somewhat  movable  on  the  carapace.  It  would  require  no  great  modifications  of  the  shell  and 
skull  of  Emys  to  transform  it  into  Terrapene.  Emys  is  found  in  Pleistocene  deposits  of  various 
parts  of  Europe,  and  it  is  probable  that  the  genus  had  its  origin  there,  and  that  it  migrated 
thence  to  North  America.    Doubtless,  Terrapene  was  developt  in  North  America. 

Fig.  457  is  a  representation  of  the  carapace  of  Terrapene  ornata;  while  fig.  458  represents 
the  plastron.     The  species  now  inhabits  Kansas. 

Key  to  Fossil  Species  of  Terrapene. 

A^.  Plastron  very  thick,  the  thickness  of  the  hypoplastron  being  nearly  one-third  its  length.  .  putnami 
A^.   Plastron  much  thinner. 

n'.   Plastron  with  flat  hinder  lobe,  its  free  border  emarginated  at  end  of  femoro-anal  sulcus. 

Middle  of  back  flat  transversely marnochi 

a^.   Plastron  with  hinder  lobe  convex,  the  free  border  not  emarginate.     Middle  of  back 

concave  transversely    canaliculata 

a'.  Closely  related  to  T.  Carolina.    Vertebral  scutes  wide,  the  fifth  in  contact  with  the 

tenth  marginal eurypygia 

Terrapene  putnami  Hay. 

Plate  56,  figs.  7,  8;   text-figs.  459-462. 

Terrapene  putnami.  Hay,  Bull.  Amer.  Mas.  Nat.  Hist.,  xxii,  1906,  p.  30,  figs.  4-7. 

The  present  species  is  based  on  a  single  hypoplastral  bone  which  was  placed  by  Professor 
F.  W.  Putnam,  then  of  the  American  Museum  of  Natural  History,  in  the  hands  of  the  writer 


emydida;. 


361 


for  examination.  This  and  some  other  bones  were  dredged  by  him  in  the  Alifia  River,  Florida, 
about  a  mile  above  its  entrance  into  Tampa  Bay.  With  this  bone  there  were  obtained  remains 
of  some  species  of  Trachemys  and  a  peripheral  of  a  very  large  Testudo,  possibly  T.  crassi- 
scutata  (Leidy).  The  writer  has  been  informed  that  these  bones  were  accompanied  by  bones 
of  horses,  tapirs,  etc.  The  remains  seem  therefore  to  agree  with  those  taken  from  the  Peace 
Creek  beds,  near  Arcadia,  DeSoto  County,  of  the  same  state.  The  latter  bone  bed  has  been 
declared  to  be  of  older  Pliocene  age,  but  the  evidence  appears  to  be  contradictory. 

This  new  species  of  box-tortoise  is  remarkable  for  its  size  and  the  great  thickness  of  its 
plastron.  The  length  of  the  left  hypoplastron  (plate  56,  fig.  7),'measured  along  the  midline,  is 
73  mm.,  and  the  width  is  almost  exactly  the  same.    If  this  bone  had  the  same  ratio  to  the  other 


459- 


460. 


KiG.  459  AND  460. — Terraperie  putnami.     Hypoplastron  of  type.     X  S- 

459.  Section  from  articulation  with  opposite  hypoplastron  (on  right)  to  lateral  hinge  (on  left). 

460.  Face  articulating  with  its  fellow.    Anterior  end  of  the  bone  at  right  hand. 

portions  of  the  shell  that  the  corresponding  bone  has  in  T.  Carolina,  the  carapace  must  have 
been  265  mm.  long,  and  the  width  about  200  mm. 

At  the  midline  of  the  plastron,  just  in  front  of  the  union  of  the  hypoplastron  with  the 
xiphiplastron  (fig.  460,  on  the  left),  the  former  bone  is  22.5  mm.  thick.  In  a  specimen  of  T. 
Carolina  whose  hypoplastron  is  38  mm.  wide  the  thickness  at  the  point  named  is  4  mm.  or  less. 
In  the  fossil  the  thickness  becomes  reduced  laterally,  so  that  at  two-fifths  the  distance  toward 
the  lateral  hinge  (fig.  459)  it  is  only  12  mm.  It  then  increases  and  at  the  hinge  is  15  mm. 
Toward  the  anterior  end  of  the  bone  the  thickness  diminishes  to  12  mm. 

The  hinder  portion  of  the  lateral  hinge  (plate  56,  fig.  8)  is  broken  away.  At  its  anterior 
end  there  is  a  deep  and  rough  pit  for  a  process  proceeding  from  the  fourth  and  fifth  peripherals, 


462. 


Pigs.  461  AND  462. — Terrapene  putnami? .     Fragments  of  carapace.    X  5. 
Specimen  in  Vanderbilt  University. 

461.  Left  side  of  front  of  carapace,     c.  p.  i,  part  of  first  costal  plate;    m.  s.  l,  m.  i.  3,  m.  j.  4,  second,  third,  and 

fourth  marginal  scutes. 

462.  Rear  of  carapace,     m.s.  11,  m.  j.  12,  eleventh  and  twelfth  marginal  scutes;   per.  1 1,  eleventh  peripheral;  pv, 

pygal;  spy,  suprapygal. 

as  in  T.  Carolina.  The  hinder  border  of  this  pit  is  about  22  mm.  behind  the  anterior  border  of 
the  bone.  Behind  this  comes  the  flat,  rough,  and  perpendicular  surface,  about  14  mm.  high, 
that  articulated  loosely  with  the  fifth  and  sixth  peripherals,  forming  one  side  of  the  lateral 
hinge.  This  surface  is  relatively  broader  and  flatter  than  in  T.  Carolina  and  resembles  more 
that  found  in  T.  ornata.  It  is  likewise  broader  and  flatter  than  the  same  surface  in  T.  mar- 
nochi,  judging  from  the  carapace  in  the  American  Museum  of  Natural  History  so  identified. 
In  that  specimen  the  hinge  surface  on  the  carapace  is  only  8  mm.  wide. 

The  hyohypoplastral  hinge  hardly  differs  from  that  of  T.  Carolina,  except  in  thickness, 
which  in  T.  putnami  is  close  to  12  mm.    The  upper  half  of  the  hinge  (fig.  460)  is  rough  for  the 


362  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

attachment  of  the  ligament.  Near  the  outer  end  of  this  hinge  nearly  the  whole  surface  is  rough. 
The  lower  half  of  the  anterior  face  projects  in  front  of  the  upper  half  and  is  mostly  smooth 
and  was  covered  with  the  horny  epidermis. 

On  the  lower  surface  of  the  bone  is  seen  the  abdomino-femoral  sulcus.  The  abdominal 
scutes  were,  in  fore-and-aft  extent,  33  mm.  laterally  and  55  mm.  at  the  midline.  On  this  surface 
are  some  faint  grooves  produced  by  the  growth  of  the  scutes.  Two  of  these  grooves  near  the 
anterior  border  are  especially  conspicuous.  This  species  is  dedicated  to  Prof.  Frederick  W. 
Putnam,  the  distinguisht  archeologist  and  ethnologist. 

In  a  considerable  collection  of  fossil  turtle  bones  sent  to  him  from  Vanderbilt  University, 
Nashville,  Tennessee,  the  writer  finds  2  fragments  of  the  carapace  of  a  large  box-tortoise. 
This  collection  was  obtained  in  Hillsboro  County,  Florida,  by  Dr.  W.  H.  Jarman  and  belongs 
to  the  university  named  above.    The  fragments  probably  belong  to  7 .  putriamt. 

One  portion  (fig.  461)  consists  of  the  areas  occupied  by  the  second,  third,  and  a  part  of 
the  fourth  left  marginal  scutes  and  a  portion  of  the  contiguous  first  costal.  This  fragment, 
compared  with  the  carapace  here  referred  to  Cope's  T .  tnamochi,  indicates  a  carapace  about 
320  mm.  long.  I'he  bones  are  solidly  co-ossified  and  the  sutures  obliterated,  showing  that  the 
individual  was  aged.  Where  the  suture  between  the  first  and  second  peripherals  should  occur 
the  bone  is  14  mm.  thick.  The  free  edge  is  acute.  In  the  area  covered  by  the  fourth  marginal 
the  border  is  revolute.  The  second  and  the  third  marginals  measure  each  33  mm.  along  the 
free  border  and  are  about  20  mm.  high. 

In  the  same  lot  of  bones  is  a  fragment  (fig.  462)  furnishing  the  suprapygal,  the  pygal,  and 
the  right  and  left  eleventh  peripherals.  The  bones  are  co-ossified,  but  the  sutures  may  be 
traced.  The  individual  probably  had  a  length  of  about  250  mm.  The  free  edge  is  acute  and 
somewhat  recurved.  The  eleventh  peripheral  is  10  mm.  thick.  The  fifth  vertebral  scute  is 
50  mm.  wide,  while  that  of  the  carapace  of  T .  tnamochi  is  40  mm.  wide.  The  two  twelfth 
marginals  taken  together  measure  40  mm.;  those  of  T.  marnochi,  37  mm.;  the  height  of  the 
scutes  in  the  two  species  is  the  same,  13  mm.  The  height  of  the  eleventh  marginal  is  28  mm.; 
that  of  T .  marnochi,  only  32  mm.  It  is  evident  that  the  Florida  specimen  does  not  belong  to 
T.  marnochi. 

Terrapene  marnochi  (Cope). 
Plate  58,  figs.  1,2. 

Cistudo  marnochii,  CoPE,  Free.  Amer.  Phiios.  See,  xvii,  1878,  p.  229;  Amer.  Naturalist,  xxiii,  1889, 

p.  161,  Feb. 
Cistudo  marnochii,  Cope,  Amer.  Naturalist,  xix,  1885,  p. 1208. 
Terrapene  marnochii.  Hay,  Bibliog.  and  Cat.  Koss.  Vert.  N.  A.,  1902,  p.  449. 

This  species  was  founded  on  the  posterior  lobe  of  an  individual  which  was  discovered  by 
Gabriel  W.  Marnock,  in  the  Equus  beds  of  Atascosa  County,  Texas.  What  has  become  of  the 
specimen  is  not  known.  It  does  not  appear  to  be  in  the  Cope  collection  of  fossil  reptiles  in  the 
American  Museum  of  Natural  History  at  New  York.  The  specimen  was  not  figured  by  Cope. 
The  following  is  his  description  of  the  type: 

Represented  by  the  posterior  lobe  of  the  plastron  of  an  individual  of  twice  the  bulk  of  the  exist- 
ing North  American  Cistudos.  It  is  broadly  rounded  posteriorly,  and  there  is  an  emargination  at  the 
femoro-anal  dermal  suture.  The  anterior  suture  is  straight,  as  is  also  the  lateral,  which  measures 
more  than  a  third  the  length  of  the  entire  lobe.  On  the  upper  side  of  the  angle  included  by  these 
sutures  is  the  fossa  for  fixed  attachment  with  the  carapace.  The  beveled  face  of  the  fore  edge  of  the 
lobe  is  quite  wide.  The  dermal  sutures  are  well  marked.  The  anal  scuta  are  large,  their  median 
length  being  half  that  of  the  lobe.  The  common  femoral  suture  is  only  half  as  long  as  the  ventral. 
The  inferior  surface  is  nearly  flat  in  every  direction,  and  the  surface  is  smooth.  The  posterior 
border  of  the  specimen  is  broken  away. 

This  species  was  obtained  from  the  same  formation  as  the  la.st,  by  Gabriel  W.  Marnock,  to 
whom  I  dedicate  it. 

In  the  American  Museum  there  is  a  large  carapace  (plate  58,  figs,  i ,  2)  of  a  species  of  this 
genus  which  was  found  in  the  Cope  collection  of  fossil  reptiles,  but  which  appears  never  to 
have  been  mentioned  by  Professor  Cope.  Accompanying  it  is  a  label  stating  that  it  was 
found  in  the  "Elephant  beds,"  on  San  Diego  Creek,  Texas,  and  had  been  sent  by  Mr.  William 


EMYDID^. 


363 


Taylor.  We  learn  from  the  American  Naturalist  (vol.  xix,  1885,  p.  1208)  that  this  gentleman 
had  collected  materials  for  Professor  Cope  in  the  Equus  beds,  in  the  region  about  San  Diego. 
This  locality  is  about  80  miles  south  of  that  which  furnisht  the  type  of  T.  marnochi. 

The  catalog  number  of  the  San  Diego  specimen  is  3936.  The  matrix  was  a  mixture  of 
gravel  and  sand. 

It  is  assumed  for  the  present  that  the  specimen  referred  to  belongs  toT .  marnochi.  The  type 
is  spoken  of  as  being  large.  Unfortunately  Professor  Cope  gave  no  measurements.  The  length 
of  the  carapace  of  the  San  Diego  specimen  is  215  mm.;  the  breadth  is  141  mm.  The  width 
is  therefore  two-thirds  the  length,  indicating  an  elongated  form.  T .  ornata,  of  Kansas,  is 
nearly  as  wide  as  long.  T.  major,  of  Louisiana,  is  relatively  elongated,  but  even  here  the 
width  is  three-fourths  of  the  length.  The  outline  of  the  carapace  is  like  that  of  T.  major,  the 
hinder  portion  being  only  slightly  wider  than  the  middle.  The  width  at  the  line  of  the  hinge 
is  137  mm.;  at  the  seventh  peripherals,  147  mm.  The  height  is  95  mm.,  two-thirds  the  width. 
The  middle  of  the  back  is  rather  flat.  There  are  traces  of  a  dorsal  keel  anteriorly,  and  these 
traces  are  better  defined  on  the  area  of  the  third  vertebral  scute,  and  are  yet  perceptible  on  the 
fourth.  On  each  side  of  this  keel,  on  the  third  and  fourth  vertebral  scutes,  there  is  a  distinct 
broad,  but  shallow,  channel.     Most  of  the  area  of  the  fifth  scute  is  concave. 

The  margins  of  the  carapace  are  little  flared  upward,  far 

less  than  those  of  T.  major.    A  distinct  keel  runs  along  each 

side,  joining  the  anterior  free  border  of  the  carapace  with  the 

hinder  free  border. 

The  individual  was  an  aged  one,  and  the  sutures  between 

the  bones  are  completely  obliterated. 

The  sulci  are  everywhere  deeply  imprest.     The  vertebral 

scutes  are  unusually  narrow.     The  table  herewith  presents  the 

dimensions  of  these  scutes.     The  lengths  are  taken  along  the 

midline;  the  widths  are  the  maximum. 
The  anterior  end  of  the  first  vertebral  projects  forward  between  the  first  pair  of  marginals. 
Similarly  the  anterior  ends  of  the  third  and  fourth  vertebrals  project  forward  each  into  the 
hinder  border  of  the  scute  in  front.  The  marginal  scutes  are  large.  The  first  rises  22  mm. 
from  the  free  border,  the  sixth  23  mm.  above  the  lateral  keel,  and  the  ninth  27  mm.  above  the 
free  border. 


Scute. 

Length. 

Width. 

5° 

3*        ! 

47 

4'          1 

49 

46 

48 

4i 

36 

39 

464.  464a.  4651'. 

Figs.  46^-465. — Terrapenc  canaliculata.     Portions  of  the  type.     X  §. 

463.  Fourth  right  peripheral,  with  sections  of  the  ends    («,  anterior;   h,  posterior). 

464.  Region  of  seventh  and  eighth  marginal  scutes,  with  section  (a). 

465.  Enloplastron  and  section  (ta)  of  border  of  hinder  lobe. 


Terrapene  canaliculata  Hay. 

Figs.  463-465. 

Terrapene  canaliculata,  Hay,  Bull.  Amer.  Mu.s.  Nat.  Hist.,  xxiii,  1907,  p.  850,  figs.  5-7. 

The  fragmentary  remains  that  testify  to  the  former  existence  of  this  species  belong  to  the 
U.  S.  National  Museum,  having  been  sent  there  many  years  ago  by  Dr.  J.  P.  Scriver.  They 
had  been  found  on  either  Whitemarsh  or  Skedaway  Island,  below  Savannah,  Georgia.    The 


364  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

exact  age  of  the  deposits  is  not  known,  but  they  belong  probably  either  to  the  late  Pliocene 
or  to  the  Pleistocene. 

The  individual  was  of  larger  size  than  any  belonging  to  any  existing  species.  The  right 
fourth  peripheral  (fig.  463)  has  a  length  of  26  mm.,  from  which  we  may  infer  that  the  carapace 
had  a  length  of  about  220  mm.  The  anterior  end  of  this  peripheral  has  a  thickness  of  8  mm.; 
the  hinder  end  a  thickness  of  19  mm.  On  the  outer  surface  is  a  sharp  longitudinal  keel,  which 
ran  from  the  free  border  of  the  anterior  peripherals  to  that  of  the  posterior  peripherals.  This 
keel  borders  outwardly  a  broad  gutter-like  groove.  Fig.  464  shows  the  region  of  the  seventh  and 
eighth  marginal  scutes,  with  a  section  across  the  seventh.  Portions  of  the  second  and  third  cos- 
tal scutes  are  presented.  The  thickness  of  the  costals  varies  from  4  mm.  to  6  mm.  A  frag- 
ment of  the  dorsal  region  shows  that  the  midline  of  the  carapace  was  concave  transversely. 

The  lateral  hinge-line  appears  to  have  had  a  length  of  about  70  mm.  Its  thickness  is  10 
mm.  The  entoplastron  (fig.  465)  is  subcircular  in  outline.  It  varies  in  thickness  from  5  mm. 
to  7  mm.    The  border  of  the  hinder  lobe,  at  the  hypoxiphiplastral  suture,  is  15.5  mm. 

Terrapene  eurypygia  (Cope). 
Figs.  466-470. 

Cistudo  eurypygia,  CoPE,  Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1869,  p.  124. 

Terrapene  eurypygia,  Hay,  Proc.  Acad.  Nat.  Sci.  Phila.  1902,  p.  385,  figs.  6,  7;   Bibliog.  and  Cat.  Foss 
Vert.  N.  A.,  1902,  p.  449;  Maryland  Geol.  Surv.,  Pliocene  and  Pleistocene,  1896,  p.  169,  pi.  xi,  fig.  2. 

The  present  species  has  as  its  type  a  fragment  of  the  hinder  portion  of  the  carapace  which 
was  discovered  by  Dr.  Samuel  Harrison,  on  Oxford  Neck,  Talbot  County,  Maryland,  in 
Pleistocene  deposits,  associated  with  remains  of  Elephas  primigenius,  Cervus  canadensis, 
Odocotleus  virgtnianus,  and  Chelydra  serpentina.  This  type  is  now  in  the  American  Museum 
at  New  York  and  bears  the  catalog  number  1484.    It  is  here  represented  by  fig.  466. 

Cope's  type  presents  a  portion  of  the  right  seventh  costal  plate,  portions  of  the  costals  of  the 
eighth  pair,  the  suprapygal,  the  pygal,  and  the  tenth  and  eleventh  peripherals.  Those  charac- 
ters which  in  this  type  appear  to  distinguish  the  species  from  T.  Carolina  are  the  greater  breadth 
of  the  fifth  vertebral  scute  and  the  union  of  this  vertebral  with  the  tenth  marginal  scute.  It  is 
proper  to  remark  here  that  the  present  writer,  in  his  description  of  this  species  in  the  Pro- 
ceedings of  the  Philadelphia  Academy,  called  the  tenth  marginal  the  ninth. 

An  estimate  makes  it  probable  that  the  individual  to  which  the  type  fragment  belonged 
had  a  length  of  carapace  equal  to  about  140  mm.  The  fifth  vertebral  scute  had  a  width  of  40 
mm.  The  width  of  this  vertebral  in  T .  Carolina  is  variable,  but  out  of  6  individuals  observed, 
only  I,  with  shell  130  mm.  long,  had  this  scute  as  much  as  39  mm.  wide.  In  T.  eurypygia 
the  fifth  vertebral  joins  the  tenth  marginal  scute  by  a  sulcus  4.5  mm.  long.  Usually  in  T. 
Carolina  these  two  scutes  fail  to  reach  each  other  by  some  millimeters.  As  stated  by  the  author 
elsewhere,  an  examination  of  eighteen  specimens  of  T .  Carolina  showed  that  in  only  one  the 
fifth  vertebral  was  in  contact  with  the  tenth  marginal  on  both  sides,  while  in  another  these 
scutes  were  in  contact  on  only  one  side  of  the  carapace.  Relying  on  the  type  alone  we  might 
conclude  that  possibly  T .  eurypygia  is  only  an  individual  variation  of  T .  Carolina. 

In  1899  (Jour.  Phila.  Acad.,  xi,  pp.  193-267)  Professor  Cope  described  various  remains 
of  the  vertebrates  which  had  been  collected  by  Messrs.  Dixon  and  Mercer  in  the  Port  Kennedy 
cave.  Among  other  things  there  were  three  tortoises  found,  viz. :  Clemrnys  insculpta,  C.  per- 
crassa,  and  T'oxaspis  (Terrapene)  anguillulata.  There  belonged  to  the  collection,  however, 
another  box-tortoise  which  was  not  mentioned  by  Cope,  and  was  perhaps  not  seen  by  him. 
These  remains  consist  of  almost  the  whole  of  the  plastron  and  of  various  fragments  of  the 
carapace  and  the  right  humerus. 

An  examination  of  these  bones  showed  that  they  belonged  either  to  Terrapene  Carolina  or 
to  a  species  closely  related  to  it.  It  was  soon  observed  that  the  tenth,  or  antepenultimate, 
marginal  scute  comes  into  contact  with  the  last  vertebral  (fig.  467a),  a  condition  which  recalled 
Cope's  Cistudo  eurypygia,  and  a  close  comparison  proved  that  they  are  identical,  one  of  the 
portions  of  the  Port  Kennedy  specimen  being  fortunately  the  right  margin  ot  the  rear  of  the 
shell  from  near  the  midline  to  the  hinge.  The  question  therefore  arises  whether  or  not  the  new 
material  confirms  Cope's  view  of  the  distinctness  of  the  species. 


EMYDID^.. 


365 


The  unusual  width  of  the  fourth  and  fifth  vertebral  scutes  is  proved  by  Cope's  type  and 
confirmed  by  the  Port  Kennedy  specimen.  Belonging  to  the  latter  is  a  fragment  of  the  cara- 
pace presenting  a  part  of  the  nuchal,  a  part  of  the  first  and  second  costals  and  the  first  and 
second  peripherals  (fig.  467^).  In  T.  Carolina  the  first  vertebral  does  not  usually  encroach  on 
the  first  peripheral  bone;  in  the  fragment  alluded  to  above,  the  vertebral  reaches  over  on  the 
first  peripheral  nearly  to  the  sulcus  between  the  first  and  second  marginals.  The  anterior 
vertebral  must  have  been  34  mm.  wide,  about  6  mm.  wider  than  in  a  specimen  of  T.  Carolina 
at  hand.  We  must  conclude  that  the  other  vertebrals  were  wider  than  they  commonly  are  in 
T.  Carolina.  An  estimate  makes  it  probable  that  the  fourth  vertebral  in  T.  euryp\gia,  type,  was 
about  42  mm.  wide. 

Fig.  467a  presents  a  view  of  the  fragment  of  the  rear  of  the  carapace  of  the  Fort  Kennedy 
specimen,  the  interrupted  lines  having  been  added  in  order  to  show  the  position  of  the  frag- 
ment. The  crossing  of  the  sulci  on  the  upper  portion  of  the  drawing  indicates  the  presence  of 
a  small  scute  cut  off  from  the  fifth  vertebral,  a  slight  abnormality.    In  fig.  ^bja  the  peripherals 


467a. 
Figs.  466  and  467. — Terrapene  curypygia.      X  I. 


467*. 
Portions  of  Carapace. 

.  12,  eleventh  and  twclftli 


466.  Rear  of  carapace  of  type.    c.p.  7,  c.  p.  8,  seventh  and  eighth  costals;  m.  j.  11,  m. 

marginal  scutes;    per.  10,  per.  11,  peripherals;   py,  pygal;    spy^  suprapygal. 
467a.  Rear  of  carapace,    c.p.  8,  eighth  costal  plate;   per.^,  per.  lo,  per.  11,  ninth  to  eleventh  peripherals;   m.  s.  9, 

m.  s.  10,  m.  s.  II,  m.  J.  12,  ninth  to  twelfth  marginal  scutes;  py,  pygal;  spy,  suprapvj;al.    The  letters  tn.  j. 

of  ninth  marginal  lie  partly  on  tenth  marginal. 
4676.  Front  of  carapace,    c.  p.  i,  first  costal  bone;  nu.  p.,  nuchal  bone. 

and  marginals  are  indicated.  The  tenth  scute  is  the  one  lying  partly  on  the  ninth  peripheral 
and  partly  on  the  tenth.  In  both  figures  the  bony  sutures  are  represented  bv  zigzag  lines, 
while  the  sulci  between  the  scutes  are  shown  by  dotted  lines. 

The  plastron  of  the  Port  Kennedy  specimen  is  131  mm.  long.  In  general  it  resembles  that 
of  T.  Carolina.  The  width  of  the  hinder  lobe  is  79  mm.;  the  length  was  almost  exactly  the 
same.  In  the  case  of  6  specimens  of  T.  Carolina  examined  the  width  of  this  lobe  is  from  4  to 
6  mm.  wider  than  long;  in  one  individual  the  width  is  2  mm.  less  than  the  length.  The  form 
and  dimensions  of  the  scutes  of  the  plastron  are  essentially  as  they  are  in  T.  Carolina. 

A  study  of  the  plastron  of  the  Port  Kennedy  specimen  makes  it  evident  that  this  portion  of 
the  shell  was  almost  everywhere  thicker  than  in  the  corresponding  parts  of  T.  Carolina.  Nearly 
the  whole  of  the  border  of  the  anterior  lobe  is  thicker  and  with  a  more  rounded  edge.  The 
hypoplastron  of  T.  Carolina  at  the  hinge  is  3  mm.  thick;  that  of  T.  eurypygia,  4  mm.  The 
sloping,  scute-covered  border  of  the  hinder  lobe,  at  the  union  of  hypoplastron  and  xiphiplas- 
tron,  is  in  T.  Carolina  5  mm.  thick;  in  T.  eurypygia,  7  mm.  thick.  This  border  is  also  wider 
in  the  latter  species  than  in  any  specimens  of  the  living  species  at  hand. 

Fig.  468  represents  the  plastron  of  the  specimen  described  above  from  the  Port  Kennedy 
cave.     It  resembles  that  ot  T.  Carolina  but  appears  to  be  relatively  more  elongated. 


366 


l-OSSll.    TURTLKS    OF    NORTH    AMERICA. 


Professor  Cope  in  1899  (Jour.  Phila.  Acad.,  xi,  p.  196,  plate  xix,  fig.  i)  described  and 
figured  a  box-tortoise  which  he  called  Toxaspts  anguillulafus.  Of  this  tortoise  he  had  at  com- 
mand five  fragmentary  carapaces  on  beds  of  matrix,  three  parts  of  plastrons,  and  two  moulds 
of  carapaces.    All  these  had  been  obtained  in  the  cave  near  Port  Kennedy. 

The  type  of  Cope's  Toxaspts  anguillulatus  is  number  155  of  the  collection  of  the  Philadel- 
phia Academy.  This  is  figured  as  cited  in  the  synonymy  at  the  head  of  this  article;  but  the 
figure  is  poorly  printed  and  does  not  well  show  the  structure.     A  diagram  of  the  specimen 

(fig.  469)  is  here  presented;  but  even  in  the  specimen  some 
sutures  are  obscure  and  on  the  left  side  the  hinder  peripherals 
have  been  somewhat  displaced. 

Professor  Cope  did  not  compare  his  species  with  the  one 
which  he  had  described  in  1869.  The  present  writer,  having 
examined  Cope's  types  of  both  species,  concludes  that  they  are 
identical.  Cope  stated  that  his  type  carapace,  No.  155,  is  of 
larger  size  than  that  of  any  of  the  existing  species  of  what  he 
called  the  Terrapenidae.  However,  a  comparison  with  a  shell 
of  T.  Carolina  shows  that  the  carapace  was  not  more  than  140 
mm.  long,  perhaps  not  more  than  130  mm.;  and  occasional 
individuals  of  T .  Carolina  attain  that  size,  while  some  of  T . 
major  become  still  larger.  Cope  believed  that  his  T.  anguil- 
lulafus had  a  more  deprest  shell  than  any  of  the  living  species,  but  this  may  be  doubted. 

Another  of  Cope's  specimens  is  numbered  154.  This  (fig.  470)  furnishes  the  three  anterior 
neurals.    Their  measurements  are  given  in  the  table  above. 


Neural . 

Length. 

Width. 

Fig.  469: 

3 

16 

>7 

4 

14 

17 

s 

'4 

17 

6 

9 

>S 

7 

>3 

12 

Fig.  470: 

I 

16 

'3 

2 

>3 

16 

3 

»5 

•7 

468. 


470/-. 


469. 


KlGS.  468-470. — Terrapene  eurypygta.     Portions  of  shells.      Xj. 

468.  Plastron. 

469.  Rear  of  carapace  of  type  of  Toxaspts  anguillulatus. 
470a.  Front  of  carapace.     No.  154  Phila.  Acad. 

470^.  Portion  of  hypoplastra  and  liphiplastra.     No.  154  Phila.  Acad. 

From  the  measurements  of  No.  155  (fig.  469),  given  in  the  table  above,  it  will  be 
seen  that  all  the  neurals,  except  the  first  and  the  last,  have  the  width  considerably  greater  than 
the  length.    They  appear  to  be  somewhat  broader  than  those  of  7".  Carolina. 

The  eighth  neural  was  not  developt.  The  seventh  is  not  as  long  as  the  width  of  the  seventh 
costals;  and,  as  a  result  of  these  conditions,  the  seventh  costals  meet  on  the  midline  behind  the 
seventh  neural  and  the  eighth  costals  join  by  their  whole  proximal  width.  In  some  specimens 
oi  T.  Carolina  there  is  a  long  and  narrow  eighth  neural. 


liMYDlD^.  367 

In  the  type  of  T .  anguiUulatus,  as  shown  in  the  figure  (fig.  469),  the  hinder  peripherals  on 
the  left  have  been  pushed  forward  over  the  ends  of  the  costals. 

The  suprapygal  is  1 1  mm.  high  and  25  mm.  long.    The  eighth  peripheral  is  5.5  mm.  thick. 

From  No.  154  we  learn  that  the  first  vertebral  scute  was  38  mm.  wide  and  the  second 
40  mm.  From  No.  155  it  is  seen  that  the  second  and  third  were  each  44  mm.  wide;  the  fourth, 
42  mm.;  and  the  fifth,  40  mm.  What  is  ot  special  interest  is  that  in  No.  155  the  tenth  marginal 
scute  comes  into  contact  with  the  outer  extremity  of  the  fifth  vertebral  scute.  This  is  the 
character  on  which  T.  eurypygia  was  based.  A  fragment  of  the  plastron  of  No.  154  of  the 
Philadelphia  Academy  shows  that  the  femoro-anal  sulcus  extends  forward  to  the  hypoxiphi- 
plastral  suture.  Cope  states  that  this  character  had  not  been  observed  by  him  in  any  other 
species  of  the  family.    It  is,  however,  occasionally  seen  in  T .  Carolina. 

Cope  describes  a  peculiar  and  fine  sculpture  as  present  on  the  type  of  his  'Toxaspis  anguil- 
lulatus.  This  is  a  well-markt  vermiculation.  At  the  borders  of  the  costals  the  ridges  place 
themselves  at  right  angles  with  the  sutures.  A  similar  vermiculation  is  seen  in  the  type  of  7". 
eurypygia,  but  no  modification  of  it  is  seen  where  the  seventh  costal  joins  the  eighth. 

Family  TESTUDINID.ff;  Gray. 

Cryptodira  having  most  of  the  characters  of  the  Emydidae,  but  modified  for  a  more  strictly 
terrestrial  life.  Size  medium  to  very  large.  Jaws  fitted  for  a  vegetable  diet.  Palate  vaulted. 
Zygomatic  and  postorbital  arches  present;  the  temporal  roof  not  otherwise  represented. 
Stapedial  notch  closed.  Neck  retractile  within  the  shell.  Plastron  suturally  united  with  the 
carapace,  with  the  buttresses  rarely  ascending  within  the  carapace.  The  bridge  broad.  Neural 
bones  sometimes  mostly  hexagonal;  but  often,  especially  in  Testudo,  octagonal  ones  alternating 
with  tetragonal.  Penultimate  suprapygal  usually  bifurcate,  with  its  limbs  resting  on  the  hinder 
peripherals  and  enclosing  the  hindermost  suprapygal.  Plastral  bones  nine.  The  epiplastrals 
usually  thickened  and  projecting  as  a  lip.  The  procoracoid  process  forming  with  the  body  of 
the  scapula  more  than  a  right  angle.  Coracoids  greatly  expanded  at  the  median  border. 
Humerus  with  the  radial  and  ulnar  processes  approximated  on  the  ventral  side.  Digits  short, 
without  rudiment  of  web.  Phalanges  not  more  than  2  in  any  digit;  all  shortened;  anterior 
claws  usually  5,  sometimes  only  4;  hinder  claws  4.  Sulcus  between  the  costal  and  the  marginal 
scutes  usually  coinciding  with  the  sutures  between  the  costal  and  peripheral  bones. 

The  present  family  is  here  regarded  as  including  5  living  genera — Testudo,  Gopherus, 
Kinyxts,  Pyxis,  and  Homopus.  It  seems  not  improbable  that  a  more  accurate  study  of 
the  skeletons  of  living  tortoises  would  result  in  the  establishment  of  additional  genera.  Kinyxis 
is  confined  to  tropical  Africa,  Pyxis  to  Madagascar,  and  Homopus  to  southern  and  western 
Africa.  Testudo  is  represented  in  the  present  fauna,  or  has  been  within  historical  times,  by 
more  than  forty  species,  and  these  belong  to  South  America,  the  Galapagos  Islands,  Europe, 
Asia,  Africa,  Madagascar,  and  the  Aldabra,  Maritius,  Seychelles,  Comoro,  and  Rodriguez 
Islands.  Gopherus  (Xerobates)  includes  the  Testudinidae  of  North  America,  altogether  3 
species. 

The  extinct  genera  belonging  to  this  family  are  Hadrianus,  Achilemys,  and  Stylemys. 
Besides  the  extinct  species  referred  to  the  genera  just  named,  a  few  belong  to  Homopus  and 
many  to  Testudo. 

Extinct  species  of  Testudo  are  known  with  certainty  from  the  Lower  Oligocene  to  the 
deposits  of  the  recent  period.  A  very  large  species,  T .  atlas,  is  known  from  the  Pliocene  of  the 
Siwalik  Hills,  India.  Its  shell  reached  a  length  of  6  feet.  Other  Pliocene  species  have  been 
described  from  Europe,  among  them  T .  perptniana,  from  France.  Various  species  are  known 
from  the  Miocene  of  Europe,  among  them  T .  leberonis,  from  Mount  Leberon,  France.  T . 
gigas  is  known  from  a  nearly  complete  specimen  and  T .  eurysternum  from  fragments,  both  from 
the  Upper  Oligocene  of  France.  A  specifically  unnamed  specimen  of  the  genus  is  noticed  by 
Lydekker  (Cat.  Foss.  Rept.,  Brit.  Mus.,  iii,  p.  91)  as  being  represented  by  an  anterior  periph- 
eral from  the  Lower  Oligocene  of  France.  As  remarkt  by  Lydekker  (op.  cit.,  p.  72)  there 
is  no  known  reason  why  some  of  the  Lower  Tertiary  species  described  under  the  name 
Testudo  may  not  belong  in  reality  to  Hadrianus.  Zittel  states  that  the  oldest  known  land- 
tortoise  in  Europe  is  T .  lamanoni  Gray,  from  the  Oligocene  gypsmergel  of  Aix,  in  Provence. 


368 


KOSSIL    TURTLES    OF    NORTH    AMERICA. 


This  formation  is  placed  by  Lapparent  at  the  base  of  the  Ohgocene.  The  specimen  is  a  very 
imperfect  one,  and  it  may  be  said  that  the  genus  is  only  approximately  determinable.  Dr. 
A.  E.  Andrews  (Surv.  Dept.,  Pub.  Works  Ministry,  Geol.  Surv.  Egypt,  1903;  Catalogue  Tert. 
Vert.  Fayum,  Egypt,  1906,  p.  278,  plate  xxiv)  has  described  a  land-tortoise  from  the  Upper 
Eocene  of  Egypt  to  which  he  has  given  the  name  Testudo  ammon.  If  a  true  Testudo,  it  is  the 
oldest  known.  The  publisht  figures  show  that  the  neurals  are  variable  in  form,  but  the  relation- 
ships to  typical  Testudo  are  so  close  that  it  may  be  accepted  as  belonging  to  this  genus.  In 
some  respects  it  appears  to  be  intermediate  between  Testudo  and  Hadrianus. 

The  oldest  known  representative  of  the  family  is  Hadrianus  majusculus,  of  the  Wasatch 
beds  of  New  Mexico. 

The  following  table  presents  a  list  of  the  North  American  fossil  species  belonging  to  the 
Testudinidae  so  arranged  as  to  exhibit  their  geological  sequence: 


Pleistocene. 
Pliocene. 

Miocene. 

Oligocene. 

Eocene. 

'                                                                       Species. 

Equus,  or 
Sheridan  beds. 

Peace  Creek. 

Testudo  hexagonata,  T.  laticaudata,  T.  atascosae  (Texas). 

Testudo  crassiscutata  (Florida). 

Blanco. 

Testudo  pertenuis,  T.  turgida,  T.  campester  (Texas). 

Loup  Fork. 

Testudo  klettiana,  T.  undata  (New  Mexico);    T.  niobrariensis,  T.  hollandi,  T.  edae 
(Nebraska);    T.   impensa  (Montana);   T.  gilberti,  T.  orthopygia    (Kansas);    T. 
arenivaga  (Nebraska). 

Deep  River 

and 

Pawnee  Creek. 

Testudo  pansa,  T.  osborniana  (Colorado);  T.  arenivaga  (Nebraska);    T.  emilias  (South 

Dakota). 
Testudo  vaga  (Wyoming);    .>T.  peragrans,  T.  farri,  T.  inusitata  (Montana). 

John  Day. 

Stylemys  conspecta,  S.  capax  (Oregon);  S.  calaverensis  (California). 

Testudo  brontopSjT.thoinsoni  (South  Dakota);    .'T.  peragrans  (Montana);    T.ligonia, 
„,,.      „.                      T.  cultrata,  T.  laticunea,  T.  amphithorax,  T.  quadrata  (Colorado);    T.  eiornata 
(Assiniboia);    Stylernvs  nebrascensis  (South   Dakota,   North    Dakota,  Nebraska, 
Wyoming). 

Unita. 

Hadrianus  tumidus  (Utah).               ,_^ 

Jackson. 

Hadrianus  schucherti  (Mississippi). 

Bridger. 

Hadrianus  corsoni  (Wyoming);    Achilemys  allabiata  (Wyoming). 

Wasatch. 

Hadrianus  majusculus  (New  Mexico);   H.  corsoni .'  (New  Mexico). 

Puerco. 

.     — ..-..                 « 

We  can  not  doubt  that  the  predecessors  of  Hadrianus  will  yet  be  found  in  the  Puerco  beds 
or  their  equivalents.  We  may  even  look  confidently  for  more  primitively  constructed  Tes- 
tudinidae in  some  of  the  Upper  Cretaceous  deposits.  They  are  more  likely  to  occur  in  river 
valley  formations  or  aeolian  accumulations. 

Considering  the  large  size  of  Testudo  brontops,  the  grade  of  its  differentiations,  and  the 
great  number  of  species  of  Testudo  which  made  their  appearance  in  the  Oreodon  beds  of  the 
Oligocene  we  may  be  sure  that  species  of  the  genus  will  yet  be  discovered  in  some  of  the  upper 
formations  of  the  Eocene  of  America;  as  they  have  already  been  found  in  the  Upper  Eocene 
of  northern  Africa. 

Nevertheless,  it  seems  to  the  writer  that  the  family  was,  in  the  earlier  half  of  the  Eocene, 
in  a  stage  of  development  represented  by  Hadrianus  corsoni  of  the  Bridger,  and  that  Testudo 
brontops,  with  its  only  slightly  differentiated  costal  plates,  represents  a  stage  which  existed 
possibly  even  in  the  Upper  Eocene.  It  may  be  concluded  therefore  that  any  members  of  the 
family  that  shall  be  found  in  the  Puerco  and  Upper  Cretaceous  will  display  further  approxi- 
mations to  the  Emydidae. 

It  will  be  interesting  to  consider  in  the  light  of  knowledge  derived  from  both  the  living  and 
the  fossil  species  of  the  family  the  special  characters  which  they  have  developt  since  their  first 
appearance:  as  we  might  say,  the  goal  toward  which  they  have  been  striving. 

With  regard  to  the  shell  we  see  that  it  is  usually  very  high  and  convex.  There  are  various 
exceptions  to  this  statement;  nevertheless,  we  find  no  species  so  deprest  as  some  of  the  Emy- 
didae;  and  the  height  and  convexity  will  average  much  higher  than  among  the  species  of  the 


testudinidt*.  369 

latter  family.  The  ends  to  be  subserved  by  this  convexity  may  be  various.  We  may  suppose 
that  it  would  be  much  more  difficult  for  a  carnivorous  animal  to  effect  an  entrance  into  such 
a  shell  than  into  one  deprest  and  whose  borders  may  be  spanned  by  the  jaws  of  the  enemy. 
Again,  the  vauhed  shell  provides  greater  space  for  the  lungs;  and  the  investigations  credited 
by  Hoffmann  (Brown's  Klass.  and  Ordn.:  Schildkr.,  p.  344)  to  Dr.  Joseph  Jones  but  really 
made  by  Louis  Agassiz  (Contrib.  Nat.  Hist.  U.  S.,vol.  i,  p.  283)  show  that  the  capacity  of  the 
lungs  of  Gopherus  polyphemus  is  much  greater  than  that  of  Emydidae  having  an  equal  length 
of  shell,  except  Terrapene,  which  has  similar  habits  of  life.  Even  the  earlier  known  forms  of 
the  Testudinidae,  as  Hadrianus  and  Stylemys,  have  the  shell  high  and  vaulted;  and  this  fact 
suggests  that  the  deprest  form  of  some  existing  species  may  be  due  to  adaptations  to  recent 
conditions.  The  flattened  carapace  of  Gopherus  polyphemus,  for  instance,  may  have  relation 
to  the  burrowing  habits  of  the  species. 

Among  the  Emydidae  the  neural  bones  are  usually  hexagonal,  with  the  broader  end  of  the 
bone  in  front.  Such,  too,  is  the  case  with  some  of  the  Testudinidae.  In  Stylemys  nebrascensis 
we  find  this  condition  prevailing;  but  occasionally  a  specimen  is  found  in  which  the  second 
one  is  octagonal.  In  S.  conspecta  and  S.  capax,  of  the  John  Day  beds,  there  is  further  advance- 
ment— the  second  is  octagonal,  while  the  third  is  tetragonal.  Too  much  weight  ought  not  to 
be  attacht  to  single  specimens  having  modifications  of  this  sort;  as  is  illustrated  by  the  fact 
that  in  the  American  Museum  of  Natural  History  there  is  a  specimen  of  Chelydra  serpentina 
in  which  the  second,  fourth,  and  fifth  neurals  are  octagonal,  while  the  third  is  tetragonal. 
Nevertheless,  among  the  Testudinidae  a  high  degree  of  differentiation  of  the  neurals  is  the  rule. 
When  we  come  to  the  genus  Testudo  itself  we  find  the  alternation  of  octagonal  with  tetragonal 
neurals  the  prevailing  arrangement.  In  Kinyxis,  according  to  Boulenger's  figure  (Cat. 
Chelonians,  fig.  41),  the  neurals  are  hexagonal  with  the  broad  end  behind,  a  form  the  reverse 
of  that  common  among  the  Emydidae.  In  Homopus  the  emydoid  condition  prevails,  except 
that  the  third  is  tetragonal. 

The  costals  have  suffered  remarkable  modifications  among  the  Testudinidx.  In  most 
other  turtles  these  plates,  from  the  second  to  the  sixth  inclusive,  have  the  proximal  and  the 
distal  ends  of  each  costal  of  nearly  the  same  width.  In  most  species  of  Testudo  and  in  Gopherus 
the  proximal  ends  of  the  second,  fourth,  and  sixth  are  much  narrowed,  while  the  distal  ends 
are  greatly  widened.  On  the  other  hand,  the  proximal  ends  of  the  third  and  fifth  are  broad, 
while  the  distal  ends  are  narrow.  The  proximal  ends  of  costals  3  and  4  are  in  contact  with  3 
neurals  each.  The  5  costals  concerned  appear  thus  to  be  dovetailed  with  one  another.  The 
mechanical  advantages  of  this  arrangement  have  been  discust  by  A.  Bienz  (Rev.  suisse 
Zool.,  etc.,  in,  1895,  p.  99).  These  modifications  of  the  costals  are  not  conspicuous  in  Had- 
rianus and  in  Stylemys  nebrascensis,  but  they  become  very  manifest  in  the  species  of  Stylemys 
from  the  John  Day  beds.  In  Testudo  brontops  of  the  lowest  Oligocene,  the  neurals  display  a 
high  grade  of  differentiation,  and,  in  harmony  with  this,  the  upper  ends  of  the  costals  are  modi- 
fied so  as  to  unite  alternately  with  I  and  with  3  neurals;  but  there  is  no  great  difference  in  the 
widths  of  the  upper  and  lower  ends  of  each  costal. 

In  most  turtles  the  position  of  the  rib  is  very  distinctly  shown  on  the  visceral  side  of  each 
costal  plate;  and  the  heads  of  the  ribs  are  broad  and  thick.  These  heads  join  their  respective 
vertebral  centra  at  the  anterior  ends  of  the  latter,  and  at  least  the  anterior  ones  come  into 
contact  also  with  the  next  centrum  in  advance.  In  the  Testudinidae  the  ribs  show  only  faintly 
on  the  under  side  of  the  costals  and  the  rib-heads  are  usually  greatly  reduced.  In  a  specimen 
of  Testudo  radiata  from  Madagascar,  having  the  shell  305  mm.  long,  the  rib-heads  of  the 
second  to  the  sixth  costal  plates  may  be  30  mm.  long;  but  they  are  very  slender  blades  5  mm. 
thick  horizontally  and  2  mm.  high,  expanding  somewhat  toward  the  proximal  ends.  In 
Gopherus  only  the  merest  traces  of  the  rib-heads  remain  of  those  belonging  to  the  costals  in 
front  of  the  seventh;  and  these  vestiges  adhere  to  the  centra  and  to  the  neural.  In  T.  tabulata 
the  rib-heads  are  all  much  reduced.  Many  of  these  are  wholly  free  from  the  costal  plates  and 
have  become  co-ossified  with  the  under  sides  of  the  neural  bones.  Intermediate  stages  are  to 
be  seen  in  this  species.  This  condition  illustrates  well  the  manner  in  which  the  ribs,  probably 
free  from  the  costals  in  the  most  primitive  turtles,  have  become  consolidated  with  them. 

When  we  examine  Hadrianus  we  find  that  the  rib-heads  were  somewhat  reduced,  but  still 
of  considerable  size.     In  Stylemys  they  are  still  more  reduced.     A  careful  examination  of  a 
24 


370  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

series  of  fossil  turtles  of  the  various  geological  periods  would  doubtless  show  a  gradual  reduction 
of  the  size  of  the  rib-heads  in  this  family. 

The  distal  ends  of  the  costal  ribs  of  the  Testudinidae  have  become  reduced  in  an  interesting 
way.  In  the  great  majority  of  turtles  the  distal  ends  of  these  ribs  project  more  or  less  beyond 
the  margins  of  the  costal  plates,  and  the  projecting  ends  are  usually  received  by  pits  in  the 
adjacent  peripherals.  In  most  of  the  Testudinidae  the  ends  of  the  ribs  have  disappeared. 
In  Gopherus  we  find  that,  instead  of  the  rib  entering  the  peripheral,  a  broad  process  of  the 
peripheral  rises  and  enters  a  notch  on  the  inside  of  the  costal  plate,  an  interesting  reversal  of 
conditions.  The  relations  of  the  ribs  and  peripherals  in  T .  radtata  are  very  similar.  In  T . 
tabulata  no  conspicuous  process  is  found  on  either  the  costal  plate  or  on  the  peripheral.  In 
Hadrianus,  as  in  Gopherus  and  most  species  of  Testudo,  a  process  of  the  peripheral  enters  an 
excavation  in  the  inner  surface  of  the  costal.  On  the  other  hand,  in  Stylemys  the  extremity 
of  the  rib  fits  into  a  pit  in  a  peripheral,  just  as  in  the  Emydidae. 

In  typical  Testudinidae  of  to-day  the  peripherals  and  contiguous  costals  are  articulated, 
not  only  by  the  processes  just  described,  but  also  by  digitating  sutures,  and  these  are  usually 
better  developt  than  in  the  Emydidse.  In  T.  radtata  long  shvers  of  bone  arising  from  the 
peripherals  interdigitate  with  shorter  processes  from  the  costals.  On  the  other  hand,  in 
Siylenivs  and  Hadrianus  there  appear  to  have  been  no  such  digitations;  but  the  rounded 
border  of  each  peripheral  joins  the  similar  border  of  the  neighboring  costal. 

In  the  majority  of  the  Testudinidae  the  epiplastral  bones  are  thickened  for  some  distance 
on  each  side  of  their  symphysis.  The  thickening  takes  place  on  the  upper  side  of  the  bones. 
At  the  hinder  border  of  the  thickening,  on  each  side  of  the  midline,  the  elevation  drops  off 
suddenly  to  the  level  of  the  entoplastron.  In  many  species  the  ledge  thus  formed  and  looking 
backward  is  excavated  more  or  less  deeply.  Usually  the  thickened  epiplastra  project  more  or 
less  beyond  the  general  curve  of  the  rest  of  the  anterior  lobe,  and  there  is  thus  formed  a  con- 
spicuous epiplastral  lip.  This  lip  presents  various  forms  in  the  different  species  and,  tho 
subject  to  variations,  it  furnishes  valuable  specific  characters.  The  lip  is  conspicuously 
developt  in  Hadrianus,  as  in  most  species  of  Testudo.  In  Stylemys  the  front  of  the  epiplastra 
is  thickened,  but  it  does  not  project  beyond  the  curvature  of  the  rest  of  the  lobe. 

The  hinder  end  of  the  plastron  is  usually,  but  not  always,  notcht. 

At  the  anterior  ends  of  the  bridges  the  hyoplastron  of  each  side  sends  upward  a  process, 
the  axillary  buttress,  which  articulates  with  the  first  costal  plate.  Usually  this  buttress  does  not 
pass  above  the  lower  border  of  the  costal.  At  the  hinder  end  of  the  bridge  the  hypoplastron 
sends  up  an  inguinal  buttress,  which  also  rarely  rises  above  the  lower  border  of  the  costals 
involved.  In  Gopherus  and  the  species  of  Testudo  already  mentioned  this  buttress  is  articu- 
lated with  the  middle  of  the  lower  border  of  the  sixth  costal;  but  it  appears  that  in  some 
other  living  genera  of  the  family,  possibly  in  some  other  species  of  Testudo,  the  buttress  is 
attacht  somewhat  further  forward.  In  Hadrianus  corsoni  the  buttress  ascends  a  short  distance 
on  the  inner  side  of  the  sixth  costal.  In  Stylemys  nebrascensis  it  is  articulated  between  the  fifth 
and  sixth  costals,  rising  a  short  distance  above  their  lower  borders.  It  is  evident  that  there  has 
been  a  tendency  among  the  Testudinidae  to  push  the  buttress  backward,  and  thus  increase 
the  width  of  the  bridge.  The  purpose  has  apparently  been  to  diminish  as  much  as  possible 
the  hinder  opening  of  the  shell. 

The  shoulder-girdle  of  the  Testudinidae  appears  to  be  distinguisht  from  that  of  the 
Emydidae  in  two  respects:  The  coracoid  is  greatly  expanded  at  its  inner,  or  mesial  border,  and 
the  procoracoid  process  makes  an  obtuse  angle  with  the  body  of  the  scapula.  Probably  in  all 
Emydidae  the  coracoid  is  only  slightly  expanded  at  the  mesial  border  and  the  procoracoid 
process  makes  an  acute  angle  with  the  body  of  the  bone. 

The  humerus,  in  probably  all  members  of  the  family,  is  characterized  by  having  the  radial 
and  ulnar  processes  both  twisted  toward  the  ventral  side  of  the  bone,  thus  making  the  angle 
between  them  small.  Usually  the  humerus  is  considerably  bent,  but  often  no  more  so  than  in 
some  species  of  Emydidae. 

In  most  species  of  the  family  there  are  5  digits  belonging  to  each  forelimb;  but  occasionally 
there  are  only  4.  No  digit  possesses  more  than  2  phalanges.  How  this  reduction  has  been 
brought  about  is  an  interesting  question.  A  similar  reduction  of  the  phalanges  to  two  in  each 
digit  occurs  in  the  forefoot  of  Terrapene  as  observed  bv  Dr.  George  Baur  (Zool.  Anzeiger,  xv, 
J892,  p.  159), 


TESTUDINID^.  371 

The  metacarpal  bones  are  very  short,  usually  broader  than  long.  The  whole  foot  is  short 
and  heavy,  resembling  that  of  an  elephant. 

The  pelvis  is  constructed  on  the  plan  of  that  of  the  Emydidae. 

The  femur  is  distinguisht  from  that  of  the  Emydidae  in  the  union  of  the  two  trochanters 
by  a  ridge  which  runs  nearly  on  the  level  of  the  head  of  the  bone,  when  the  femur  is  held  perpen- 
dicularly. Between  this  ridge  and  the  head  there  is  a  pit  of  some  depth.  The  metatarsals  and 
the  phalanges  are  not  so  short  as  the  corresponding  bones  of  the  forelimb;  but  they  are  much 
shorter  than  those  of  the  Emydidae.  There  are  only  4  digits,  the  fifth  metatarsal  being  reduced 
to  a  rudiment.    No  digit  has  more  than  2  phalanges. 

Little  is  known  regarding  the  feet  oi Hadrianus,  but  we  may  confidently  expect  to  find  only 
2  phalanges  in  each  digit.  While  the  structure  of  the  digits  of  Stylemys  is  not  certainly  deter- 
mined all  the  known  facts  point  to  conditions  similar  to  those  found  in  the  other  genera  of  the 
family. 

The  most  striking  differences  between  the  skulls  of  the  Testudinidae  and  those  of  the  Emy- 
didse  are  found  in  the  excavation  of  the  roof  of  the  mouth  of  the  members  of  the  former 
family  and  in  the  closure  of  the  stapedial  notch.  The  palate  rises  high  above  the  level  of  the 
crushing-surfaces  of  the  upper  jaws  and  the  vault  thus  formed  is  carried  back  to  between  the 
quadrates.  The  skull  of  Hadrianus  is  wholly  unknown.  The  skull  of  Stylemys  presents  the 
same  vaulting  as  that  ot  Testudo. 

The  geographical  distribution  of  the  Testudinidae  (fig.  14,  p.  33)  within  historical  times  is  a 
most  important  and  interesting  question,  and  it  has  within  recent  years  provoked  much  dis- 
cussion. Dr.  Albert  Giinther  (Proc.  Linnean  Soc.  Lond.,  ex,  1898,  p.  26),  as  an  appendix  to 
his  presidential  address  on  this  subject,  has  given  a  list  of  51  papers  which  have  a  bearing  on 
the  question.  The  most  difficult  question  to  settle  is  how  the  ancestors  of  the  gigantic  tortoises 
which  once  abounded  on  the  Galapagos  Islands  and  on  various  groups  in  the  Indian  Ocean 
reacht  those  islands.  Originally  it  was  assumed  that  these  ancestors  were  accidental  arrivals, 
borne  thither  by  oceanic  currents;  but  in  1891  Dr.  George  Baur  (Amer.  Naturahst,  xxv, 
pp.  217-229;  307-326)  promulgated  the  theory  that  these  islands  were  only  the  volcanic  peaks 
of  a  great  tract  of  land  which  had  at  one  time  connected  these  islands  with  one  another  and 
with  the  western  coast  of  America.  In  a  number  of  papers  succeeding  this  announcement  he 
defended  this  theory.  For  Dr.  Baur's  views  the  reader  is  referred  to  his  writings,  a  list  of  which 
was  publisht  by  Dr.  W.  M.  Wheeler  in  1899  (Amer.  Naturahst,  xxxiii,  pp.  23-30). 

The  present  writer  does  not  intend  to  enter  upon  a  full  discussion  of  the  question,  but  he 
records  it  as  his  conviction  that  in  general  terms  Dr.  Baur's  position  is  correct.  Probably  the 
simplest  way  to  account,  on  the  old  theory,  for  the  presence  of  these  tortoises  on  these  remote 
islands  is  to  suppose  that,  some  time  in  the  distant  past,  a  gravid  female  was  borne  by  currents, 
swimming  or  floating  on  a  raft  of  fallen  timber;  that  she  landed  on  one  of  the  islands;  and  that 
her  descendants  were  in  some  similar  way  distributed  to  the  other  islands  of  the  group.  But 
these  Testudinidae  are  probably  of  all  turtles  the  least  adapted  for  such  transportation.  In  the 
water  they  would  almost  certainly  drown  within  a  few  hours.  Nor  is  it  probable  that  a  raft  of 
wood  would  hold  together  long  enough  or  well  enough  to  carry  one  of  these  turtles, wholly  incap- 
able of  clinging  to  such  objects,  the  distance  of  700  miles.  If  this  almost  miracle  of  transpor- 
tation had  been  accomplisht,  it  must  have  been  repeated  on  a  smaller  scale  many  times,  in 
order  to  populate  the  various  islands.  And  all  this  work  must  have  been  accomplisht  long  ago, 
and  long  ago  have  ceast;  have  been  accomplisht  long  enough  ago  to  permit  the  evolution  of 
a  distinct  species  on  each  island,  and  have  ceast  long  enough  ago  that  new  arrivals  should 
not  have  disturbed  this  differentiation.  It  is  difficult  to  imagine  why  the  distribution  of  these 
turtles  between  the  various  islands  should  not  have  continued,  if  it  had  ever  been  possible. 

Probably  the  chances  for  lizards  to  reach  the  Galapagos  Islands  from  the  American  coast 
and  from  one  island  to  the  other  are  much  better  than  those  favoring  the  turtles.  Yet  we  find 
the  same  variation  among  the  lizards  of  the  islands  that  we  find  among  the  turtles.  Four 
genera  are  represented  on  these  islands,  of  which  two,  Tropidurus  and  Phyllodactylus,  are 
represented  on  the  American  coast.  Two  others,  Conolophus  and  Amblyrhynchus,  are  peculiar 
to  the  islands  in  question.  It  seems  that  the  opportunities  for  the  accidental  transportation  of 
lizards  are  to-day  as  good  as  they  could  ever  have  been,  yet  no  species  are  common  to  the 
American  coast  and  the  Galapagos  Islands.    We  would  be  justified  in  expecting  something 


.■57^ 


FOSSIL    TURTLIiS    OK    NORTH    AMERICA. 


more  than  a  few  common  species.  Along  the  western  coast  of  Central  and  South  America,  in 
situations  where  they  are  hable  to  be  carried  down  by  rivers  to  the  Pacific  Ocean,  there  Hve 
about  50  genera  of  hzards.  How  can  it  be  explained  that  such  a  fragment  of  these  has  reacht 
the  Galapagos  Islands  ? 

An  instructive  chart,  publisht  by  Dr.  Alexander  Agassiz  (Bull.  Mus.  Comp.  Zool.,  xxiii, 
pp.  56-74,  plate  iii)  exhibits  the  floor  of  the  ocean  in  that  region,  and  demonstrates  the  presence 
of  a  tongue  of  uplift  which  extends  from  the  Galapagos  Islands  to  the  Central  American  coast 
just  north  of  the  Gulf  of  Panama.  It  seems  therefore  probable  that  at  some  time  in  the  past, 
evidently  after  the  Oligocene,  more  probably  during  the  Miocene,  there  existed  a  mass  of  land 
which  included  the  Galapagos  Islands  and  joined  narrowly  the  Central  American  coast.  This 
land  mass  might  be  compared  to  the  island  of  Madagascar,  with  the  long  axis  at  right  angles 
with  the  neighboring  continent,  instead  of  parallel  with  it.  Over  the  narrow  bridge  there 
past  the  ancestors  of  the  present  turtles  of  those  islands  and  a  few  genera  of  lizards,  together 
with  some  other  animals  and  sundry  plants.  The  descendants  of  these  invaders  have  differen- 
tiated and  formed  a  part  of  the  present  fauna  and  flora  of  the  islands.  It  is  not  unlikely  that 
some  genera  which  invaded  that  land  perisht  afterwards. 

When  we  try  to  account  for  the  presence  of  the  gigantic  tortoises  found  at  one  time,  but  now 
nearly  extinct,  on  the  islands  of  the  Indian  Ocean,  we  are  met  with  the  same  difficulties  that 
we  have  been  considering.  If  the  conformation  of  the  land  and  sea  was  the  same  as  now  when 
the  ancestors  of  these  tortoises  reacht  their  island  homes,  they  must  have  been  transported  over 
the  seas  for  distances  varying  from  250  to  750  miles. 

The  solution  of  the  various  problems  connected  with  the  distribution  of  animals  and  plants 
in  southern  Africa  and  southern  Asia  and  the  islands  of  the  Indian  Ocean  have  driven  many 
geologists,  zoologists,  and  botanists  to  the  conclusion  that  at  one  time  there  was  a  land  connect- 
tion  between  India  and  South  Africa,  across  the  Indian  Ocean.  For  a  masterly  discussion 
of  this  question  the  reader  is  referred  to  the  presidential  address  of  Mr.  W.  T.  Blanford  before 
the  Geological  Society  of  London  in  1896  (Quart.  Jour.  Geol.  Soc.  Proc,  p.  98),  and  also  to 
Gunther's  address  already  cited.  Blanford  concludes  that  there  was  such  a  land  connection 
as  has  been  mentioned  above,  that  this  continued  thruout  the  Upper  Cretaceous,  and  was 
broken  up  into  islands  at  an  early  Tertiary  date.  Dr.  Giinther  adopts  this  conclusion  and  adds 
that  "the  slow  evolution  of  this  chelonian  type  {Testudo)  which  has  scarcely  changed  since 
the  Eocene,  and  its  wide  distribution  over  the  Northern  Hemisphere,  justify  the  supposition 
that  it  was  in  existence  already  before  the  Tertiary,  before  the  bridge  was  broken  through 
which  allowed  of  its  passage  southwards  or  northwards." 

That  primitive  Testudinidae  were  in  existence  toward  the  close  of  the  Upper  Cretaceous  is 
very  probable,  but  that  the  genus  Testudo  had  at  that  time  made  its  appearance  there  is  no 
proof,  no  probability.  We  do  not  know  of  its  existence  with  certainty  before  the  Upper  Eocene 
in  Africa  and  the  lowest  Oligocene  in  America.  The  less  advanct  forms  of  the  family,  as 
Hadrtanus  and  related  genera,  may  have  reacht  India  or  South  Africa  by  the  end  of  the 
Cretaceous,  but  we  have  no  evidence  of  this.  Hence,  unless  we  are  willing  to  betake  ourselves 
to  what  ought  to  be  our  last  refuge  and  hold  that  Testudo  had  a  polyphyletic  origin  (using  this 
term  in  its  original  sense),  that  the  Testudos  of  America  and  those  of  the  eastern  continents 
sprang  independently  from  Hadrtanus  or  from  the  latter  genus  and  another,  we  must  place  at 
a  later  date  than  the  early  Eocene  the  arrival  of  the  ancestors  of  the  gigantic  tortoises  on  Mada- 
gascar and  the  islands  of  the  western  portion  of  the  Indian  Ocean. 

The  conclusion  reacht  by  Mr.  Richard  Lydekker  regarding  the  time  of  separation  of  Mad- 
agascar from  the  mainland  was  that  this  occurred  during  the  Miocene  (Geog.  Hist.  Mammals, 
p.  223).  Mr.  Blanford  had  previously  concluded  that  the  depression  of  1,000  fathoms  or  more 
which  led  to  the  formation  of  the  Mozambique  Channel  had  taken  place  during  Pliocene  or 
Postpliocene  times.  However,  the  recent  discovery  of  species  that  can  hardly  be  separated 
from  Testudo,  in  the  Fayum  in  Egypt,  makes  it  necessary  to  recognize  the  fact  that  members  of 
the  genus  had  reacht  that  continent  as  early  at  least  as  the  Upper  Eocene. 

Testudinidae  at  their  various  stages  of  development  are  known  at  earlier  dates  in  North 
America  than  elsewhere.  It  seems  therefore  probable  that  North  America  was  their  center  of 
distribution.  From  western  North  America  they  may  be  supposed  to  have  reacht  Central 
America  and  to  have  migrated  thence  to  the  present  Galapagos  Islands.    From  western  North 


TESTUDINID^. 


373 


America,  taking  a  northwestern  direction,  they  past  into  Asia  over  the  bridge  of  land  which 
occupied  the  position  of  Bering  Strait.  Passing  westward  they  entered  Europe.  Others 
spreading  southwestward  peopled  India  and  the  strip  of  land  which  connected  the  latter 
country  with  Africa,  and  which  now,  greatly  deprest,  is  represented  by  Madagascar  and 
various  groups  of  islands.    From  this  land  they  entered  Africa  itself. 

The  living  Testudinidae  which  have  been  designated  as  "gigantic  tortoises"  all  belong  to 
the  genus  Testudo.  The  species  of  Hadrianus  of  the  Eocene  were  worthy  of  being  called 
gigantic.  That  the  gigantic  forms,  living  and  extinct,  may,  in  some  cases,  have  been  derived 
from  small  species  and  that  some  of  the  smaller  modern  species  are  the  descendants  of  extinct 
gigantic  ancestors,  are  possibilities.  Within  historical  times  gigantic  tortoises  have  lived  only 
on  islands,  where  there  are  no  large  carnivorous  mammals.  On  the  other  hand,  the  large 
Testudinidae  of  North  America,  from  the  Lower  Eocene  to  the  Pliocene,  were  exposed  to  the 
attacks  of  large  carnivora. 

As  remarkt  by  Mr.  R.  Lydekker,  the  gigantic  tortoises  became  extinct  on  all  the  conti- 
nents at  the  close  of  the  Pliocene.    This  appears  to  be  true  of  North  America,  since  the  3  species 


Fig.  471. — Testudo  sumeirei.     View  of  living  animal.     After  Rothschild'sfigure,  greatly  reduced. 

recorded  from  the  Equus  beds  are  all  of  moderate  size.  Nevertheless,  Dr.  Leidy  has  figured 
the  claw  phalange  (Cont.  Extinct  Vert.  Fauna  West.  Terrs.,  1873,  pi.  xxxiii,  fig.  21)  of  a  species 
of  Testudo  found  in  Pleistocene  deposits  in  Hardin  County,  Texas.  The  individual  must 
have  been  one  of  great  size.  This  phalange  is  now  in  the  American  Museum.  We  do  not 
know  why  some  of  the  Pliocene  gigantic  tortoises  should  not  have  had  descendants  in  the 
Quaternary  worthy  of  accompanying  the  great  mammals  of  that  period. 

Fig.  470  represents  Testudo  sumeirei  Sauzier,  a  gigantic  tortoise  living  in  Port  Louis, 
Mauritius.  This  figure  is  reproduced  from  a  plate  publisht  by  the  Hon.  Walter  Rothschild 
(Novitates  Zoologicae,  i,  1894,  plate  xi)  over  the  name  Testudo  indica.  This  tortoise  was  men- 
tioned in  a  treaty  made  in  1810.  The  length  of  the  carapace  is  40  inches  (1015  mm.);  that  ol 
the  plastron,  28  inches  (711  mm.). 

Analysis  of  Genera. 

A.  Epiplastral  lip  projecting  abruptly  from  front  of  carapace. 

a.  Neural  bones  hexagonal.   Eocene  species Hndrianus 

aa.  Usually  some  octagonal  and  quadrangular  neurals;  Oligocene  to  Recent  species.  .  .  Testudo 
A  A.  Epiplastral  lip  not  projecting  abruptly  or  far  beyond  gulo-humeral  sulci. 

b.   Epiplastral  lip  not  thickened  backward  above;    Bridger Aehilemys 

hh.   Epiplastral  lip  thickened  backward  above;  Oligocene Stylemys 

Genus  HADRIANUS  Cope. 
Testudinidae  with  the  plastron  extensively  united  to  the  carapace  by  suture;    with  short 
axillary  and  inguinal  buttresses,  the  latter  of  which  ascend  within  the  sixth  costal  plates;   no 
plastral  hinge.    Epiplastral  lip  strongly  developt;  entoplastron  wholly  in  front  of  the  pectoral 


374  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

scutes;  hinder  lobe  of  plastron  notcht.  Ofthe  neural  plates  the  second  and  third  are  hexagonal 
with  the  shortest  sides  directed  backward;  the  third  is  quadrilateral;  and  the  remainder  are 
hexagonal,  with  the  shortest  sides  directed  forward.  Three  suprapygals,  of  which  the  penulti- 
mate is  notcht  behind  and  receives  the  third.  Costals  with  no  great  difference  between  the 
widths  ofthe  proximal  and  distal  ends.  Two  supracaudal  scutes.  Shoulder  and  pelvic  girdles 
as  in  Testudo.  Skull  unknown.  Cervical  vertebrae  and  limb  bones  not  well  known. 
Type:    Testudo  corsoni  Leidy. 

Without  having  the  skull  and  the  distal  limb  bones,  it  is  not  possible  to  say  positively  that 
this  genus  belongs  to  the  Testudinidse,  as  limited  in  this  work.  The  shell  and  shoulder  and 
pelvic  girdles,  however,  present  many  characters  which  indicate  close  relationships  with  the 
modern  land-tortoises.  We  find  in  this  genus  apparently  the  beginnings  of  those  modifications 
of  the  shell  which  characterize  the  genus  Testudo.  In  most  species  of  the  latter  the  neural 
plates  are  alternately  tetragonal  and  hexagonal;  and  the  second,  fourth,  and  sixth  costals  are 
narrow  at  the  proximal  ends  and  wide  at  the  distal  ends,  while  the  third,  fifth,  and  seventh  are 
wide  proximally  and  narrow  distally.  In  Hadrianus  the  third  neural  is  quadrate,  as  in  Testudo, 
and  the  corresponding  costals  are  widened  proximally  to  come  into  contact  each  with  three 
neurals  also,  as  in  Testudo.  The  other  costals  differ  only  slightly  in  the  widths  of  their  opposite 
ends.  As  in  Testudo,  the  connection  between  the  costals  and  the  peripherals  is  a  rather  loose 
one;  the  sulcus  between  the  costal  and  marginal  scutes  follows  closely  the  sutures  between  the 
peripheral  and  costal  bones;  the  epiplastrals  form  a  conspicuous  lip;  the  humero-pectoral 
sulcus  falls  behind  the  entoplastron;  and  the  pectoral  scutes  are  rather  narrow.  Even  Stylemys, 
belonging  to  a  later  period,  appears  to  be  less  advanct  in  many  respects  than  Hadrianus. 

In  various  writings  (the  latest  being  his  Vertebrata  ofthe  Tertiary  Formations  ofthe  West, 
1884,  p.  113)  Prof.  E.  D.  Cope  assigned  as  the  character  distinguishing /fat/r/awuj^  from  the 
other  Testudinidx  a  divided  supracaudal  scute.  Three  species  of  the  genus  Testudo,  as 
recognized  by  Boulenger,  also  have  this  scute  divided.  It  seems  to  the  author  that  the  un- 
differentiated condition  of  the  shell  furnishes  a  more  satisfactory  basis  for  the  genus.  Mr. 
Richard  Lydekker  (Cat.  Foss.  Rept.  and  Amphib.  Brit.  Mus.,  in,  p.  72)  gives,  among  other 
characters  distinguishing  Hadrianus,  the  "narrow  vertebral  shields  and  the  elongated  neural 
bones  which  are  hexagonal,  with  short  postero-lateral  surfaces"  [sides].  The  neurals,  however, 
are  not  of  unusual  narrowness.  As  to  their  form,  Mr.  Lydekker  cites  a  figure  by  Leidy  which 
represents  only  the  3  anterior  neurals,  but  another  figure  by  Leidy  in  the  same  work  (Ext. 
Vert.  Fauna  West.  Terrs,  plate  xxx,  fig.  i)  shows  that  the  fourth  and  fifth  neurals  have  the 
antero-lateral  sides  short. 

So  far  as  known  at  present  the  members  of  this  genus  are  confined  to  the  Eocene.  The 
oldest-known  species  is  H.  majusculus  Hay  from  the  Wasatch  of  New  Mexico;  the  most 
recent  species  is  H.  tumidus  Hay,  from  the  Upper  Uinta.  As  suggested  by  Mr.  Lydekker, 
some  of  the  Eocene  and  Miocene  species  of  Europe  that  have  been  referred  to  Testudo  may  in 
reality  belong  to  Hadrianus. 

Analysis  of  the  Known  Species. 

1.  Wasatch.    Very  high  peripherals.    Pectoral  scutes  more  than  half  as  wide  along  midline 

as  the  abdominals majusculus 

2.  Bridget.     Peripherals  of  moderate  height.     Pectoral  scutes  less  than  half  as  wide  on  mid- 

line as  the  abdominals corsoni 

J.Uinta.    Peripherals  high.    Pectoral  scutes  less  than  one-third  as  wide  as  the  abdominals.  .         tumidus 
4.  Jackson  formation.  Pectoral  scutes  one-ninth  as  wide  as  the  abdominals schucherti 

Hadrianus  majusculus  Hay. 

Plate  59,  fig.  i;   text-fig.  471. 

fHadrianus  corsonii,  CoPE,  Syst.  Cat.  Vertebrata  Eocene  N.  Mex.,  1874,  p.  36;  Append.  LL.  Ann.  Rep. 

Chief  Engineers  (Wheeler's  Surv.),  1875,  p.  1016  (separata,  p.  96) 
Hadrianus  majusculus,  Hay,  Amer.  Jour.  Sci.,  (4),  xviil,  1904,  p.  271,  plate  xv;  text-fig.  5. 

The  species  here  described  is  founded  on  a  somewhat  damaged  shell  which  belongs  to  the 
Marsh  collection  in  Peabody  Museum,  at  Yale  University.  Accompanying  this  shell  is  a  label 
which  bears  the  following  record:  "Turtle  from  foot  of  bluff,  west  side  of  Murderer's  Gap. 


TESTUDINIDiR.  375 

In  large  fragment  of  sandstone  that  had  fallen  from  the  bluff.  Nov.  19,  1876.  D.  Baldwin." 
Another  label  states  that  the  specimen  came  from  the  "Eocene  Bad  Lands,  Gallina,  New 
Mexico."  This  locality  appears  to  he  in  Rio  Arriba  County,  of  the  territory  mentioned. 
The  deposits  whence  the  shell  was  derived  are  in  all  probability  a  portion  of  the  Wasatch.  On 
the  carapace  is  found  Professor  Marsh's  receipt  number  927. 

The  specimen  is  somewhat  distorted  and  injured  by  pressure,  being  slightly  comprest  and 
thrust  toward  the  left  side.  Crushing  has  also  affected  the  upper  median  region,  so  that  most 
of  the  neurals  have  been  displaced.  At  a  later  time  these  were  weathered  and  fractured;  and  it 
is  now  quite  impossible  to  restore  them  to  their  proper  positions.  The  right  border  from  the 
fifth  peripheral  to  the  tenth  has  been  weathered  and  removed.  In  the  same  way  the  right  side 
of  the  hinder  part  of  the  plastron  has  been  damaged. 

The  length  of  the  carapace  (plate  59,  fig.  I )  in  a  direct  line  is  530  mm.  The  greatest  width 
was  at  least  440  mm.  In  form  it  was  high  and  archt.  Over  the  limbs  the  peripherals  were  con- 
siderably flared.  The  anterior  border  was  truncate;  the  hinder  border  rounded  and  scallopt. 
The  free  borders  of  all  the  anterior  and  posterior  peripherals  have  acute  edges. 

On  account  of  crushing  the  dimensions  of  the  nuchal  bone  can  not  be  determined.  Appar- 
ently it  extends  backward  but  little  further  than  the  first  peripheral.  While  portions  of  most  of 
the  neurals  remain,  little  regarding  them  can  be  said.  The  seventh  has  a  length  of  40 
mm.  The  eighth  is  small.  There  are  apparently  3  suprapygals.  Of  these  the  anterior 
appears  to  have  been  23  mm.  long  and  to  have  had  an  anterior  concave  and  a  posterior  convex 

border.  The  second  suprapygal  is  bifurcate,  with  the  lateral 
branches  resting  on  the  eleventh  peripheral.  The  third  supra- 
pygal is  lozenge-shaped  and  is  included  between  the  branches 
of  the  second  suprapygal  bone  and  the  pygal.  The  costals 
vary  considerably  in  width;  but  unlike  those  of  the  species  of 
Testudo,  the  upper  and  the  lower  ends  differ  little  in  width. 
The  table  herewith  gives  the  dimensions  of  the  costals,  excluding 
the  first. 

The  peripherals  are  large,  those  of  the  bridge  region  rising 
much  higher  than  in  H.  corsoni.  The  first  and  second  each 
occupy  about  80  mm.  of  the  free  border  of  the  carapace  and 
extend  backward  from  the  border  72  mm.  Those  of  the  bridge  region  rise  a  distance  of 
90  mm.  above  the  slight  carina  which  runs  from  the  free  edge  of  the  third  peripheral  to  the 
edge  of  the  seventh.  The  eleventh  peripheral  rises  70  mm.  from  the  free  border.  The 
pygal  is  45  mm.  high  in  the  midline;  62  mm.  wide  at  the  upper  border;  and  40  mm.  wide 
at  the  lower  border.  The  upper  border  is  notcht  for  the  lower  border  of  the  hindermost 
suprapygal. 

The  sutures  between  the  bridge  peripherals  coincide  at  their  upper  ends  closely  with  those 
between  the  costals,  except  that  between  the  fourth  and  fifth  peripherals.  The  sutures  between 
the  bridge  peripherals  and  the  plastral  bones  appear  to  have  been  obliterated. 

The  sulci  between  the  dermal  scutes  of  the  carapace  are  narrow  and  shallow,  but  most  of 
them  lie  in  rather  deep  grooves  in  the  bones.  Of  the  vertebrals  none  can  be  satisfactorily  mapt, 
except  the  fifth.  This  is  about  150  mm.  wide  behind.  Its  anterior  border  appears  to  have 
crost  the  eighth  neural.  It  is  probable  that  the  others  were  narrow.  The  sulci  between  the 
costal  scutes  and  the  marginals  follow  closely  the  sutures  between  the  costal  and  the  peripheral 
bones,  except  that  in  front  the  sulci  lie  on  the  nuchal  and  the  first  and  second  peripheral 
bones;  while  in  the  rear  the  sulcus  crosses  from  side  to  side  the  hindermost  suprapygal.  There 
are  two  very  distinct  supracaudal  scutes,  a  right  and  a  left. 

The  total  length  of  the  plastron  (fig.  472)  was  about  that  of  the  carapace,  530  mm.  The 
anterior  lobe  extends  somewhat  in  front  of  the  anterior  border  of  the  carapace,  and  has  a  length 
of  180  mm.  The  width  was  at  least  266  mm.  There  is  a  rather  prominent  lip,  which  projects 
beyond  the  general  border  of  the  lobe.  This  lip  is  truncated,  or  only  slightly  rounded  in  front. 
The  width  at  the  base  is  120  mm.,  in  front  about  88  mm.  The  free  borders  of  the  lobe  are 
subacute,  but  the  front  of  the  lip  is  considerably  thickened.  On  the  upper  side  the  thicken- 
ing increases  until  it  is  33  mm.  There  is  on  this  upper  surface  a  median  ridge,  on  each  side 
of  which  is  a  longitudinal  valley. 


Costal. 

Width 
proiimally. 

Width 
distally. 

t 

62 

77 

3 

45 

5° 

4 

7^ 

70 

5 

46 

44 

6 

45 

45 

7 

3° 

40 

g 

35 

55 

Z7^ 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


The  entoplastron  appears  to  have  been  of  the  same  form  as  in  H .  corsont.  Its  length  is 
80  mm.,  its  width  120  mm.     The  length  of  the  bridge  is  206  mm. 

On  account  of  lateral  crushing  the  width  of  the  posterior  lobe  can  not  be  accurately 
determined.  Its  length  is  175  mm.  It  is  conspicuously  notcht  behind,  the  depth  of  the  notch 
being  45  mm. 

The  gular  scutes  probably  overlap  slightly  the  entoplastron,  but  this  is  not  certain.     The 

humero-pectoral  sulcus  skirts  the  hinder  border  of  the 
entoplastron.  The  pectoral  scutes  have  a  form  quite  differ- 
ent from  that  of  H.  corsoni.  They  are  narrow  just 
meslad  of  the  axillary  notch,  but  grow  wider  as  they 
approach  the  midline,  attaining  there  a  width  of  75  mm. 
At  the  midline  the  abdominals  have  a  fore-and-aft  extent 
of  140  mm.,  the  feniorals  80  mm.,  the  anals  about  55  mm. 
The  sulci  of  the  plastron  are  rather  narrow  and  shallow,  but 
those  of  the  bridge  lie  in  deep  grooves. 

This  species  differs  from  H .  corsoni  in  several  respects. 
The  most  conspicuous  is  perhaps  the  height  of  the  periph- 
erals, especially  those  above  the  bridges.  The  form  and 
width  of  the  pectoral  scutes  too  is  distinctive.  The  bridge 
appears  to  be  shorter  in  comparison  with  the  length  of 
the  anterior  lobe.  The  hinder  borders  of  the  carapace 
are  more  scallopt  than  in  H.  corsoni. 

Prof.  E.  D.  Cope  referred  some  remains  of  Hadri- 
anus  from  the  Wasatch  of  New  Mexico  to  H.  corsoni;  while 
other  remains  he  regarded  as  a  distinct  species,  which, 
however,  he  did  not  name.  His  specimens  appear  to  be 
lost.  It  is  doubtful  whether  any  of  them  belonged  to  the 
Bridger  species. 

Hadrianus  rnajusculus  is  interesting  because  of  the  fact  that  it  is  the  oldest-known  repre- 
sentative of  the  family  Testudinidae.  


472. — Hadrianus    majusculu 
Plastron  of  type.     X  J. 


Hadrianus  corsoni  (Leidy). 
Plates  60,  61;   text-figs.  473-479. 

Testudo  corsoni,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1871,  p.  154;  U.  S.  Geol.  Surv.  Montana,  etc., 

1872,  p.  366;   Proc.  Acad.  Nat.  Sci.  Phila.  1872,  p.  268;  Contrib.  Extinct  Vert.  Fauna  West.  Terrs., 

1873,  pp.  132,  339,  plate  xi,  figs,  i,  2;   plate  xv,  fig.  7;   plate  xxix,  figs.  2-4;  plate  xxx,  figs.  1-4. 
Emys  carteri,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1871,  p.  228;   Amer.  Jour.  Sci.,  (3)  11,  1871,  p.  372; 

U.  S.  Geol.  Surv.  Mont.,  etc.,  1872,  p.  367;   Contrib.  Ext.  Vert.  Fauna  West.  Terrs.,  1873,  pi.  xi. 

Testudo  hadrianus,  Cope,  Palaeont.  Bull.  No.  I,  1872;   Proc.  Amer.  Philos.  Soc,  xil,  1873,  p.  463. 

Hadrianus  quadratus,  CoPE,  Proc.  Amer.  l^hilos.  Soc,  xii,  1873,  p.  468. 

Hadrianus  octonarius,  CoPE,  Palaeont.  Bull.  No.  2,  1872;  Proc.  Amer.  Philos.  Soc,  xil,  1873,  P-  4^^! 
U.  S.  Geol.  Surv.  Terrs.,  6th.  Ann.  Rept.,  1872  (1873),  p.  630;  Amer.  Naturalist,  xvi,  1882,  p.  992, 
figs.  11-13;  Vert.  Tert.  Form.  West.  1884,  p.  140,  plate  xx,  figs.  1-4. — OsBORN,  Scott,  and  Speir, 
Pal.  Rept.  Princeton  Sci.  Exped.  1877,  p.  95. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902, p.  450. 

Hadrianus  corsoni,  CoPE,  U.  S.  Geol.  Surv.  Terrs.,  6th.  Ann.  Rept.,  1872  (1873),  p.  631;  .?Syst.  Cat. 
Vert.  Eocene  N.  Mex.,  1873,  P-  3^;  •''Ann.  Rept.  Chief  Engineers,  Explor.  W.  looth  Merid.,  1875, 
p.  1016  (of  separata,  p.  96);  .'Wheeler's  Rept.  U.  S.  Geog.  Surv.  W.  lOOth  Merid.,  iv,  1877,  p.  58, 
plate  xxiv,  figs.  36,  37;  Amer.  Naturalist,  xvi,  1882,  p.  992;  Vert.  Tert.  Form.  West,  1884,  p.  141. — 
Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  450;    Amer.  Geologist,  xxxv,   1905,  p.  333. 

This  species  was  based  on  the  anterior  portion  of  a  plastron  which  was  discovered  by  Dr. 
Corson  at  the  Grizzly  Buttes,  about  15  miles  south  of  east  of  Fort  Bridger,  Wyoming,  and 
which  was  sent  for  study  to  Dr.  Leidy.  This  was  figured  by  the  latter  author  in  his  Contribu- 
tions to  the  Extinct  Fauna  of  the  Western  Territories,  plate  xv,  fig.  7,  and  is  in  the  Academy 
of  Natural  Science,  at  Philadelphia.  In  1871  Dr.  Leidy  made  a  trip  to  Fort  Bridger  and 
obtained  a  number  of  specimens  of  the  same  species,  and  these  added  much  to  the  knowledge  of 
the  animal.  Among  the  remains  secured  was  a  large  plastron  which,  on  account  of  post- 
mortem injury  to  the  lip,  Dr.  Leidy  did  not  recognize  and  which  he  made  the  type  of  the  species 


TESTUDINIDjS. 


377 


Emys  carter!.  A  still  larger  and  nearly  complete  plastron  was  correctly  identified;  likewise 
a  portion  of  a  carapace  of  another  individual,  including  the  neurals  and  the  proximal  portions 
of  most  of  the  costals.  Some  of  the  materials  obtained  by  Dr.  Leidy  exemplify  the  great  varia- 
tion found  in  the  form  of  the  anterior  lip.  Professor  Cope  in  the  same  year,  1 87 1,  discovered 
several  specimens  which  he  recognized  as  belonging  to  Leidy's  species;  but  he  gave  no  extended 
description  and  no  figures.  Under  the  name  Hadrianus  octonarius  he  described  and  figured 
a  large  and  nearly  perfect  shell  which  is  now  in  the  U.  S.  National  Museum.  For  reasons 
given  below  this  is  referred  by  the  present  writer  to  H.  corsoni. 

Besides  the  specimens  described  by  Dr.  Leidy  and  Professor  Cope,  a  number  of  other  well- 
preserved  shells  have  been  discovered.     One  of  the  largest  of  these  is  now  in  the  museum  of 


473- 


474- 


475- 


Pigs.  473-475. — Hadrianus  corsoni.     Carapace  and  plastron.     X  J.     No.  6027  A.  M.  N.  H. 

473.  Carapace. 

474.  Rear  of  carapace,     c. /i.  7,  seventh  costal;  n.  8,  eighth  neural; 

spy,  I,  spy.  2,  first  and  second  suprapygals;  py,  third  suprapygal. 

475.  Plastron. 

Princeton  University,  and  will  be  referred  to  again.  During  the  summer  of  1903  the  American 
Museum  expedition  to  the  Bridger  Eocene,  in  the  region  east  of  Fort  Bridger,  collected  3 
more  or  less  complete  turtles  of  this  species.  One  of  these,  No.  6027,  furnishes  the  following 
description: 

The  plastron  is  almost  wholly  uninjured.  The  carapace  lacks  a  little  of  the  anterior  margin, 
some  portions  of  the  bridge  peripherals,  the  pygal,  a  part  of  the  eleventh  peripheral,  and  the 
right  peripherals  behind  the  axillary  notch,  except  the  tenth  and  a  part  of  the  eleventh.  The 
shell  appears  not  to  have  suffered  any  considerable  depression  during  fossilization. 

The  length  of  the  carapace  (plate  60;  text-fig.  473)  in  a  straight  line  from  the  front  to  the 
rear  is  590  mm.;  its  greatest  width  close  to  455  mm.;  its  greatest  height,  which  is  toward  the 
rear,  215  mm.  The  border  in  front  is  between  rounded  and  truncate;  behind,  the  outline  is 
broadly  rounded.    The  peripherals  over  the  limbs  are  slightly  flared;   the  pygal  region  seems 


37^ 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


to  have  sloped  steeply.    The  carapace  is  broadly  archt  along  the  median  line  and  more  sharply 
archt  from  side  to  side. 

The  nuchal  bone  occupied  too  mm.  of  the  free  border;  its  maximum  width  is  120  mm.; 
and  its  length  is  I  lo  mm.  The  neurals  agree  very  closely  with  those  of  Leidy's  plate  xxx,  fig.  I, 
of  his  Contributions.  Not  one  is  octagonal.  The  first  is  clavate;  the  second  is  hexagonal,  and 
comes  into  contact  with  both  the  second  and  the  third  pairs  of  costal  plates;  the  third  is  quad- 
rilateral and  in  contact  with  the  third  pair  of  costals  only.  The  succeeding  neurals  are  all  hex- 
agonal, and  each  is  in  contact  with  the  corresponding  pair  of  costals  and  with  the  pair 
immediately  in  front.  The  anterior  four  neurals  are  longer  than  broad;  the  posterior  four  are 
broader  than  long. 

Behind  the  neurals  is  a  series  of  3  suprapygals  (fig.  474).  The  first,  or  most  anterior,  is 
42  mm.  long  and  34  mm.  wide.  It  is  in  contact  with  the  eighth  pair  of  costals.  The  second 
suprapygal  is  bifurcate,  as  in  Testudo,  and  the  forks  rest  on  the  eleventh  peripherals.  The 
third  suprapygal  is  triangular,  with  a  straight  and  broad  base,  and  lies  between  the  forks  of 
the  second  suprapygal.  It  is  evident  that  there  were  three  suprapygals  in  the  specimen  repre- 
sented by  Leidy,  plate  xxx,  fig.  i,  of  his  Contributions,  etc. 

The  costals  display  only  the  earliest  stages  of  the  differentiation  seen  in  the  genus  Testudo. 
Only  those  of  the  third  pair  articulate  with  3  neurals.    The  table  herewith  presents  the  widths 

of  the  upper  and  lower  ends.  Most  of  the  costals  are  crost  by 
low  ridges,  which  mark  the  stages  of  growth  of  the  dermal  scutes. 
The  peripherals  are  relatively  low,  as  compared  with  those 
of  most  species  of  the  genus  Testudo.  Those  of  the  bridge  have 
a  height  of  about  80  mm.,  as  do  also  those  of  the  axillary  and 
inguinal  regions. 

The  vertebral  scutes  are  of  moderate  width  and  have 
straight  sides.  The  first,  second,  and  fourth  are  each  106  mm. 
wide;  the  third,  11 1  mm.;  the  fifth,  179  mm.  at  its  hinder 
end.  The  first  vertebral  is  80  mm.  wide  at  the  anterior  end. 
The  nuchal  scute  is  40  mm.  long  and  about  17  mm.  wide.  The 
sulcus  between  the  marginal  scutes  and  the  costals  follows  closely 
the  suture  between  the  underlying  bones,  except  that  it  crosses  the  first  peripheral  some  dis- 
tance below  its  upper  border. 

The  plastron  (plate  61;  text-fig.  475)  has  an  extreme  length  of  550  mm.  The  anterior  end 
projects  about  35  mm.  in  front  of  the  carapace.  The  central  parts  of  the  plastron  are  somewhat 
concave.  The  anterior  lobe  is  175  mm.  long  and  246  mm.  wide  at  the  base.  The  free  borders 
are  acute.  The  anterior  lip  projects  slightly  beyond  the  general  contour  of  the  lobe,  and  35  mm. 
beyond  the  line  joining  the  points  where  gulo-humeral  sulci  cross  the  free  border.  Between 
these  points  the  lip  is  1 18  mm.  wide.  On  its  superior  surface  the  lip  extends  backward  75  mm. 
The  upper  surface  is  slightly  convex  from  side  to  side;  the  lower  surface  is  nearly  flat.  The 
anterior  outline  is  rounded. 

The  entoplastron  is  narrow  in  front  and  broad  behind.  The  length  in  the  median  line  is 
1 15  mm.;  the  greatest  breadth,  134  mm. 

The  length  of  the  posterior  lobe  is  157  mm.;  the  width  at  the  base,  240  mm.  The  width 
of  the  posterior  notch  is  about  80  mm.;  the  depth,  30  mm.  The  fore-and-aft  extent  of  the 
bridge  is  215  mm.  The  free  edges  of  this  lobe  are  acute.  At  the  inguinal  notch  the  border  of 
the  hypoplastron  is  36  mm.  thick.  From  the  summit  of  the  wall  thus  formed  the  bone  slopes 
to  the  free  edge  at  an  angle  of  about  45°. 

The  gular  scutes  encroach  somewhat  on  the  entoplastron.  The  humero-pectoral  sulcus  is 
tangent  to  the  entoplastron  behind.  The  pectoral  scutes  meet  along  the  midline  about  62  mm.; 
the  abdominals,  163  mm.;  the  femorals,  73  mm.;  the  anals,  43  mm. 

A  specimen  in  the  American  Museum  of  Natural  History,  No.  1068,  belonging  to  the  Cope 
collection,  having  a  plastron  410  mm.  long,  agrees  well  with  the  preceding  description.  How- 
ever, the  anterior  vertebral  scute  is  urn-shaped,  with  an  anterior  width  of  44  mm.  and  a  pos- 
terior width  of  85  mm. 

Another  shell  obtained  by  the  American  Museum  expedition  of  1903,  No.  6026,  has  a 
length  of  700  mm.    The  carapace  is  badly  fractured  and  some  portions  of  it  are  missing.    The 


Costal. 

Width 

Width     ' 

upper  end. 

lower  end. 
78         I 

67 

65 

79 

78 

56 

74 

67 

63 

51 

44 

50 

7 

i7 

$(■ 

8 

1 

40 

7» 

TESTUDINID^. 


379 


sutures  are  so  fine  that  it  is  not  easy  to  trace  them.  The  nuchal  scute  is  extremely  narrow;  the 
supracaudal  is  divided  at  the  midline.  The  peripherals  over  the  limbs  are  considerably  flared, 
but  the  pygal  is  nearly  perpendicular.  The  plastron  is  more  concave  than  in  the  specimen  here 
first  described.  Also  the  lip  is  more  truncate  in  front.  The  pectoral  scutes  are  only  48  mm. 
wide  at  the  midline.  The  notch  in  the  hinder  end  of  the  plastron  is  150  mm.  wide  and  46  mm. 
deep;  being  thus  much  wider  than  in  the  specimen  here  first  described.  The  apices  on  each 
side  of  the  notch  are  rather  narrow  and  pointed. 

No.  5958  of  the  same  museum  was  collected  in  1903.  It  has  a  length  of  720  mm.  The 
plastral  lip  has  the  form  shown  in  the  figure  of  Cope's  H.  octonarius  (Vert.  Tert.  Form.  West, 
plate  xx),  having  parallel  sides  and  a  truncated  front.  The  notch  and  the  apices  also  resemble 
those  of  Cope's  H.  octonarius.  The  entoplastron  is  damaged,  so  that  its  form  can  not  be  deter- 
mined.   The  shell  is  considerably  crusht  laterally. 

No.  10082  of  the  Museum  at  Princeton  University  was  collected  at  Smith's  Fork,  in  south- 
western Wyoming,  in  1878.  It  has  been  regarded  as  being i^.  of/ow<7r7«j-.    Its  length  is  790  mm.; 


476fl. 


476/). 


478.  477- 

Figs.  476-479. — Hadrianus  corsoni.     X  i. 


479- 


476.  Scapula  and  coracoid.    No.  1068  A.M.N. H.    a,  seen  from  below;  6,  seen  from  in  front.    for,coracoid; 

ficor,  procoracoid  process;  scapy  scapula. 

477.  Pelvis  seen  from  below.    No.  1068  A.  M.  N.  H.     /7,  ilium;  r'jc/r,  ischium;  />w6,  pubis. 

478.  Pelvis  seen  from  left  side. 

479.  Right  ilium  of  large  individual.     No.  6026  A.  M.  N.  H. 

its  width,  635  mm.;  its  height,  305  mm.  The  shell  is  nearly  complete.  The  carapace  is  convex 
transversely  but  rather  flat  on  the  middle  line.  From  front  to  the  rear  it  is  convex  with  the 
pygal  region  quite  steep.  The  front  and  rear  are  somewhat  truncate.  All  the  peripherals 
are  acute-edged.  The  sutures  bounding  the  neurals  are  so  fine  that  they  have  not  been 
determined.  The  first  vertebral  scute  is  62  mm.  wide  in  front,  135  mm.  wide  behind,  thus 
differing  from  that  of  other  specimens  in  being  very  narrow  in  front.  The  second  is  135  mm. 
wide;  the  third,  144  mm.;  the  fourth,  163  mm.;  the  fifth,  270  mm.  The  nuchal  is  48  mm. 
long  and  36  mm.  wide. 

The  plastron  has  a  length  of  about  775  mm.  It  is  very  concave,  and  has  probably  been 
that  of  a  male.  The  lip  projects  about  80  mm.  beyond  the  front  of  the  carapace.  It  is  large 
and  of  rather  unusual  form.    The  width  at  the  base  is  1 13  mm.  but  it  expands  toward  the  front 


380  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

to  132  mm.  There  is  a  slight  notch  in  the  midline,  and  the  lateral  angles  are  rounded  off.  The 
notch  in  the  hinder  lobe  of  the  plastron  is  55  mm.  deep.  The  humero-pectoral  sulcus  falls 
about  18  mm.  behind  the  entoplastron.    The  pectoral  scutes  are  55  mm.  wide  at  the  midline. 

It  appears  to  the  present  writer  that  the  specimen  on  which  Professor  Cope  based  his  H. 
octonartus  belongs  really  to  H.  corsoni.  Cope  states  that  the  shell  "is  of  an  elongated  form, 
strongly  contracted  at  the  bridge,  but  expanded  and  arched  above  the  limbs.  "  This  narrowness 
of  the  fossil  is  deceptive,  having,  largely  at  least,  been  produced  by  distortion  during  fossiliza- 
tion.  The  right  side  is  crusht  inward  from  50  mm.  to  100  mm.  and  the  hyoplastron  and  hypo- 
plastron  of  one  side  have  been  pushed  so  as  to  overlap  those  of  the  other  side.  From  the  mesial 
border  of  the  left  hyoplastron  at  its  hinder  edge  to  the  left  outline  of  the  shell  is  about  260  mm., 
which  would  make  the  width  of  the  shell  about  520  mm.,  instead  of  437  mm.,  as  given  by  Cope. 
This  estimate  makes  the  shell  but  little  narrower  than  that  of  the  specimen  first  described  above, 
and  this  can  hardly  be  regarded  as  H.  octonarius.  Cope  has  also  stated  that  the  entoplastron 
is  heart-shaped;  but  this  is  an  error,  caused  by  not  carefully  distinguishing  fractures  from 
sutures.  Its  form  is  that  seen  in  H.  corsoni.  The  upper  surface  of  the  lip  is  concave,  whereas 
in  other  specimens  it  is  commonly  convex  or  flat. 

It  is  evident  that  there  are  great  variations  in  the  form  of  the  lip  and  likewise  in  the  size 
and  form  of  the  notch  in  the  hinder  lobe.  Furthermore  there  appears  to  be  no  unvarying 
association  of  a  large  lip  with  a  large  hinder  notch.  It  is  therefore  necessary  to  consider  the 
various  forms  as  belonging  to  a  single  species. 

Professor  Cope  identified  some  fragments  of  turtles  found  in  the  Wasatch  deposits  of  New 
Mexico,  on  Gallinas  River,  as  belonging  to  H .  corsoni.  It  is  more  probable  that  these  materials 
belonged  to  the  species  which  the  present  writer  has  named  HaJrianus  majusculus. 

Portions  of  the  internal  skeleton  of  this  species  are  rarely  found.  No  skull  has  yet  been 
secured.  No.  1068  of  the  American  Museum  of  Natural  History,  a  half-grown  individual  col- 
lected by  Cope,  furnishes  the  greater  part  of  both  scapulae,  both  coracoids,  both  ischia, 
both  pubes,  the  acetabular  end  of  one  ilium,  2  phalanges,  and  2  damaged  cervical  vertebrae. 

Fig.  476  represents  the  scapula  and  coracoid  of  the  left  side,  as  viewed  from  below;  it  also 
shows  the  left  scapula  as  seen  from  in  front.  It  will  be  observed  that  the  scapula  is  a  stout  bone, 
with  more  than  a  right  angle  between  the  body  of  the  bone  and  the  procoracoid  process.  Both 
the  body  and  the  process  are  comprest,  except  at  the  ends  distal  from  the  glenoid  process.  The 
coracoids  broaden  toward  the  mesial  border,  as  in  the  genus  Testudo. 

Fig.  477  presents  a  view  of  the  pelvis  from  below.  The  pelvis  resembles  more  that  of 
Testudo,  especially  that  of  T.  radiata  of  Madagascar,  than  that  of  any  of  the  Emydidae  at  the 
writer's  command.  The  lateral  process  of  the  pubis  is  placed  mostly  in  front  of  the  ischio- 
pubic  foramina.  The  section  of  the  process  is  nearly  circular  in  section.  From  the  hinder  border 
of  each  ischium  there  projects  a  pointed  process.  The  extremities  of  these  processes  are  distant 
from  each  other  more  than  half  the  distance  between  the  lower  borders  of  the  acetabula. 
In  fig.  478  the  pelvis  is  seen  from  the  left  side,  a  portion  of  the  ilium  being  missing.  Fig.  479 
shows  the  right  ilium  of  No.  6026  A.  M.  N.  H.  From  its  upper  end  there  projects  backward 
a  sharp  process,  which  received  the  outer  ends  of  the  two  hinder  sacral  ribs. 

The  radius  is  a  stout  bone.  All  the  bones  of  the  shoulder-girdle  and  pelvis  indicate  an 
animal  that  was  accustomed  to  bear  its  heavy  body  about  on  land. 

One  of  the  vertebrx  present  is  the  eighth  cervical.    It  resembles  closely  that  of  T .  radtata. 

Hadrianus  tumidus  sp.  nov. 

Fig.  480. 

The  specimen  on  which  this  species  reposes  was  obtained  in  the  upper  Uinta  deposits  of 
Utah,  by  the  American  Museum's  expedition  of  1895.  Its  number  is  6076.  It  consists  of 
nearly  the  whole  of  the  left  half  of  the  plastron  and  the  peripherals  above  the  bridge.  From 
the  plastron  are  missing  the  epiplastron  and  the  entoplastron.  The  parts  present  are  in  their 
natural  relations,  so  that  some  idea  may  be  obtained  of  the  appearance  of  the  shell. 

The  length  of  the  portion  of  the  plastron  present  (fig.  480),  from  the  anterior  end  of  the 
epiplastron  to  the  extremity  of  the  xiphiplastron,  is  533  mm.  The  whole  length  of  the  carapace 
could  then  have  been  hardly  less  than  800  mm.    The  breadth  of  the  half  plastron,  from  the 


TESTUDINIDj^. 


381 


midline  to  the  lower  ends  of  the  peripherals,  is  about  220  mm.  The  extreme  width  of  the  car- 
apace was  about  550  mm.  From  a  line  joining  the  axillary  and  inguinal  notches  the  bridge 
ascends  at  an  angle  of  30°,  altho  this  may  have  been  greater  during  life.  About  130  mm.  beyond 
the  line  mentioned  there  is  an  abrupt  turn  of  the  carapace  upward.  This  continues,  in  our 
specimen,  to  the  upper  margin  of  the  peripherals,  a  distance  of  135  mm.  The  abrupt  turn  men- 
tioned marks  the  position  of  a  sharp  carina  which  runs  along  the  side  of  the  shell  from  the  free 
border  of  the  carapace  in  front  of  the  bridge  to  the  free  border  behind  it.  Such  a  carina  is  seen 
in  at  least  some  specimens  o(  H.  corsonl.    The  width  of  the  bridge  is  250  mm. 

The  hinder  half  of  the  plastron  was  very  concave,  especially  from  the  inguinal  notches 
backward.    The  anterior  half  was  flat.    The  individual  was  probably  a  male. 

The  bone  of  the  central  portions  of  the  plastron  is  thin,  17  mm.  just  behind  the  ento- 
plastron,  in  the  midline;    9  mm.  at  the  suture  between  the  hyoplastrals  and  hypoplastrals; 

and  8  mm.  at  the  anterior  end  of  the  xiphiplastrals. 
Near  the  free  borders,  however,  the  bone  is  very 
thick,  31  mm.  at  the  anterior  end  of  the  epiplas- 
tron,  37  mm.  at  the  anterior  end  of  the  xiphiplas- 
tron.  On  the  epiplastron  the  bone  is  beveled  off 
gradually  to  a  sharp  edge.  Behind  the  inguinal 
notch  the  bone  is  beveled  off  very  abruptly,  so 
that  the  beveled  portion  is  nearly  perpendicular. 
The  hinder  end  of  the  xiphiplastron  is  32  mm. 
thick,  rough,  and  with  a  broad,  rounded  edge. 

No  part  of  the  entoplastron  is  present,  but 
the  sutural  border  of  the  epiplastron  enables  us 
to  determine  something  regarding  its  extent  and 
form.  It  had  a  breadth  of  156  mm.  at  the  hinder 
ends  of  the  epiplastrals.  From  a  line  joining 
these   it   has  extended  backward  about  75  mm. 

\^.,'-^^-\\        I         From  this  we  may  infer  that  its  larger  portion  lay 
,^~.J  V\__/         behind  the  ends  of  the  epiplastrals.      It  was  not 

crost  by  the  humero-pectoral  suture.  The  ante- 
rior end  of  the  hyoplastron,  where  it  articulated 
with  the  epiplastron,  is  55  mm.  wide.  The  extreme 
length  of  the  hyoplastron  is  222  mm.;  its  length 
in  the  midline  is  155  mm.  The  length  of  the 
hypoplastron  in  the  midline  is  140  mm.;  on  the 
line  joining  the  axillary  and  inguinal  notches,  173 
mm.  At  the  midline  the  xiphiplastrals  measure 
1 18  mm.  At  their  anterior  ends  they  are  140  mm. 
wide.  The  notch  at  the  posterior  end  of  the  plas- 
tron has  not  exceeded  25  mm.  in  depth. 

The  suture  between  the  plastron  and  the  per- 
ipheral bones,  on  the  bridge,  runs  a  very  sinuous 
course,  the  opposing  bones  forming  broad  inter- 
digitations  35  mm.  long.  The  fifth  and  sixth 
peripherals  are  each  about  85  mm.  wide,  fore  and  aft,  and  rise  about  135  mm.  above  the  turn 
of  the  carapace  upward. 

The  plastral  buttresses  of  this  species  are  rather  weak,  but  are  relatively  better  developt 
than  in  Testudo.  They  rise  to  the  upper  margin  of  the  peripherals.  The  sulci  are  deeply 
imprest.  The  humero-pectoral  begins  just  in  front  of  the  axillary  notch,  runs  inward  and  back- 
ward for  a  short  distance,  then  straight  across  the  plastron,  just  missing  the  hinder  border  of 
the  entoplastron.  Behind  this  sulcus,  55  mm.,  the  pectoro-abdominal  sulcus  crosses  the  mid- 
line. It  is  bent  slightly  forward  on  each  side,  then  runs  outward,  backward,  and  upward  to 
the  marginal  suture.  The  abdominal  scutes  have  great  extent.  Along  the  midline  they  measure 
193  mm.  The  sulcus  limiting  them  posteriorly  runs  from  the  midline  outward  and  somewhat 
foi-ward,  passing  50  mm.  in  front  of  the  inguinal  notch.     The  femoral  scutes  join  along  the 


Fig.  480. — Hadrianus  tumidus.  Plastron, 
lacking  epiplastron  and  entoplastron.  X  J. 
No.  2090  A.  M.  N.  H 


382  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

midline  for  the  space  of  85  mm.  The  sulcus  between  these  and  the  anals  is  directed  outward 
and  backward.  Where  it  crosses  the  edge  of  the  xiphiplastron  there  is  a  considerable  notch. 
The  anals  have  a  fore-and-aft  extent  of  about  70  mm.  and  a  breadth  of  103  mm.  each. 

The  sulcus  between  the  plastral  and  the  marginal  scutes  runs  above  the  lower  peripheral 
suture,  as  it  does  in  Testudo. 

There  is  a  large  inguinal  scute,  but  there  is  no  axillary  scute,  or  a  very  obscure  one. 

On  the  bridge  are  three  considerable  bosses,  separated  by  the  sulci  in  front  of  and  behind 
the  abdominal  scute. 

In  endeavoring  to  find  characters  to  distinguish  this  species  from  the  others  that  have  been 
described  we  miss  first  the  epiplastral  lip.  From  H.  majuscidus,  of  the  Wasatch,  it  differs  in 
having  the  bridge  longer  relatively  to  the  hinder  lobe.  In  the  Wasatch  species  the  hinder  lobe 
forms  about  85  per  cent,  of  the  length  of  the  bridge;  in  H.  tumidus,  only  about  •/■/  per  cent. 
The  pectoral  scute  of  H.  majusculus  is  broader  than  that  of  H.  tumidus,  and  the  anal  notch 
is  deeper. 

From  H.  corsoni,  of  the  Bridger  beds,  the  Uinta  species  appears  to  differ  in  several  respects. 
The  peripherals  over  the  bridges  are  evidently  higher,  the  height  in  the  former  species  amount- 
ing to  considerably  less  than  one-half  of  the  width  of  the  bridge,  while  in  the  Uinta  species  the 
height  is  equal  to  one-half  of  the  bridge.  In  H.  corsoni,  from  the  inguinal  buttress  a  broad 
ridge  runs  backward  to  the  rear  of  the  hinder  lobe  at  the  midline.  Mesiad  of  this,  the  upper 
side  of  the  plastron  is  concave,  especially  next  to  the  ridge.  Outside  of  the  ridge  the  surface  is 
beveled  off,  near  the  buttress  steeply,  but  less  and  less  so  more  posteriorly,  until  on  the  pos- 
terior outer  angle  of  the  xiphiplastron  the  slope  is  very  gentle.  In  H.  tumidus  this  ridge  is 
almost  wholly  obsolete  and  the  upper  surface  of  the  posterior  lobe  is  convex  to  near  the  border, 
then  pitches  off  nearly  perpendicularly.  This  condition  continues  to  the  notch  for  the  anal 
sulcus.  The  hinder  extremity  of  the  xiphiplastron  of//,  corsoni  is  thinned  off  to  a  sharp  edge 
while  in  //.  tumidus  it  is  thick  and  the  free  edge  is  rounded  off. 

Hadrianus?  schucherti  Hay. 

Text-fig.  481. 

Hadrianus  schucherti,  Hay,  Proc.  U.  S.  Nat.  Mus.,  xxii,  1899,  p.  22,  plates  iv,  v;  Bibliog.  and  Cat. 
Foss.  Vert.  N.  A.,  190?,  p.  450. — Schuchert,  Proc.  U.  S.  Nat.  Mus.,  xxiii,  1900,  p.  328. 

The  present  species  is  assigned  provisionally  to  the  genus  Hadrianus,  altho  it  belongs 
possibly  to  Testudo.  If  really  a  Testudo,  it  is  one  of  the  oldest,  if  not  the  oldest  of  the  genus, 
coming  as  it  does  from  the  Upper  Eocene. 

The  type  and  only  known  specimen  belongs  to  the  U.  S.  National  Museum.  It  was  dis- 
covered by  Prof.  Charles  Schuchert,  then  of  the  U.  S.  Geological  Survey,  in  the  Zeuglodon 
beds  of  the  Jackson  formation,  near  Cocoa  post-office,  in  Choctaw  County,  Alabama.  In  the 
immediate  vicinity  Professor  Schuchert  found  bones  of  the  mammals  Basilosaurus,  Dorudon, 
and  of  the  snake  Pterosphenus  schucherti  Lucas. 

The  upper  portion  of  the  carapace  of  this  specimen  had  been  eroded  away  down  to  the 
upper  borders  of  the  peripheral  bones.  We  are  therefore  unable  to  determine  the  characters 
of  the  neural  and  costal  bones.  Nor  are  we  able  to  determine  whether  the  supracaudal  scute 
was  single  or  double. 

The  total  length  of  the  carapace  was  originally  close  to  750  mm.  Its  width  is  525  mm.  As 
will  be  seen  from  an  inspection  of  fig.  481,  the  lateral  borders  of  the  shell  are  nearly  straight 
and  parallel  with  each  other.  In  front  of  the  axillary  notch  the  margins  round  rapidly  into  the 
anterior  border.  The  shell  is  quite  truncated  in  front.  The  hinder  border  approaches  in  form 
a  segment  of  a  circle.  Neither  the  anterior  nor  the  posterior  border  is  to  any  degree  serrated. 
The  peripherals  rise  on  the  sides  of  the  shell  to  a  height  of  100  mm.  The  passage  of  the  lower 
surface  of  the  shell  to  the  upper  is  quite  abrupt;  but  this  appears  to  be  due  to  a  considerable 
extent  to  distortion  by  pressure. 

The  borders  of  the  carapace  over  the  opening  for  the  hinder  limbs  are  flared  gently  upward; 
over  the  openings  for  the  forelimbs  they  are  more  strongly  flared. 

The  plastron  is  concave,  a  condition  that  indicates  a  male  individual.  It  has  a  length  of 
675  mm.    The  anterior  lobe  has  a  length  of  202  mm.  and  a  width  of  309  mm.    The  epiplastral 


TESTUDINID^. 


.^83 


lip  is  not  well  difFerentiated,  being  narrow,  pointed,  and  not  projecting  beyond  the  rim  of  the 
carapace.    The  extremity  is  considerably  thickened;    but  the  borders  are  rather  acute.    1  he 

entoplastron  has  a  width  of  150  mm.  Its 
hinder  border  can  not  be  exactly  traced,  but 
the  form  of  the  bone  has  apparently  been 
nearly  circular. 

The  bridge  has  a  width  of  281  mm.,  being 
therefore  a  little  more  than  four-tenths  of  the 
length  of  the  plastron. 

The  hinder  lobe  has  a  length  of  202  mm. 
Its  width  is  309  mm.  Its  dimensions  are  there- 
fore the  same  as  those  of  the  front  lobe.  The 
hinder  extremity  was  notcht,  but  the  angles 
on  each  side  of  the  notch  may  not  have  been 
so  acute  and  long  as  shown  in  the  restoration 
and  the  figure. 

The  arrangement  of  the  scutes  is  not,  so 

far  as  can  be   determined,  greatly   different 

from  that  of  other  Testudinidae.    The  gulars 

do  not   encroach  on  the  entoplastron.     The 

humero-pectoral  sulcus  runs  straight  across 

the  plastron  (not  touching  the  entoplastron) 

until  it  approaches  the  axillary  notches,  when 

it    turns    abruptly    forward.      The    pectoral 

scutes  are  very  narrow,  about  22  mm.  at  the 

midline,  but  they  widen  right  and  left.     The 

abdominal  scutes  extend  fore  and  aft  a  great 

,      ,      ■      ,„  distance,  about  242  mm.,  this  length   being 

Fig.  481. — Hadrianus  schuchertt.     I   astron.  X  it-           »   ■      j    •      »u      1        ..u     r  »u        1     ^          . 

^          ,,                  ■     TT  f  AT  ».  contamed  m  the  length  of  the  plastron  two 

from  type  in  U.  b.  N.  M.  ,       ,     ,r    •              t-V      r            1                 1 

"^  and  a  half  times.      1  he  femoral  scutes  have 

an  extent  of  56  mm.  along  the  midline.    There  were  evidently  inguinal  scutes;    but  no  axillary 

scutes  have  been  observed.     The  sulci  between  the  plastral  and  the  marginal  scutes  at  the 

bridges  appear  to  have  lain  on  the  plastral  bones,  near  the  sutures  between  the  plastral  and 

the  peripheral  bones. 

The  figure  publisht  in  the  Proceedings  of  the  U.  S.  National  Museum,  vol.  xxii,  plate  iv,  is 

eight  forty-fifths  the  size  of  the  original,  instead  of  one-seventh  as  stated  on  the  plate.     The 

diagrammatic  figure  forming  plate  v  of  that  publication  is  19  hundredths  the  natural  size. 

Genus  ACHILEMYS  nov. 

An  imperfectly  known  genus  of  the  Testudinidae.  Carapace  with  recurved  hinder  periph- 
erals. Sulcus  between  the  fifth  vertebral  scute  and  the  supracaudal  crossing,  as  in  Stylemys, 
on  the  last  suprapygal.  Plastron  with  a  broad,  extremely  short  lip,  which  is  obtuse  and  which 
does  not  thicken  backward  on  the  upper  surface  as  it  does  in  other  Testudinidae. 

Type:    Hadrianus  allahiatus  Cope. 

Achilemys  allabiata  (Cope). 
Figs.  482-485. 

Hadrianus  allahiatus,  CoPE,  Proc.  Amer.  Philos.  Soc,  xil,  1872,  p.  471;  6th  Ann.  Report  U.  S.  Geol. 
Surv.  Terrs.  (Hayden),  1872  (1873),  p.  630;  Vert.  Tert.  Form.  West,  1884,  p.  140,  plate  xv,  figs. 
13-15. — OsBORN,  Scott,  and  Speir,  Contrib.  Mus.  Geol.,  Archaeol.  Princeton  College,  No.  i,  1878, 
p.  94. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1903,  p.  450;    Amer.   Geologist,   xxxv,   1905, 

P-  333- 

The  type  of  the  present  species  belongs  to  the  U.  S.  National  Museum  and  bears  the 
number  4054.  It  consists  of  the  right  half  of  the  front  lobe  of  the  plastron,  2  anterior  periph- 
erals, 3  hinder  peripherals,  a  portion  of  the  pygal,  and  a  portion  of  the  last  suprapygal.    It 


384 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


was  obtained  by  Professor  Cope  in  the  neighborhood  of  Cottonwood  Creek,  Wyoming,  and 
comes  from  the  Bridget  Eocene  beds,  the  level  being  that  known  as  B. 

Cope's  description  of  this  species  is  very  brief  and  unsatisfactory,  not  even  doing  justice 
to  the  fragmentary  materials  at  his  command;  yet  including  statements  that  imply  that  he 
had  more  materials  than  are  now  accessible.  He  states  that  the  plastron  was  concave,  yet  we 
have  no  evidence  that  other  parts  of  it  were  present  than  the  half  of  the  anterior  lobe.  The 
surface  of  the  carapace  is  said  to  be  without  irregularities  of  surface,  yet  no  neurals  or  costals 
seem  to  have  been  secured. 

The  size  of  the  individual  must  have  been  greater  than  estimated  by  Cope.  He  says  that 
the  length  was  18  inches,  equal  to  437  mm.  Cope's  fig.  14  of  his  plate  represents  the  ninth, 
tenth,  and  eleventh  peripherals  of  the  right  side,  and  about  half  of  the  pygal.  The  length  of 
the  ninth  and  tenth  taken  together  amounts  to  156  mm.  The  length  of  the  same  two  elements 
of  a  specimen  of  H.  c or s on i  whose  carapace  has  a  length  of  590  mm.  is  131  mm.  An  estimate 
based  on  these  dimensions  makes  it  probable  that  the  type  of  the  species  had  a  length  of  about 
626  mm.,  or  about  25  inches. 

It  is  improbable  that  this  species  belongs  to  the  genus  Hadrianus.  Two  reasons  may  be 
assigned  for  this  opinion.     The  first  is  found  in  the  fact  that  there  is  no  epiplastral  lip,  a 


482.  483- 

Figs.  482-485. — Achilemys  allabiatus.     X  J.     Type. 

482.  Portion  of  rear  of  carapace,     per.  ii,  eleventh  peripheral;   py,  pygal;   spy,  suprapygal. 

483.  Portion  of  anterior  lobe  of  plastron,     hyo,  hyoplastron;   ent,  entoplastron;   epi,  epiplastron. 

484.  Section  of  ninth  peripheral. 

485.  Section  at  anterior  end  of  eleventh  peripheral. 

Structure  found  in  the  other  species  of  the  genus,  except  possibly  in  H.  tumidtts,  the  only  known 
specimen  of  which  does  not  present  that  region.  In  Achilemys  allabiata  this  lip  is  not  differ- 
entiated even  so  much  as  it  is  in  the  Emydidae. 

The  second  reason  is  found  in  the  structure  of  the  hinder  region  of  the  carapace.  With 
the  other  bones  of  this  species  at  Washington  there  is  a  portion  of  a  suprapygal  which  joins 
accurately  the  eleventh  peripheral  and  the  pygal  of  the  type.  This  is  represented  in  its  proper 
position  in  fig.  482.  This  bone  has  the  position  of  the  third  suprapygal  of  Testudo  and  of 
Hadrianus  corsoni.  In  the  genera  just  named  the  sulcus  between  the  last  vertebral  scute  and 
the  supracaudal  scute  follows  closely  the  suture  between  the  third  suprapygal  and  the  pygal. 
In  the  species  being  here  described  the  sulcus  crosses  the  suprapygal  at  some  distance  above 
the  suture  referred  to.  It  is  to  be  noted  also  that  the  three  peripherals  of  this  region  are 
traverst  by  perpendicular  sulci  from  top  to  free  border,  showing  that  the  sulcus  between  the 
marginal  scutes  and  the  costal  scutes  ran  on  or  above  the  sutures  between  the  peripheral  and 
costal  bones.  The  position  of  the  sulci  of  this  region  in  our  species  resembles  somewhat  that 
of  Kachuga,  as  represented  by  Mr.  Boulenger  (Cat.  Chelonians,  p.  53,  fig.  16). 

The  epiplastron  (fig.  483)  figured  by  Cope  has  the  anterior  end  thickened  and  rounded 
in  section.  More  posteriorly  this  epiplastron  has  an  acute  border.  At  their  symphysis  the  epi- 
plastra  have  a  thickness  of  23  mm.  The  truncated  end  of  the  anterior  lobe,  the  rudimentary 
lip,  has  a  width  of  about  125  mm.  The  scute-covered  area  on  the  upper  surface  is  18  mm. 
wide.  The  bone  on  this  surface  does  not  thin  backward  as  in  Testudo  and  Hadrianus.  The 
entoplastron  had  a  width  of  about  170  mm.     It  was  truncate  or  cordate  behind,  notwith- 


TESTUDINID^.  385 

standing  Cope's  statement.  Its  length  was  about  1 10  mm.  The  scutal  sulci  are  very  obscure 
on  this  fragment  of  the  plastron,  but  the  gulo-humeral  is  distinguishable. 

An  anterior  peripheral  has  the  upper  surface  nearly  flat  and  the  free  border  acute.  The 
hinder  peripherals  (fig.  482)  are  strongly  flared  upward  toward  the  free  border,  the  ninth  most 
so  (fig.  484),  the  eleventh  less  so  (fig.  485).  The  ninth  has  a  width  along  the  free  border  of 
85  mm.  and  the  height  was  about  90  mm.  in  a  straight  line.  All  the  peripherals  have  a  thick- 
ness of  about  18  mm.     The  pygal  is  21  mm.  thick. 

Cope  states  that  the  sulci  are  deeply  imprest.  Those  of  the  carapace  are  distinct  enough, 
but  those  of  the  front  of  the  carapace  are  very  narrow,  shallow,  and  indistinct.  The  gulo- 
humeral  sulcus  is  very  narrow  and  shallow  and  distinguisht  with  difficulty. 

Osborn,  Scott,  and  Speir's  identification  of  this  species  is  based  entirely  on  two  ungual 
phalanges  collected  by  them  in  the  Bridger  beds. 

Genus   STYLEMYS  Leidy. 

Testudinidae  with  the  plastron  joined  to  the  carapace  by  sutures,  and  with  inguinal 
buttresses  which  pass  a  short  distance  within  the  carapace  between  the  fifth  and  sixth  costal 
plates.  No  hinge  in  either  plastron  or  carapace.  Of  the  neural  plates,  those  behind  the  third 
are  hexagonal  and  have  the  antero-lateral  sides  much  the  shortest.  The  second  and  third  may 
be  hexagonal;  or  the  second  may  be  octagonal  and  the  third  tetragonal.  Two  or  three  supra- 
pygals;  the  penultimate,  bifurcate.  Ribs  at  distal  ends  of  costal  plates  entering  pits  in 
peripherals  of  bridges.  Costal  plates  with  opposite  ends  diff"ering  much  or  little  in  width. 
Epiplastral  lip  not  projecting  beyond  the  general  contour  of  the  anterior  lobe  of  plastron. 
Entoplastron  in  front  of  the  humero-pectoral  sulcus.  Supracaudal  scute  single.  Skull  and 
limbs,  so  far  as  known,  like  those  of  Gopherus. 

Type:     Stvlemys  nehrascensis  Leidy. 

The  relationship  of  this  genus  has  been  variously  regarded.  It  was  establisht  by  Leidy, 
the  name  being  given  through  a  misconception  that  the  plastral  buttresses  were  separate 
bones.  On  the  discovery  of  his  error  Dr.  Leidy  employed  for  a  while  the  name  Testudo  for 
the  species  of  this  genus,  while  in  his  latest  work  on  the  genus  (Contrib.  Ext.  Fauna  West. 
Terrs.)  he  vacillated  between  Testudo  and  Stylemys.  This  procedure  indicates  that  he  recog- 
nized the  close  relationships  between  the  species  with  which  he  was  dealing,  S.  nehrascensis, 
and  the  species  of  Testudo.  Professor  Cope  recognized  the  validity  of  the  genus.  While 
regarding  the  Emydidae  and  the  Testudinidae  as  forming  distinct  families,  he  referred  Stylemys 
to  the  former,  doubtless  supposing  that  the  digits  possest  three  phalanges  each. 

It  is  the  opinion  of  the  present  writer  that  the  genus  in  question  belongs  to  the  Testudinidae. 

Unfortunately,  we  are  even  yet  not  thoroly  acquainted  with  the  osteology  of  the  species 
of  Stylemys.  Probably  thousands  of  shells  of  S.  nehrascensis  have  been  observed,  yet  we  know 
of  only  one  skull  that  has  been  found  actually  associated  with  its  shell,  no  undisturbed  foot 
likewise  associated,  and  no  cervical  vertebrae  whatever.  In  the  collection  at  Princeton  Uni- 
versity there  is  the  greater  portion  of  a  skull  which  is  here  figured  as  belonging  to  S.  nehras- 
censis but  it  did  not  accompany  a  shell.  In  the  Carnegie  Museum  at  Pittsburg  is  a  shell  of 
5.  nehrascensis  accompanied  by  the  skull.  In  the  American  Museum  there  are  various  bones 
of  the  internal  skeleton  about  which  there  need  be  no  doubt.  All  the  indications  furnisht  by 
these  remains  point  to  a  close  relationship  with  our  living  land-tortoises.  The  skull  has  the 
structure  of  that  of  Gopherus  (Xerohates).  It  seems  quite  certain  that  none  of  the  digits 
possest  more  than  two  phalanges,  but  the  proof  is  not  complete.  The  scapula,  the  coracoid, 
the  humerus,  the  forearm  bones,  the  pelvis,  and  the  bones  of  the  hinder  limbs  agree  with  the 
corresponding  bones  of  Testudo  and  Gopherus.  A  humerus  of  5.  nehrascensis  (fig.  492)  shows 
that  the  radial  and  ulnar  processes  of  the  proximal  end  are  twisted  toward  each  other  as  in 
Testudo,  and  in  a  way  entirely  difl^erent  from  what  we  see  in  the  Emydidae.  The  form  and 
structure  of  the  shell  agree  rather  with  that  of  Testudo  than  with  that  of  the  Emydidae.  It  is 
true  that  in  the  type  species,  S.  nehrascensis,  the  neural  bones  and  the  costals  have  not  under- 
gone the  modifications  which  characterize  those  of  Testudo;  but  even  here  we  meet  with  the 
beginnings  of  these  modifications;  and  in  the  John  Day  species  they  become  unmistakable. 
Here  the  second  neural  is  octagonal,  the  third  is  tetragonal,  and  the  costals  have  become 
wedge-shaped.    A  peculiarity  of  the  hinder  region  of  the  carapace,  seen  rarely  in  the  Emydidae, 

25 


386  FOSSIL    TURTLES    OK    NORTH    AMERICA. 

presents  itself  in  Stylemys,  viz.,  a  bifurcate  penultimate  suprapygal.  The  nearest  approach  to 
this  is  seen  in  Kachuga  (Boulenger,  Cat.  Chelonians,  p.  53,  fig.  16). 

The  epiplastral  lip  of  Stylemys  does  not  project  forward  beyond  the  general  border  of  the 
plastron,  as  it  does  in  most  of  the  species  of  Testudo;  yet  the  epiplastral  bones  are  thickened 
anteriorly  on  the  upper  side  in  a  manner  similar  to  that  found  in  Testudo. 

The  geological  duration  of  the  genus,  so  far  as  known,  is  from  the  lower  Oreodon  beds  of 
the  White  River  deposits  to  the  John  Day  Miocene.  The  writer  has  not  been  able  to  find  any 
records  of  the  finding  of  specimens  of  the  genus  in  the  Titanotherium  beds.  It  is  remarkable 
that  the  genus  Hadrtanus  should  disappear  in  the  Uinta  deposits,  while  Stylemys  and  Testudo 
should  appear  immediately  afterwards  in  the  White  River  beds. 

The  writer  has  elsewhere  (Amer.  Geologist,  xxxv,  1905,  p.  342)  exprest  the  opinion  that 
the  living  North  American  species  included  under  the  name  Gopherus  (Xerobates  Agassiz) 
have  descended,  not  from  Hadrtanus,  but  rather  from  Stylemys.  This  opinion  is  based 
principally  on  the  fact  that  the  species  of  both  groups  have  a  longitudinal  ridge  along  the 
midline  of  the  triturating  surface  of  the  upper  jaw.  This  idea  requires  the  confirmation  to  be 
obtained  onl\'  in  the  discovery  of  more  complete  skeletons. 

Analysis  of  Spkcies  of  Stylemys. 

1.  Shell  nearly  as  broad  as  long.    Seldom  an  octagonal  neural  present.      Pectoral  scute,  on 

midline,  three-tenths  width  of  abdominals;  free  borders  of  hinder  peripherals  acute.  .   nehrascensis 

2.  Shell  nearly  as  broad  as  long.     Second  neural  octagonal,  third  quadrangular;   pectoral 

scutes  one-fifth  width  of  abdominals;    hinder  peripherals  obtuse capax 

3.  Shell  more  elongate;   neurals  as  in  capax;   peripherals  more  as  in  nehrascensis conspecta 

4.  Not  well  known.    Third  neural  4-sided;  anterior  lobe  truncated  in  front calaverensts 

Stylemys  nehrascensis  Leidy. 

Plate  59,  figs.  2-4;   plate  62,  figs,  i,  2;    text-figs.  486-496. 

Stylemys  nehrascensis,  Lkidy,  Proc.  Acad.  Nat.  Sci.  Phila.,  v,  1851,  p.  172;  Ann.  Rept.  U.  S.  Geol.  Surv. 

Wyoming,  etc.,  1870  (1871),  p.  366;  Contrib.  Ext.  Fauna  West.  Terrs.,  1873,  P-  2^+- — Cope,  Trans. 

Amer.  Philos.  Soc,  xiv,  p.  124,  plate  vii,  figs.  10-12;  Vert.  Tert.  P'orm.  West,  1884,  p.  769;  Contrib. 

Canad.  Palaeont.,  iii,  1891,  p.  5. — Lydekker,  Proc.  Zool.  Soc.  Lond.,  i88g,  p.  94. — Hay,  Bibliog. 

and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  450;  Ann.  Carnegie  Mus.,  iv,  1906  (1907),  p.  19,  figs.  9-1 1. 
Emys  hemispherica,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.,  v,  1851,  p.  173;    6th  Ann.  Rept.  Smithson. 

Inst.,  1851   (1852),  p.  65. 
Testudo  lata,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.,  v,  1851,  p.  173;  6th  Ann.  Rept.  Smithson.   Inst.  1851 

(1852),  p.  65;  Owen's  Rept.  on  Geol.  Surv.  Wis.,  Iowa,  and  Minn.,  1852,  p.  572;   Ancient  Fauna 

Nebraska,  in  Smithson.  Contrib.  Knowl.,  vi,  1854,  art.  vii,  pp.  no,  115,  plate  xxiii,  figs.  I,  2,  plate 

xxiv,  fig.  I. — Maack,  Pala;ontogr.,  xviii,  1869,  p.  246. 
Emys  oweni,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.,  v,  1851,  p.  327. 
Emys  culbertsontt,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.,  vi,  1852,  p.  34. 
Testudo  hemispherica,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1852,  vi,  p.  59;  Owens'  Rept.  on  Geol.  Surv. 

Wis.,  Iowa,  and  Minn.,  1852,  p.  570,  plate  xiie,  figs.  I,  2;   Ancient  Fauna  Neb.  1854,  pp.  105,  1 15, 

plate  XX,  figs.   I,  2,  plate  xxiv,  fig.  3. — Winckler,  Arch.  Mus.  Teyler,  11,   1869,  p.   146,  plates 

xxxi-xxxiii. — Maack.  Palaeontogr.,  xviii,  i86g,  p.  245. 
Testudo  nehrascensis,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.,  vi,  1852,  p.  59;  Owen's  Rept.  on  Geol.  Surv. 

Wis.,  Iowa,  and  Minn.,  1852,  p.  567,  plate  xiiA,  figs.  I,  2;  Ancient  Fauna  Neb.,  pp.  103,  115,  plate 

xix,  figs.  1-3;  Jour.  Acad.  Nat.  Sci.  Phila.,  (2),  vii,  1869,  p.  26  {Testudo,  or  Stylemys  neb.);    Contrib. 

Ext.  Fauna  West.  Terrs.,  1873,  p.  339,  plate  xix,  figs.  7,  9,  10 — Maack,  Palseontogr.,  xviii,  1869, 

p.  245. — Marsh,  Amer.  Jour.  Sci.,  (2),  l,  1870,  p.  292. — Zittel,  K.  A.,  Handbuch  Palaeont.,  ill, 

1889,  p.  540,  fig.  501. 
Testudo  oweni,  Leidy,  Proc.  Acad.  Nat.  Sci.   Phila.,  vi,   1852,  p.  59;    Owen's  Rept.  on  Geol.  Surv. 

Wis.,  Iowa,  and  Minn.,  1852,  p.  568,  plate  xiiA,  figs.  3,  4;  Ancient  Fauna  Neb.,  1854,  pp.  106,  115, 

plate  xxi,  figs,  i,  2,  plate  xxiv,  fig.  4. — Maack,  Palaeontogr.,  xviii,  1869,  p.  245. 
Testudo  culbertsonii,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.,  vi,  1852,  p.  59;  Owen's  Rept.  on  Geol.  Surv. 

Wis.,  Iowa,  and  Minn.,  1852,  pp.  569,  plate  xii,  figs.  1,2;  Ancient  Fauna  Neb.,  1854,  pp.  108,  115, 

plate  xxii,  figs.,  i,  2,  plate  xxiv,  fig.  2. — Maack,  Palaeontogr.,  xviii,  1869,  p.  246. — Haberlandt, 

Jahrb.  k.  k.  Reichsanst.,  xxvi,  1876,  p.  243. 
Emys  nehrascensis,  Leidy,  6th  Ann.  Rept.  Smithson.  Inst.,  1851  (1852),  p.  65. 
Emys  lata,  Leidy,  6th  Ann.  Rept.  Smithson.  Inst.,  1851  (1852),  p.  65 
Stylemys  citlhertsonii,  CoPE,  Trans.  Amer.  Philos.  Soc,  xiv,  1869,  p.  124. 


TESTUDINID^.  387 

This  species  is  by  far  the  most  abundant  fossil  turtle  found  in  any  of  the  geological  for- 
mations in  North  America.  Many  years  ago  Dr.  Leidy  stated  that  he  had  seen  hundreds  of 
the  shells;  and  since  that  time  many  in  addition  have  been  collected  and  deposited  in  the 
various  museums.  Some  individuals  attained  a  large  size.  Most  of  the  specimens  seen  in 
museums  are  of  small  or  moderate  size,  for  the  large  shells  have  not  usually  been  regarded  by 
collectors  as  worth  the  trouble  and  expense  of  transporting.  Statements  made  by  reliable 
collectors  are  to  the  effect  that  individuals  are  sometimes  met  with  which  have  had  a  length  of 
3  feet  (890  mm.)  The  type  of  Leidy's  Testudo  lata  had  a  plastron  21  inches  (about  530  mm.) 
long.  The  largest  shell  in  the  American  Museum  of  Natural  History  is  510  mm.  long,  375  mm. 
wide,  and  265  mm.  high. 

The  species  was  described  in  early  days  by  Leidy  under  several  specific  names,  which  are 
mentioned  in  the  synonymy.  These  so-called  species  were  based  in  some  cases  on  purely 
individual  characters;  in  others,  on  modifications  of  form  due  to  distortion.  Dr.  Leidy  him- 
self was  the  first  to  correct  these  errors.  The  specimens  from  which  were  drawn  the  following 
figures  publisht  by  Leidy  in  vol.  vi  of  the  Smithsonian  Contributions  to  Knowledge  are  in  the 
U.  S.  National  Museum:  Plate  xix,  figs,  i,  2,  3  {Testudo  nehrascensis);  plate  xx,  figs.  I,  2 
{T.  hemispherica);  plate  xxi,  figs.  I,  2  (T .  oweni).  The  specimens  from  which  were  obtained 
the  figures  of  T.  lata,  op.  cit.,  plate  xxiii,  plate  xxiv,  fig.  I,  are  in  the  Philadelphia  Academy. 

In  form  this  tortoise  was  broad  and  rather  high  and  vaulted.  The  height  and  convexity 
appear  to  have  increast  with  age.  Often  the  rather  low  and  flattened  form  is  due  to  pressure 
exerted  during  fossilization.  Nevertheless,  among  specimens  of  the  same  size  there  are 
difl^erences  in  the  form  and  height  of  the  shell  which  must  have  existed  during  the  life  of  the 
animals. 

The  width  of  the  shell  forms  about  85  per  cent,  of  the  total  length.  In  outline  the  carapace 
is  truncated  in  front,  or  even  a  little  concave;  behind,  it  is  broadly  rounded.  The  peripherals 
over  the  bridges  are  nearly  or  quite  perpendicular;  those  over  the  limbs  are  slightly  flared; 
those  in  front  slope  downward  and  forward,  or  flare  slightly  upward;  the  pygal  is  nearly 
perpendicular.  The  free  edges  of  the  anterior  and  posterior  peripherals,  the  nuchal,  and  the 
pygal  are  acute.  The  neurals,  excepting  the  first,  which  is  oval,  are  almost  always  hexagonal, 
with  the  two  shortest  sides  directed  forward.  Occasionally,  as  in  the  type  of  Leidy's  T. 
culbertsoni,  the  second  neural  is  octagonal,  the  third  quadrangular  (Ancient  Fauna  Neb., 
plate  xxii,  fig.  i).  There  are  usually  2  suprapygals,  the  larger  anterior  of  which  is  bifurcated, 
as  in  Testudo;  the  smaller  posterior  one  is  rhombic,  with  its  lower  border  fitting  in  a  notch  in  the 
upper  border  of  the  pygal.  In  Leidy's  type  just  referred  to  there  is  an  accessory  plate  in  front 
of  the  first  suprapygal;    and  the  same  condition  is  occasionally  met  with  in  other  specimens. 

The  costal  plates  are  modified  somewhat  as  they  are  in  the  genus  Testudo.  The  second, 
fourth,  and  sixth  are  somewhat  widened  distally  and  narrowed  proximally,  while  the  third 
and  fifth  are  narrowed  at  the  distal  end  and  widened  at  the  proximal.  The  degree  of  this 
difl^erentiation  varies  somewhat  with  individuals,  and  in  general  is  not  so  much  developt  as  in 
S.  conspecta  and  S.  capax.  In  uncrusht  examples  of  the  species  the  bridge  peripherals  rise 
nearly  half  the  height  of  the  shell.  In  a  specimen  whose  length  of  carapace  is  260  mm.  the 
height  of  these  peripherals  is  58  mm.  The  suture  between  the  costals  and  the  peripherals  is  a 
very  loose  one,  as  in  Testudo. 

The  sulci  bounding  the  carapacial  scutes  are  narrow,  but  rather  deeply  imprest.  The 
nuchal  scute  is  very  narrow.  The  first  vertebral  is  wider  by  one-half  than  the  second.  The 
fourth  is  somewhat  narrower  than  the  second  and  the  third;  while  the  fifth  is  nearly  as  wide 
as  the  first.  On  the  bridge  peripherals  the  sulci  run  obliquely  downward  and  forward.  The 
sulci  between  the  costal  scutes  and  the  marginals  follow  closely  the  sutures  between  the 
costal  and  peripheral  bones.     On  the  hinder  pygal  the  sulcus  runs  slightly  above  the  suture. 

The  anterior  lip  of  the  plastron  projects  little,  if  any,  beyond  the  general  curve  of  the 
anterior  lobe.  The  outline  of  the  lip  is  rounded  or  repand,  and  the  edge  is  rather  acute. 
Superiorly  the  lip  thickens  backward  for  a  distance  about  equal  to  the  width  of  a  gular  scute, 
and  then  ceases  abruptly,  but  there  is  no  excavation  behind  it.  The  entoplastron  is  narrow 
in  front  and  broad  behind.  The  width  of  the  bridges  is  not  quite  one-half  the  length  of  the 
plastron.  The  lobes  are  so  wide  that  space  is  left  only  for  the  movement  of  the  limbs  and  for 
the  tail.    There  is  a  notch  in  the  hinder  border  of  the  plastron,  and  the  apices  of  the  xiphi- 


388 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


plastia  on  each  side  of  this  are  rounded.  The  bone  of  the  plastron  is  relatively  thick.  In  the 
case  of  a  specimen  whose  plastron  is  210  mm.  long  the  thickness  of  the  hyoplastron  is  16  mm.; 
that  of  the  hypoplastron  half-way  between  the  median  line  and  the  inguinal  notch  is  14  mm. 
Proceeding  backward  from  the  inguinal  notch  near  the  free  border  there  is  a  low  wall  from  the 
summit  of  which  the  bone  slopes  downward  and  outward.  Farther  backward  the  height  of 
the  wall  diminishes  rapidly  and  the  slope  is  less  steep,  so  that  on  the  apices  of  the  xiphiplastra 
the  sloping  face  looks  nearly  upward.  From  the  summit  of  the  wall  the  surface  slopes  very 
slowly  toward  the  midline. 

The  gular  scutes  overlap  slightly  the  entoplastron.     The  humero-pectoral  sulcus  crosses 
the  midline  just  behind  the  entoplastron.    The  pectoral  scutes  are  rather  narrow  at  the  mid- 


486. 


'\    487- 


Figs.  486  and  487. — Styhmys  nehrascensis.     X  J. 
486.   Carapace.  487.   Plastron. 

line.  The  abdominals  are  the  widest  of  the  plastral  scutes.  At  the  midline  the  femorals  are 
about  as  wide  as  the  pectorals.  The  anals  occupy  somewhat  more  of  the  midline  than  do  the 
femorals.     Small  axillary  and  inguinal  scutes  are  present. 

Figs.  I  and  2  of  plate  62  furnish  illustrations  of  the  shell  of  a  specimen  of  the  species,  No. 
1433  of  the  American  Museum  of  Natural  History.  The  figures  are  half  the  natural  size. 
Text-figs.  486  and  487  are  derived  from  the  same  specimen. 

It  is  remarkable  that,  notwithstanding  the  great  number  of  individuals  of  this  species  which 
have  been  found,  few  skulls  have  hitherto  been  discovered.  Leidy,  writing  many  years  ago, 
stated  that  he  had  seen  hundreds  of  shells  but  no  skull.  The  one  here  described  as  probably 
belonging  to  this  species  belongs  to  Princeton  University. 

This  specimen  (plate  59,  figs.  2,  3)  was  collected  by  Mr.  J.  W.  Gidley,  now  of  the  U.  S. 
National  Museum,  in  the  year  1896.  It  was  found  in  the  Oreodon  beds  of  the  Hat  Creek 
Basin,  near  Prairie  Dog  Creek,  Nebraska.  It  was  not  accompanied  by  any  other  parts;  but 
in  the  White  River  deposits  of  that  region  Stylemys  nehrascensis  is  abundant;  and  no  other 
related  species,  except  one  specimen  of  Testudo  brontops,  of  the  Titanotherium  beds  and  T . 
thomsoni  of  the  lower  Oreodon  beds  has  been  found  in  the  White  River  Oligocene;  so  that  the 
probability  is  very  great  that  the  skull  belongs  to  this  species.  This  probability  is  confirmed 
by  the  skull  next  to  be  described. 

Unfortunately,  the  Princeton  skull  is  not  complete.  The  hinder  segment  is  missing,  as 
well  as  the  quadrates.  There  is  likewise  no  lower  jaw  present,  and  there  are  some  minor 
deficiencies, 


TESTUDINID^. 


389 


In  general  the  structure  of  the  skull  resembles  that  of  the  genus  Gopherus,  and  therefore 
in  general  that  of  Tesludo.  As  regards  its  size,  in  case  the  ratio  of  the  portion  behind  the 
orbits  to  that  from  the  postfrontal  bones  to  the  tip  of  the  snout  was  the  same  as  in  the  skull  of 
either  Gopherus  polyphemus  or  of  TestuJo  tabidata,  the  whole  length  from  snout  to  occipital 
condyle  must  have  been  about  75  mm.,  and  the  breadth  at  the  quadrates  about  61  mm.  The 
orbits  are  large,  about  20  mm.,  hardly  smaller  proportionately  than  they  are  in  the  Testudo 
mentioned.  The  interorbital  space  is  15  mm.  wide.  The  upper  surface  of  the  skull,  from  the 
nostrils  to  near  the  hinder  border  of  the  frontals,  is  gently  convex.  The  parietals  are  more 
convex  both  longitudinally  and  transversely. 

The  sides  of  the  face  just  behind  the  nostrils  were  nearly  perpendicular.  The  nasal 
opening  is  nearly  quadrate,  and  was  16  mm.  wide  and  about  10  mm.  high.  The  cutting- 
edges  of  the  maxillaries  make  about  the  same  angle  with  each  other  that  they  do  in  T.  tabulata 
and  G.  polyphemus.  There  is  a  broad  notch  in  the  cutting-edge  at  the  premaxillary  symphysis; 
and  behind  this  on  each  side  there  is  an  indication  of  a  tooth.  The  masticatory  surfaces  of 
the  upper  jaws  resemble  in  breadth  those  of  the  genus  Gopherus.    Along  the  middle  of  each 


489.  490. 

Figs.  488-492. — Stylemys  nehrascensis.     Skull   and  humeru.s. 

488.  Upper  view  of  skull.     Xi.     No.  1571  Carnegie  Museum. 

489.  Lower  view  of  same.     Xi. 

490.  Side  view  of  same.     Xi. 

491.  Right  humerus,  dorsal  view.     X§.    No.  700  A.  M.  N.  H. 

492.  Right  humerus,  proximal  end.    X§. 

surface  there  is  a  tootht  ridge  which  runs  parallel  with  the  cutting-edge.  In  front,  a  longi- 
tudinal ridge  runs  backward  from  the  symphysis,  as  in  G.  polyphemus,  a  character  which  has 
led  to  the  separation  of  the  North  American  species  of  Testudo,  to  form  the  genus  Gopherus. 
In  Stylemys  a  less  elevated  ridge  is  developt  on  the  inner  border  of  the  maxillary.  The  structure 
of  the  upper  jaw  is  like  that  of  Gopherus  polyphemus,  except  that  in  Stylemys  the  masticatory 
ridges  do  not  join  the  longitudinal  ridge. 

As  in  Testudo  and  Gopherus,  the  palate  is  archt  upward  high  above  the  level  of  the 
masticatory  surfaces;  and  there  is  a  sharp  ridge  which,  starting  on  the  vomer,  is  continued 
backward  to  the  hinder  end  of  the  latter  bone  and  on  the  conjoined  edges  of  the  pterygoids. 
The  width  of  the  vomer,  where  it  articulates  with  the  premaxillaries  and  the  maxillaries,  is 
considerable,  as  it  is  also  in  G.  polyphemus.  In  T.  tabulata  the  vomer  is  narrow  anteriorly  and 
articulates  only  slightly  with  the  maxillaries. 

The  vaulted  roof  of  the  mouth  continues  backward  as  far  as  the  bones  of  the  skull  are 
preserved,  and  judging  from  Testudo,  to  a  line  joining  the  front  borders  of  the  articular  ends 
of  the  quadrates.  In  the  specimen  the  vaulted  roof  has  been  forced  upward  and  broken  across 
the  middle,  and  a  portion  of  it  is  missing;  but  the  hinder  end  of  the  vomer  is  present,  and 
extended  backward  about  25  mm.  from  the  anterior  end.  The  palatines  extend  backward 
as  far  as  the  hinder  end  of  the  vomer.  The  nasopalatine  and  posterior  palatine  foramina  have 
the  same  positions  as  in  Gopherus.    The  former  is  rather  small. 

The  postfrontal  and  jugal  bones  are  missing;  as  are  also  the  prootics,  squamosals,  and 
quadrates. 


JyO  KOSSII.    TURTl.KS    OK    NORTH    AMKRICA. 

No.  1571  of  the  Carnegie  Museum,  Pittsburg,  furnishes  a  nearly  complete  skull  of  a  small 
individual  (text-figs.  488,  489,  490).  This  skull  is  accompanied  by  enough  of  the  shell  to 
establish  clearly  the  species.  The  remains  were  collected  in  1905,  by  Mr.  Earl  Douglass,  of 
the  Carnegie  Museum,  in  the  Oreodon  beds  of  the  Little  Badlands,  southwest  of  Dickinson, 
Stark  County,  North  Dakota.  So  far  as  the  parts  presented  by  this  skull  and  that  belonging 
to  Princeton  University  are  common,  they  agree  closely.  The  length  of  the  skull,  from  the 
snout  to  the  occipital  condyle,  is  38  mm.;  the  width  at  the  quadrates,  30  mm.  The  hinder 
border  of  the  postorbital  bar  is  equally  distant  from  the  occipital  condyle  and  the  snout.  The 
bar  just  mentioned  is  5  mm.  wide;  the  zygomatic  bar  is  slightly  wider.  The  interorbital 
space  is  10.5  mm.  wide.  The  antero-posterior  diameter  of  the  orbit  is  11  mm.;  the  vertical, 
9  mm.  The  longest  diameter  of  the  auditory  chamber  is  9  mm.  The  pterygoid  region  is  10 
mm.  wide.     The  pedicel  of  the  quadrate  is  unusually  narrow,  only  4  mm.  from  side  to  side. 

The  palate  is  deeply  excavated,  and  a  low  sharp  ridge  runs  along  the  middle  of  it.  Most 
of  the  lower  jaw  is  firmly  held  in  its  natural  position;  but  the  removal  of  the  tip  exposes  a  low 
median  ridge  along  the  palatal  part  of  the  symphysis  of  the  premaxillae.  It  is  evident  therefore 
that  the  larger  skull  described  above  is  correctly  identified. 

Few  satisfactory  specimens  of  the  bones  constituting  the  shoulder-girdle  of  adult  individ- 
uals have  been  secured.  In  the  American  Museum  these  bones  belonging  to  a  young  animal 
(No.  699,  from  South  Dakota)  are  present.  The  scapula  is  slender  and  makes  an  angle  of  about 
120  degrees  with  the  procoracoid  process.    The  coracoid  broadens  greatly  toward  the  free  end. 

No  figure  of  the  humerus  has  hitherto  been  publisht.  Professor  Cope  (Ext.  Bat.,  Rept, 
Aves  N.  A.,  1869,  plate  vii,  figs.  12,  1 2a)  presents  a  figure  which  is  explained  as  being  that  of 
the  humerus  of  this  species;  but  the  figure  is  that  of  the  femur.  The  humerus  of  the  specimen 
mentioned  above.  No.  699  of  the  American  Museum,  shows  that  the  bone  had  nearly  the  form 
that  it  has  in  G.  polyphemus,  but  it  is  bent  slightly  more  than  in  the  species  just  named.  Other 
larger  but  imperfect  specimens  confirm  this  conclusion.  Fig.  491  is  taken  from  one  of  these. 
No.  700,  American  Museum,  but  a  portion  of  the  shaft  is  inissing.  This  specimen  was  found 
with  the  shell.  Figure  492  is  a  view  taken  from  the  proximal  end,  to  show  the  head  and  the 
radial  and  ulnar  processes.  The  ulnar  process  does  not  rise  so  much  above  the  head  as  in 
Testudo  radtata.  The  angle  between  the  processes  is  reduced  as  in  Testudo  and  is  thus  different 
from  the  condition  found  in  the  Emydidae.  The  ectepicondylar  foramen  is  close  to  the  distal 
end  of  the  bone. 

The  Amerian  Museum  of  Natural  History  possesses  the  left  forearm  and  some  foot  bones 
of  a  large  specimen  believed  to  be  of  this  species.  No.  702,  collected  by  the  museum's  expedition 
of  1892,  in  South  Dakota.  A  drawing  (fig.  493)  is  presented  of  the  ulna,  radius,  intermedium, 
radiale,  the  ulnare,  the  fourth  distal  carpal,  and  another  (fig.  494)  of  a  digit,  including  one  claw 
phalange.  The  limb  is  stouter  than  it  is  in  any  of  the  species  of  Testudo  at  hand,  but  resembles 
them  closely.  The  proximal  end  of  the  ulna  is  broad,  and  forms  a  prominent  olecranon  process. 
The  distal  ends  of  both  radius  and  ulna  are  flat  for  articulation  with  the  carpals.  The  radius 
forms  a  prominent  styloid  process.  The  terminal  phalanges  are  much  larger  relatively  than 
they  are  in  most  species  of  Testudo,  but  approach  nearest  those  oiGopherus  polyphemus.  They 
differ  from  the  latter  in  not  being  so  broad  and  sharp-edged.  From  the  materials  at  hand  it 
can  not  be  determined  whether  there  were  two  or  three  phalanges  in  the  median  toes;  hut  no 
elongate  phalanges  are  present. 

There  are  at  hand  the  ilium  and  a  portion  of  the  pubis  of  a  specimen,  No.  1301,  from  Old 
Woman's  Creek,  Wyoming  (fig.  495).  On  comparison  with  the  corresponding  bones  of 
Testudo  vaga,  no  differences  of  importance  are  observed,  except  that  the  flat  process  extending 
backward  from  the  upper  end  of  the  ilium  is  directed  slightly  inward,  instead  of  outward. 
Cope  furnisht  a  figure  of  a  small  portion  of  the  pelvis  (Ext.  Batrach,  Rept.,  Aves  N.  A.,  plate 
vii,  fig.  11). 

The  femur  is  like  that  of  Testudo  vaga,  except  that  the  pit  between  the  trochanters  is  not 
so  deep.  Cope's  figure  of  this  bone  has  been  referred  to  in  the  description  of  the  humerus. 
No.  1301,  A.  M.  N.  H.,  furnishes  this  bone  from  the  left  side  (fig.  496).  It  is  shown  two-thirds 
the  size  of  nature  in  fig.  496.  It  resembles  closely  the  corresponding  bone  of  Gopherus  poly- 
phemus but  the  lower  articular  surface  is  more  deeply  grooved  and  there  is  a  distinct  and 
sharp  ridge  separating  the  tibial  from  the  fibular  surface. 


TESTUDINID^. 


391 


The  tibia  is  a  stout  bone,  whose  form  may  be  learned  from  figure  497,  which  represents  the 
left  tibia  of  No.  1301,  just  mentioned.  It  is  a  much  stouter  bone  than  is  the  corresponding  bone 
in  Gopherus  polyphemus.  Its  length  is  seven-tenths  that  of  the  femur,  whereas  in  G.  poly- 
phemus  the  tibia  is  eight-tenths  the  length  of  the  femur. 

The  lower  end  of  the  fibula  is  quite  as  broad  as  that  of  the  tibia.  Professor  Cope  figured 
one  of  the  metatarsals  (Ext.  Batrach.,  Rept.,  Aves  N.  A.,  plate  vii,  fig.  10). 

In  a  collection  of  fossils,  including  some  vertebrates  purchased  by  the  American  Museum 
of  Natural  History  from  the  late  James  Hall,  there  are  several  eggs  which  are  regarded  as 
those  of  iS\  nehrascensis.  This  identification  rests  on  the  facts  that  these  eggs  were  collected  in 
the  White  River  deposits  of  Dakota,  in  which  great  numbers  of  this  species  occur  and  a  few 
other  species  of  tortoise  and  that  they  agree  closely  in  size  and  form  with  those  of  Gopherus 
polyphemus,  as  represented  by  Agassiz's  figure  (Contrib.  Nat.  Hist.  U.  S.,  ii,  plate  vii,  figs. 
28,  29).  These  eggs  appear  to  have  been  globular,  altho  now  shorter  along  one  axis,  a  condition 
doubtless  due  to  pressure.  The  diameter  along  all  the  axes, except  the  shorter,  is  47  mm.;  along 
the  shorter,  43  mm.     Fig.  4,  plate  59,  represents  one  of  these  eggs  four-fifths  the  natural  size. 

The  eggs  of  G.  polyphemus  figured  by  Agassiz  have  diameters  varying  from  40  mm.  to 
45  mm.,  the  axes  of  the  same  egg  being,  in  some  cases,  unequal. 


493.  495.  496.  497. 

Figs.  49^-497. — Stylemys  nehrnscensis. 

493.  Left  ulna,  railius,  and  three  carpal  bones;  palmar  surface.      XA.      No.  702 

A.M.N.H.     /«/,  intermedian;  r^^,  radius;    «/,  ulna;  u/n,  ulnare. 

494.  Digit,  dorsal  surface.     X  i.     No.  702  A.  M.  N.  H. 

495.  Pelvis,  left  side.      Xj.     No.  1301  A.  M.  N.  H.     //.ilium;   />uii,  pubi.s. 

496.  Left  femur,  tibial  border.     Xj.     No.  1301  A.  M.  N.  H. 

497.  Left  tibia,  dorsal  surface.     Xj.     No.  1501  A.  M.  N.  H. 

No.  1435  A.  M.  N.  H.  is  a  specimen  of  a  very  young  turtle  of  this  species  which  was  col- 
lected by  one  of  the  American  Museum's  expeditions  to  South  Dakota.  The  shell  is  nearly 
complete,  but  is  somewhat  deprest  by  the  weight  of  the  overlying  rocks.  The  total  length 
was  near  75  mm.,  the  breadth,  70  mm.  Altho  the  bones  are  loosely  connected,  there  are  no 
fontanels.  The  plastral  lip  is  relatively  broad,  and  in  the  middle  of  each  lateral  half  there  is  a 
notch.  The  free  borders  of  the  carapace  have  been  slightly  notcht  and  mucronated;  at  least, 
some  mucros  are  seen  on  the  hinder  peripherals. 

So  far  as  is  known  to  the  writer,  no  specimens  of  this  species  have  yet  been  found  in  the 
lowermost  division  of  the  Oligocene,  the  Titanotherium  beds.  They  are  most  abundant  in 
the  Oreodon  beds,  but  occur  in  the  Protoceras  beds  also.  The  species  is  extremely  abundant 
in  South  Dakota  and  is  found  also  in  Nebraska,  Colorado,  and  Wyoming.  In  the  Cope  col- 
lection in  the  American  Museum  are  specimens  that  were  collected  on  Old  Woman's  Creek. 
Wyoming,  by  J.  C.  Isaac,  in  1877.  Other  specimens  were  obtained  in  the  Oreodon  beds  of 
Logan  County,  Colorado,  by  one  of  the  expeditions  from  the  American  Museum  of  Natural 
History  in  1898. 


392 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


Stylemys  oregonensis  Leidy. 

Stylemys  oregonensis,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1871,  p.  248.— Cope,  Bull.  U.  S.  Geol.  Surv. 

Terrs.,  v,  1879,  p.  55. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  451. 
Testudo  oregonensis,  Leidy,  Contrib.  Ext.  Vert.  Fauna  West.  Terrs.,  18,  pp.  226,  340,  plate  xv,  fig.  10. 

In  the  year  1871,  as  cited  above.  Dr.  Leidy  proposed  the  name  Stylemys  oregonensis  for 
a  species  of  turtle  whose  former  existence  he  inferred  from  a  single  neural  plate,  supposed  then 
to  be  the  eighth,  sent  to  him  from  the  John  Day  deposits  of  Oregon,  the  more  exact  locality 
being  given  as  Crooked  River.  In  the  later  publication  cited  (1873)  the  specimen  is  figured  and 
briefly  described,  being  here  regarded  as  the  third  neural.  On  page  340  of  this  work  the  sus- 
picion is  exprest  that  the  species  is  identical  with  that  from  the  White  River  deposits,  Stylemys 
nehrascensis.  Professor  E.  D.  Cope  possest  in  his  collection  a  number  of  well-preserved 
specimens  of  a  turtle  from  the  John  Day  River  region;  and  these  he  regarded  as  identical  with 
that  described  by  Dr.  Leidy  and  with  5.  nehrascensis.  He  notes  various  differences,  but  he  did 
not  find  them  to  be  constant. 

Whatever  Leidy's  type  neural  may  be  it  is  not  the  third  neural  of  any  known  Oregon 
species  of  Stylemys,  his  type  being  hexagonal,  that  of  the  John  Day  species  of  Stylemys  being 
quadrangular.  It  is  more  probably  the  fifth  neural,  but  not  with  any  certainty  that  of  Stylemys. 
If  a  Stylemys,  it  may  belong  to  either  or  neither  of  the  two  species  recognized  below  by  the 
present  writer. 

Stylemys  capax  sp.  nov. 

Plates  60,  61;   text-figs.  498,  499. 

Stylemys  nehrascensis,  in  part,  Cope,  Vert.  Tert.  Form.  West,  1884,  p.  770,  "No.  2." 

The  specimen  which  furnishes  the  description  of  this  supposed  new  species  was  collected 
for  Professor  Cope  from  the  John  Day  beds  of  Oregon.  The  exact  locality  is  said  to  have  been 
the  "Cove,"  in  the  region  of  the  junction  of  the  North  Fork  and  South  Fork  of  the  John 
Day  River,  in  the  western  part  of  Grant  County.  The  level  is  doubtless  the  Middle  John  Day 
or  the  Diceratherium  beds.  This  author  regarded  this  individual,  as  well  as  the  other  John 
Day  specimens,  as  identical  with  S.  nehrascensis,  from  the  White  River  deposits.  A  brief 
description  and  some  measurements  of  this  individual  were  furnisht  by  Cope  as  cited  above. 
The  specimen  now  bears  the  American  Museum's  catalog  number,  1357. 
In  form  this  species  is  of  moderate  width  and  height,  and  both  the  anterior  and  the  pos- 
terior borders  are  broadly  rounded.  The  upper  surface  is  convex  in  all  directions.  The 
peripherals  over  the  limbs  are  little,  if  any,  flared.  The  anterior  lobe  of  the  plastron  is  long  and 
projects  somewhat  beyond  the  carapace.    The  hinder  lobe  is  deeply  notcht. 

The  length  of  the  carapace  (plate  60;  text-fig.  498),  taken  in 
a  straight  line,  is  455  mm.;  its  greatest  width  is  360  mm.  The 
nuchal  resembles  that  of  S.  conspecta.  The  neurals  differ  from 
those  of  the  species  just  named  in  being  somewhat  broader  in 
proportion  to  their  length.  There  are  not  so  great  differences 
among  the  costals  as  regards  their  widths  as  in  iS".  conspecta;  but 
this  condition  may  be  due  to  individual  variation.  The  table 
herewith  gives  the  widths  of  each  of  the  costals  at  its  upper  and 
lower  ends,  excepting  the  first  and  the  eighth. 

The  peripherals  are  remarkable  for  their  thickness  and  the 
obtuseness  of  their  free  borders,  being  in  these  respects  quite 
unlike  those  of  S.  conspecta.  The  second  peripheral  is  35  mm. 
thick,  measured  on  the  sulcus  between  the  first  and  second  dermal  scutes.  The  border  is  obtuse, 
with  only  a  suggestion  of  an  edge.  In  the  type  of  S.  conspecta,  with  shell  nearly  as  long 
(415  mm.),  the  second  peripheral  is  only  25  mm.  thick,  and  it  comes  down  to  an  acute  edge. 
The  hinder  peripherals  have  a  very  obtuse  border,  nearly  resembling  the  border  of  the  fleshy 
part  of  one's  hand.  The  thickness  of  most  of  these  hinder  peripherals  is  35  mm.  The  cor- 
responding ones  of  S.  conspecta  are  25  mm.  thick  and  are  sharp-edged. 

The  total  length  of  the  plastron  (plate  61;  text-fig.  499)  reaches  415  mm.     The  anterior 
lobe  is  147  mm.  long  and  215  mm.  wide  at  the  base.    The  lip  extends  beyond  the  border  of  the 


Width 

Width 

Costal. 

upper  end. 

lower  end. 

60 

1 

33 

68 

55 

30 

36 

70 

44 

38 

35 

S3 

7 

20 

4i 

8 

ao 

54 

TESTUDINID^. 


393 


carapace  about  25  mm.  Its  anterior  extremity  is  broad  and  rounded.  The  distance  between 
the  points  where  the  gular  sulci  cross  the  free  border  is  1 17  mm.  The  greatest  thickness  of  the 
lobe,  at  the  base  of  the  lip,  is  30  mm.  There  is  a  slight  excavation  at  the  base  of  the  lip  on  the 
upper  surface.     The  edges  of  the  anterior  lobe  are  subacute. 

The  posterior  lobe  has  a  length  of  120  mm.  and  a  width  of  215  mm.  at  the  base.  The 
thickness  of  the  border  of  the  hypoplastron  just  behind  the  inguinal  notch  is  37  mm.;  whereas 
in  S.  conspecta  it  is  only  23  mm.    The  notch  in  the  rear  of  this  lobe  has  a  depth  of  25  mm. 


Figs.  498  and  499. — Styhmys  capax.    Carapace  and  plastron  of  type.     Xi-    No.  1357  A.  M.  N.  H. 

498.  Carapace.  499.  Plastron. 

The  form  and  proportions  of  the  scutes,  upper  and  lower,  do  not  differ  in  any  important 
way  from  those  of  S.  conspecta.  The  humero-pectoral  sulcus  falls  at  a  considerable  distance 
behind  the  border  of  the  entoplastron,  but  this  may  be  only  an  individual  peculiarity. 

This  species  is  remarkable  for  the  thickness  of  the  peripheral  and  plastral  bones  and  for 
the  obtuseness  of  the  free  borders  of  the  anterior  and  posterior  peripherals.  The  width  also  is 
proportionately  greater  than  that  of  S.  conspecta,  being  only  a  little  less  than  80  per  cent,  of  the 
length  of  the  carapace. 

Stylemys  conspecta  sp.  nov. 

Plate  64,  figs.  I,  2;   teit-figs.  500,  501. 
Stylemys  nebrasccnsis,  in  part,  Cope,  Vert.  Tert.  Form.  West.,  1884,  p.  769. 

The  type  of  this  species  is  a  large  and  fine  shell  which  belongs  to  the  Cope  collection  and 
is  now  in  the  American  Museum,  bearing  the  number  1358.  It  was  collected  in  1878,  by  Mr. 
Charles  H.  Sternberg,  and  appears  to  have  been  found  near  the  junction  of  North  Fork  and 
South  Fork  of  the  John  Day  River,  in  Grant  County,  Oregon.  Its  level  is  supposed  to  be  the 
middle  beds  of  the  John  Day  formation,  the  Diceratherium  beds  of  Marsh. 


394 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


CostaL 

Upper  end. 

Lower  end. 

2 

3° 

68 

3 

48 

zo 

j          4 

35 

70 

S 

38 

22 

6 

30 

68 

7 

ZI 

30 

Cope  regarded  these  turtles  as  belonging  to  Stylcmys  nehrascensis,  the  common  species  of 
the  White  River  beds  of  South  Dakota.  A  study  of  these  shells  and  a  careful  comparison  of 
them  with  the  South  Dakota  form  has  convinced  the  writer  that  they  are  specifically  different 
and,  moreover,  belong  to  two  distinct  species,  one  of  which  is  the  present,  the  other  S.  capnx. 

The  only  injury  that  the  type  specimen  suffered  during  fossilization  is  a  slight  lateral 
compression  and  a  moderate  thrusting  of  the  plastron  upward  toward  the  carapace.  The  total 
length  of  the  carapace  (plate  64,  fig.  i;  text-fig.  500)  in  a  straight  line  is  415  mm.;  the  width 
of  the  shell  is  215  mm.;  the  present  height  is  170  mm.  The  original  width  may  have  been  as 
much  as  300  mm.;  the  height  as  much  as  180  mm.  These  estimates  would  make  the  width  of 
the  shell  about  72  per  cent,  of  the  length.  The  carapace  is  high  and  convex  both  longitudinally 
and  transversely.  Over  the  bridges  the  sides  were  perpendicular  or  nearly  so.  There  was 
little  or  no  flare  to  the  anterior  and  posterior  peripherals.  In  outline,  both  the  front  and 
hinder  ends  are  broadly  rounded.  Where  the  sulci  crost  the  free  border  the  latter  is  mucronated. 
The  nuchal  bone  is  65  mm.  wide  along  the  free  border,  posteriorly  expanding  to  95  mm. 
The  first  neural  is  elongated  and  oval.  The  second  is  octagonal;  the  third  is  nearly  square; 
the  others,  hexagonal  and  mostly  with  the  shorter  sides  in  front.  The  anterior  pygal  is  bifur- 
cated. The  one  behind  it  is  four-sided,  its  hinder  border  fitting  in  a  notch  in  the  pygal.  The 
latter  bone  is  somewhat  incurved,  and  is  51  mm.  wide  and  50  mm.  long  on  the  midline. 

The  costal  plates  are  alternately  wide  and  narrow,  having 
nearly  as  high  a  degree  of  differentiation  as  those  of  the  genus 
Testudo.  The  accompanying  table  presents  the  widths  of  the 
upper  and  the  lower  ends. 

3  48       i       io  T\\t  first  and  second  peripherals  have  a  width  of  60  mm. 

along  the  free  border;  their  extent  backward  from  this  border 
is  57  mm.  The  eighth  is  70  mm.  high  and  47  mm.  wide.  All 
the  free  peripherals,  as  well  as  the  nuchal  and  the  pygal,  come 
down  to  an  acute  free  edge.  An  obscure  carina  crosses  the 
bridge  peripherals  from  the  free  border  of  the  anterior  to  the  free  border  of  the  posterior 
peripheral. 

The  nuchal  scute  is  27  mm.  long  and  16  mm.  wide.  The  first  vertebral  is  126  mm.  wide 
in  front.  The  second  and  third  are  about  83  mm.  wide;  the  fourth,  72  mm.;  the  fifth,  no  mm. 
wide  posteriorly.  On  the  anterior  peripherals  the  sulci  between  the  marginal  scutes  and  the 
costals  fall  considerably  below  the  sutures  between  the  peripheral  and  costal  bones.  On  the 
sides  and  posteriorly  the  sulci  are  little  below  the  sutures;  on  the  posterior  suprapygal,  above 
the  suture. 

The  plastron  (plate  64,  fig.  2;  text-fig.  501)  has  a  total  length  of  360  mm.  Its  general 
form  is  as  in  5.  nebrascensis.  The  anterior  lobe  has  a  length  of  120  mm.  and  a  width  of  166 
mm.  at  the  base.  It  did  not  project  beyond  the  front  of  the  carapace.  The  front  of  the  lip 
falls  within  the  general  curve  of  the  lobe.  The  lower  surface  of  the  lip  is  flat,  while  the  upper 
surface  curves  down  to  meet  it.  In  5.  nebrascensis  the  upper  and  the  lower  surfaces  are  about 
equally  convex.  The  entoplastron  has  the  form  that  it  has  in  S.  nebrascensis.  The  bridge 
has  a  width  of  150  mm. 

The  posterior  lobe  is  105  mm.  long  and  180  mm.  wide  at  the  base.  The  notch  in  the 
posterior  border  is  somewhat  larger  than  is  usual  in  iV.  nebrascensis.  As  to  the  thickness  of  the 
bone,  the  sloping  lateral  face  behind  the  inguinal  notch,  the  free  border  more  posteriorly,  and 
the  form  and  proportions  of  the  various  scutes,  the  lobe  presents  nothing  to  distinguish  it 
especially  from  the  White  River  species. 

Another  specimen  belonging  to  the  Cope  collection,  No.  1359,  presents  some  differences 
from  the  shell  just  described.  The  length  is  255  mm.,  the  width,  177  mm.  The  front  border 
is  slightly  concave  in  outline.  The  neurals  are  nearly  as  wide  as  those  of  the  larger  specimen 
just  described.  The  first  suprapygal  is  pentagonal,  not  bifurcated.  The  second  is  23  mm. 
high  and  56  mm.  wide,  and  appears  to  include  within  itself  the  limbs  of  the  usually  bifurcate 
first  suprapygal.  There  is  a  rather  sharp  carina  along  the  sides  above  the  bridge.  The 
anterior  vertebral  scute  is  hardly  as  wide  as  are  the  second  and  the  third;  while  the  fifth  is  but 
little  wider  than  those  just  mentioned. 


TESTUniNID^. 


395 


No.  1354  of"  the  Cope  collection  has  a  length  of  219  mm.  and  a  width  of  160  mm.  Its 
anterior  border  is  concave,  the  neurals  are  of  moderate  width,  the  pygal  is  bifurcate,  the 
peripherals  over  the  hind  limbs  somewhat  flaring,  and  there  is  a  conspicuous  and  sharp  carina 
along  each  side.  The  vertebral  scutes  are  like  those  of  No.  1359.  There  is  a  considerable 
depression  on  the  area  of  the  second,  third,  and  fourth  vertebral  scutes.  No.  1355  is  an  injured 
shell,  but  shows  an  anterior  slightly  concave  outline.  A  peculiarity  is  presented  in  the  anterior 
neurals.  The  first  is  broad  in  front  and  comes  into  contact  with  the  second  costal  plates. 
The  second  is  hexagonal,  with  the  shorter  sides  behind.  The  third  seems  to  have  had  four 
convex  sides.    The  anterior  vertebral  scute  has  been  64  mm.  wide;   the  second,  52  mm.  wide. 

No.  1351  is  a  small  turtle,  145  mm.  long,  which  has  the  first  and  fifth  vertebral  scutes 
about  as  wide  as  the  second  and  third. 


500. 


Figs.  500  and   501. — Stylemys  conspecta.     Carapace   and   plastron   of  type. 
Xi.  No.  1358  A.M.N.  H. 


500. 


apace. 


501.   Plastron. 


Notwithstanding  the  difl^erences  observed  among  the  specimens  just  described,  the  writer 
feels  compelled  to  refer  them  all  to  a  single  species. 

Stylemys  conspecta  appears  to  differ  from  S.  nehrascensis  in  the  following  respects:  The 
shell  is  narrower  in  proportion  to  its  length.  The  width  forms  about  75  per  cent,  of  the  length, 
whereas  in  S.  nehrascensis,  the  width  is  usually,  if  not  always,  about  85  per  cent,  of  the  length. 
In  S.  nehrascensis  the  second  and  third  neurals  are  almost  always  hexagonal.  Only  in  the 
specimen  described  by  Leidy  as  5.  culhertsonii  has  the  writer  observed  an  octagonal  second 
neural.  In  only  one  specimen  of  5.  conspecta.  No.  1354,  above  described,  has  the  second  been 
observed  to  be  not  octagonal,  and  this  specimen  has  other  irregularities.  The  costal  plates  of 
S.  conspecta  are  more  highly  differentiated  than  those  of  S.  nehrascensis,  as  has  been  described. 
The  anterior  peripherals  of  S.  conspecta  do  not  extend  so  far  backward  from  the  free  border 
as  those  of  S.  nehrascensis.    The  position  of  the  sulci  between  the  anterior  marginal  and  the 


396 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


costal  scutes  of  S.  conspecta  lies  well  in  front  of  the  hinder  border  of  the  peripheral  hones.  The 
carinae  along  the  sides  of  the  Oregon  species  are  usually  more  distinct  than  in  the  White  River 
form,  in  which  they  seem  never  to  be  well  developt. 

Siylemys  conspecta  belongs  to  a  later  epoch  than  does  S.  nehrascensis  and  has  evidently 
advanct  to  a  stage  nearer  to  Testudo  than  the  earlier  species. 

From  S.  capax  the  present  species  differs  in  being  of  a  more  elongated  form  and  in  having 
the  free  borders  of  the  peripherals  very  acute  instead  of  obtuse. 

Stylemys  calaverensis   Sinclair. 
Teit-figs.  502,  503. 
Stylemys  calaverensis,  Sinclair,  Univ.  of  Cai.  Pubs.;   Bull.  Dep't.  of  Geol.,  Ill,  1903,  p.  243,  figs.  I,  2. 

This  species  is  represented  by  little  else  than  the  type,  which  belongs  to  the  University  of 
California.  It  was  found  in  the  auriferous  gravels  about  2  miles  below  Vallecito,  Calaveras 
County,  California.  These  gravels  have  been  supposed  to  belong  in  the  Miocene.  It  has  not 
been  seen  by  the  writer,  and  the  following  description  is  based  wholly  on  Sinclair's  description 
and  illustrations. 

The  specimen  consists  of  the  crusht  anterior  two-thirds  of  the  carapace  and  plastron. 
The  carapace  (text-fig.  502)  includes  the  greater  portion  of  the  first  6  costals  ot  the  left  side, 
the  proximal  ends  of  the  second,  third,  fourth,  and  fifth  costals  of  the  right  side,  the  second 


502.  503. 

Figs.  502  and  503. — Stylemys  calaverensis.     Carapace  and  plastron  of  type.     X  J- 

502.  Carapace,     c.^.  l,c./).  2,  first  and  second  costal  bones;  «.l,n.2, 

neurals;   m.  s.  3,  m.  s.  4,  third  and  fourth  marginal  scutes. 

503.  Portion  of  plastron. 

and  third  neurals,  and  a  portion  of  the  first.  The  plastron  is  represented  from  the  front  to 
near  the  hinder  border  of  the  hypoplastron. 

In  the  crushing  that  has  affected  the  shell  there  has  occurred  a  slipping  of  parts  near  the 
midline.  The  first  costal  of  the  left  side  overlaps  a  portion  of  the  first  neural.  The  second  and 
third  neurals  retain  their  original  relations  with  the  second  and  third  costals  of  the  right  side, 
but  overlap  the  proximal  ends  of  those  of  the  left  side.  The  three  next  costals  of  the  left  side 
overlap  and  hide  the  corresponding  neurals.  Hence,  only  the  second  and  third  neurals  and 
a  portion  of  the  first  are  to  be  seen. 

[jlH  An  estimate  based  on  Sinclair's  description  and  illustrations  and  the  assumption  that  the 
proportions  of  the  species  are  about  as  they  are  in  Stylemys  nehrascensis  shows  that  the  carapace 
had  a  length  of  about  405  mm.  and  a  width  of  about  400  mm.,  being  thus  nearly  as  broad  as 
long.  The  bridge  peripherals  of  the  left  side  show  distinctly  in  Sinclair's  figure,  here  repro- 
duced, but  this  is  probably  due  to  the  crushing  of  the  specimen  toward  the  right  side.  On  the 
other  hand  the  peripherals  in  front  of  these  show  hardly  as  much  of  their  width  as  might  be 


TESTUDINID^. 


397 


1 

Distal 

Costal. 

end. 

end. 

2 

5»± 

4Z± 

3 

68 

4i 

4 

SS 

67 

5 

i* 

37 

6 

38±     ' 

S'± 

expected.  No  part  of  the  nuchal  appears.  The  first  neural  was  wider  than  the  second,  and  in 
contact  with  the  second  costal.  Its  greatest  width  was  near  64  mm.,  while  the  second  has 
measured  55  mm.  in  width.  As  in  some  specimens  of  S.  nehrascensis  and  in  probably  all 
individuals  of  the  John  Day  species  of  the  genus,  the  third  neural  was  tetragonal.  Correspond- 
ing to  this  condition,  the  third  costal  was  in  contact  with  the  second,  third,  and  fourth  neurals. 

The  costals  are  only  slightly  modified  as  respects  the  widths 
of  the  opposite  ends  of  each.  The  measurements  shown  in  the 
table  taken  from  Sinclair's  description  and  illustration  show  the 
extent  of  the  modification. 

The  carapacial  scutes  resembled  closely  those  of  S.  nehra- 
scensis. An  estimate  makes  the  first  vertebral  scute  to  have 
been  about  184  mm.  wide  in  front.  The  second  vertebral  was 
about  108  mm.  wide. 

The  plastron  (text-fig.  503)  was,  according  to  Sinclair, broken 
away  at  the  extremity  of  the  epiplastral  lip.  It  must  therefore  have  been  rounded.  The 
anterior  lobe  had  a  length  of  about  100  mm.,  the  base  a  width  of  200  mm.,  resembling  thus 
the  anterior  lobe  of  S.  nehrascensis.  The  entoplastron  is  rhomboidal  in  form,  thus  resem- 
bling that  of  some  species  of  Testudo.  Its  length  is  81  mm.,  its  width  is  88  mm.  The 
portion  of  the  plastron  present  evidently  extended  backward  to  near  the  hinder  border  of 
the  hypoplastron;  but  did  not  reach  the  inguinal  notches.  The  bridge  must  therefore  have 
had  a  width  of  at  least  172  mm. 

The  sulci  separating  the  scutes  of  the  plastron  are  stated  to  be  very  obscure.  The  gulars 
and  humerals  resemble  those  of  S.  nehrascensis. 

It  appears  to  be  quite  certain  that  this  species  belongs  to  the  genus  Stylemys.  It  appears 
to  differ  from  all  the  others  in  having  a  very  broad  first  neural,  which  comes  into  contact  with 
the  second  costal  bone,  and  in  having  the  entoplastron  more  pointed  behind.  From  the  known 
John  Day  species  it  differs  in  having  the  costal  bones  less  wedge-shaped. 

Genus  TESTUDO  Linnaeus. 

Carapace  extensively  joined  to  plastron  by  suture.  Inguinal  buttresses  rising  little,  if  any, 
above  the  costo-peripheral  sutures.  Second  and  fourth  neurals  usually  octagonal;  the  third 
and  fifth  usually  quadrangular.  Epiplastral  lip  usually  projecting  abruptly  from  the  general 
contour  of  the  anterior  lobe.  Plastron  notcht  behind.  Crushing-surfaces  of  jaws  with  longi- 
tudinal ridges  and  grooves.  No  median  longitudinal  ridge  in  front  of  the  choanae.  Digits 
much  shortened  and  foot  club-shaped. 

Type:     Testudo  grceca  Linnaeus. 

From  both  Hadrianus  and  Stylemys  this  genus  is  distinguisht  by  the  much  higher  grade  of 
differentiation  which  has  been  attained  by  the  elements  of  the  shell.  From  Stylemys  it  is 
further  distinguisht,  as  it  is  also  from  Gopherus,  in  having  no  longitudinal  ridge  in  the  midline 
of  the  upper  jaw  in  front  of  the  choanae.  Some  living  species  have  the  neurals  and  costals 
little  more  differentiated  than  in  Stylemys,  and  in  T.  inusitata,  described  below,  none  of  the 
neurals  is  octagonal  or  quadrangular. 

Analysis  of  the  Known  North  American  Fossil  Species  of  Testudo. 

/f'.  Oligocene  species: 

a.  Titanotherium  beds. 

1.  Peripheral  sulci  deeply  imprest;   epiplastral  lip  more  than  twice  as  wide  as  long  .  .    brotitops 

2.  Costals  very  thick;    deeply  imprest  by  lines  of  growth  of  the  horny  scutes exnmatn 

aa.  Oreodon  beds. 

3.  Lip  nearly  as  wide  as  long;   its  sides  parallel thomsotn 

4.  Shell  flattened;    no  octagonal  neural;   epiplastral  lip  abruptly  projecting,  tootht 

in  front laticunea 

5.  Lip  truncated,  three  times  as  wide  as  long hgotiia 

6.  Lip  truncated,  short;  pectoral  scutes  about  one-fourth  as  wide  as  abdominals.  .     amphithomx 

7.  Lip  square;  the  gulars  not  reaching  the  entoplastron quaJrata 

8.  Lip  narrow  and  wedge-shaped cultrata 


398  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

A^.   Lower  Miocene  species: 

9.  Lip  prominent,  twice  as  wide  as  long,  and  nearly  as  thick  as  long peragrans 

10.  Pygal  convex  up  and  down  on  upper  side aremvaga 

11.  Lip   not   greatly  projecting;    pectoral  scutes    nearly  half  as  wide  on   midline  as 

abdominals vaga 

12.  No  4-sided  or  8-sided  neurals;  pectoral  scutes  about  one-fifth  as  wide  as  abdom- 

inals         emilia 

A^.   Deep  River  and  Pawnee  Creek  (Middle  Miocene)  species: 

i^.  Lip  not  projecting  far;   pectorals  only  one-seventh  the  width  of  the  abdominals.  .  .  jam 

14.  Neurals  as  in  T.  emiliie;  the  gulars  reaching  the  entoplastron inusitata 

15.  Shell  broad  and  deprest;  lip  tapering;  pectorals  about  one-third  the  abdominals.  .        pansa 

16.  Shell  vaulted;  pectorals  one-twenty-fifth  the  abdominals,  or  less osborniana 

A*.   Loup  Fork: 

17.  Lip  abruptly  projecting;  pectorals  one-eighteenth  the  width  of  the  abdominals  ...  .    impensa 

18.  Hinder  peripherals  and  pygal  with  free  border  flared  upward;    pygal  narrowing 

toward  the  free  border undata 

19.  Pygal  plane;  its  sides  parallel klettiana 

20.  Lip  rounded,  little  projecting;   resembles  vaga  of  the  Lower  Miocene ntobrarensis 

21.  Strongly  projecting  lip;  pectorals  about  one-eleventh  the  width  of  abdominals.  .      orthopygia 

22.  Skull  only;    consult  figures gilberti 

23.  First  and  third  neurals  4-sided;    second   and   fourth   octagonal;    lip   prominent; 

pectorals  about  one-fifth  the  width  of  abdominals edte 

24.  First,  third,  and  fifth  neurals  4-sided;  second  and  fourth  octagonal;  lip  moderately 

prominent;   pectorals  one-fourth  the  width  of  abdominals hollandt 

A^.   Pliocene  species: 

25.  Lip  prominent;  all  the  sulci  deeply  sunken  and  wide;  free  borders  of  the  peripherals 

deeply  nocht  by  the  sulci turgida 

26.  Shell  broad  and  deprest;   the  vertebral  scutes  wider  than  long;   shell  thin perienuis 

27.  Lip  prominent;  truncated;  pectoral  scutes  nearly  half  as  wide  as  the  abdominals  . .  campester 

28.  Hinder  peripherals  thick  and  with  very  obtuse  free  border obtusa 

29.  Anterior  lobe  of  plastron  rapidly  tapering  forward;    borders  of  lip  continued  in 

same  lines;  bones  thick  and  heavv crassiscutata 

A".   Pleistocene  species: 

30.  Lip  about  four-fifths  as  long  as  wide,  thick  behind;   notch  in  rear  of  plastron  four 

times  as  wide  as  deep laticaudata 

31.  Lip  rounded;   notch  in  rear  not  three  times  as  wide  as  deep;  borders  of  hinder 

lobe  rapidly  converging  backward hexagonata 

32.  Lip  rounded  but  prominent;    borders  of  hinder  lobe  slowly  converging atascosts 

Testudo  brontops  Marsh. 
Plate  65,  figs.  I,  2;    text-figs.  504,  505. 

Testudo  brontops.  Marsh,  Amer.  Jour.  Sci.  (3),  XL,  1890,  p.  179,  plate  viii;  Vert.  Foss.  Denver  Basin, 
in  Mon.  U.  S.  Geol.  Surv.,  xxvii,  1897,  pp.  523,  527,  figs.  95,  96. — Dana,  Manual  Geol.,  1896, 
p.  901,  fig.  1516. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  451;  Amer.  Jour.  Sci.,  (4) 
xviii,   1904,  p.   272,  figs.  6,   7. 

The  type  of  this  species  is  a  fine  large  shell  which  was  collected  for  Prof.  O.  C.  Marsh,  in 
the  year  1888,  by  Mr.  J.  B.  Hatcher,  and  is  now  in  the  Peabody  Museum,  at  Yale  University. 
It  was  obtained  in  the  Titanotherium  beds  of  Indian  Creek,  in  the  southeastern  corner  of 
Pennington  County,  South  Dakota.  No  considerable  parts  of  the  shell  are  missing  and  it  has 
been  only  slightly  crusht.    The  specimen  bears  the  record  "  Box  27,  1985." 

In  form  this  magnificent  tortoise  was  broad  and  probably  of  only  moderate  height.  The 
front  of  the  carapace  (plate  65,  fig.  i ;  text-fig.  504)  is  somewhat  concave  in  outline,  the  lateral 
angles  broad,  rounded  and  flaring  upward.  The  sides  were  nearly  perpendicular.  The  hinder 
border  is  broadly  rounded,  with  the  peripherals  over  the  limbs  considerably  flaring  and  with 
the  pygal  incurved  toward  its  free  border.  Where  the  sulci  cross  the  free  borders  of  the  periph- 
erals the  latter  are  somewhat  notcht;  and  where  they  cross  the  borders  of  the  carapace  above 
the  bridges  they  lie  in  grooves  so  deep  that  the  interspaces  appear  to  be  strongly  swollen.  The 
free  borders  of  all  the  peripherals  come  down  to  an  acute  edge.  The  length  of  the  carapace 
is  71 1  mm.;   the  greatest  width  is  651  mm. 


TESTUDINID^. 


399 


The  nuchal  has  probably  a  width  of  about  125  mm.  along  the  front  border,  but  here  the 
sutures  are  indeterminable.  The  greatest  width  is  175  mm.  and  the  length  along  the  midline 
150  mm.    The  first  neural  is  oval;   the  second  and  the  fourth  octagonal;  the  third,  hexagonal. 

The  fifth  was  probably  hexagonal,  but 
a  considerable  portion  of  it  appears  to 
have  been  crusht  down  beneath  the 
fourth.  The  sixth,  seventh,  and  eighth 
are  approximately  hexagonal.  The 
table  gives  the  dimensions  of  the 
neurals. 

The  anterior  suprapygal  is  bifur- 
cate, having  a  total  height  of  about  87 
mm.,  and  inclosing  between  its  right 
and  left  limbs  the  second  suprapygal. 
The  latter  has  a  height  of  84  mm.  on 
the  midline  and  a  breadth  of  125  mm. 
The  costals  are  alternately  wider  and  narrower  at  their  upper  ends  and  vice  versa  at  their 
lower,  but  the  amount  of  the  differentiation  is  not  great.  Omitting  the  first  the  dimensions 
are  given  in  the  table  above. 


1             Dimensions  of  ne 

Urals. 

Dimensions  of  cosMl  bones. 

No. 

Length. 

Width. 

Width  of 

No.                        , 

I  upper  end. 

Width  of 
lower  end. 

I                  127 

75 

1 

56 

106 

2 

79 

ICO 

3                 100 

73 

3 

95 

97 

4          i         5* 

90 

4 

73 

100 

5                  94 

56 

5 

63 

6                  61 

95 

6          ;         62 

87 

7                     40 

75 

7 

50 

78 

8          1         43 

62 

8 

37 

7^ 

504.  505. 

Figs.  504  and  505. — Testudo  brontops.     Carapace  and  plastron  of  type.     Xl. 
504.  Carapace.  505.  Plastron. 

The  upper  ends  of  the  third  costals  have  been  somewhat  injured  by  crushing.  The 
proximal  ends  of  the  fifth  costals  also  have  been  damaged  so  that  their  exact  width  is  uncertain. 
On  the  right  side  the  greater  portion  of  the  fifth  costal  has  been  pushed  down  out  of  sight. 

The  second  peripheral  occupies  about  150  mm.  of  the  free  border,  and  extends  backward 
1 10  mm.     It  is  nearly  flat  above,  concave  beneath,  and  attains  a  thickness  of  ^J  mm.     The 


400  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

bridge  peripherals  extend  upward  about  140  mm.  above  the  slight  carina  which  joins  the  border 
of  the  third  peripheral  with  that  of  the  seventh.  From  the  seventh  peripheral  the  height  of 
these  bones  diminishes  to  the  pygal.  The  latter  has  a  height  of  82  mm.;  a  width  of  125  mm.  at 
the  upper  border,  and  of  100  mm.  at  the  free  border. 

The  nuchal  scute  is  56  mm.  long  and  only  7  mm.  wide.  The  first  vertebral  has  a  width  of 
230  mm.  in  front  and  a  length  of  165  mm.  The  transverse  extent  of  the  vertebral  scutes  is  con- 
siderably less  than  that  of  the  costals.  The  width  of  the  second  is  1 90  mm. ;  that  of  the  third 
probably  about  the  same,  but  its  lateral  boundaries  are  mostly  hidden;  that  of  the  fourth  is 
150  mm.;  that  of  the  fifth,  at  the  posterior  end,  is  180  mm.  The  second  costal  scute  has  a  trans- 
verse extent  of  230  mm. 

The  sulci  between  the  anterior  marginal  scutes  lie  in  grooves;  and,  as  they  approach  the 
free  border,  they  curve  toward  the  midline.  Those  of  the  bridge  region  are  directed  foi"ward  at 
their  lower  ends.  The  lower  ends  of  these  sulci  and  the  longitudinal  ones  between  the  marginal 
and  the  plastral  scutes  also  lie  in  deep  valleys.  The  supracaudal  scute  is  175  mm.  wide  at 
its  lower  end.    Its  upper  end  overlaps  the  posterior  suprapygal  bone. 

The  plastron  (plate  65,  fig.  2;  text-fig.  505)  is  quite  concave,  a  condition  which  indicates 
that  the  animal  was  a  male.  The  length  of  the  anterior  lobe  is  222  mm.;  its  width  is  380  mm. 
The  anterior  lip  extends  beyond  the  border  of  the  carapace  about  60  mm.  It  projects  boldly 
from  the  general  contour  of  the  anterior  lobe  and  its  lateral  borders  converge  somewhat  as  they 
approach  the  bilobed  anterior  border.  The  length  of  the  lip  beyond  the  points  where  the  gulo- 
humeral  sulci  cross  the  free  borders  of  the  epiplastra  is  56  mm.;  the  width  at  the  base  is  135  mm. 
A  broad  and  deep  groove  occupies  the  median  line  of  the  lip  and  ends  in  the  notch  in  the  front 
of  the  lip.  The  greatest  thickness  of  the  lip  is  50  mm.  The  superior  surface  is  somewhat 
convex  from  side  to  side.  In  all  probability  there  is  an  excavation  in  the  hinder  portion  of  the 
lip  above,  but  the  matrix  has  not  been  removed. 

The  entoplastron  has  a  width  of  175  mm.  and  a  length  of  120  mm.  The  bridge  is  300  mm. 
wide.  The  hinder  lobe  has  a  length  of  about  175  mm.  and  a  width,  at  the  base,  of  370  mm.,  or 
slightly  less.  The  notch  in  the  rear  is  about  40  mm.  deep  and  about  100  mm.  wide.  The  xiphi- 
plastra  are  each  165  mm.  long.  Just  behind  the  inguinal  notch  the  border  of  the  posterior  lobe 
is  50  mm.  thick  and  forms  a  nearly  perpendicular  face.  Further  backward  the  steepness  of 
the  slope  and  its  height  are  rapidly  reduced. 

The  sulci  bounding  the  dermal  scutes  are  deeply  imprest.  Those  bounding  the  gular 
scutes  lie  at  the  bottom  of  deep  valleys,  which  proceed  forward  from  the  entoplastron,  one  to 
each  side  of  the  base  of  the  lip  and  one  to  the  front  on  the  midline.  The  gulars  encroach  some- 
what on  the  front  of  the  entoplastron.  The  humero-pectoral  sulcus  starts  on  each  side  at  the 
axillary  notch,  runs  inward  and  backward,  then  inward  and  forward.  Near  the  midline  it  is 
somewhat  irregular,  bending  in  its  course  slightly  backward.  On  the  left  side  it  traverses 
the  border  of  the  entoplastron.  The  width  of  the  pectoral  along  the  midline  is  between 
50  mm.  and  60  mm.  The  abdominals  occupy  240  mm.  of  the  midline;  the  femorals,  100  mm; 
and  the  anals,  about  60  mm. 

A  large  specimen  of  Testudo  was  collected  in  the  Titanotherium  beds  of  South  Dakota  by 
the  party  from  the  American  Museum  in  1904.    It  appears  to  belong  to  this  species. 

This  species  is  especially  interesting  because  of  its  being  the  oldest  known  North  American 
species  of  the  genus.  T.  ammon,  described  from  the  Upper  Eocene  of  Egypt,  appears  to  be 
still  older. 

Testudo  thomsoni  sp.  nov. 
Plate  66,  figs.  1-5. 

The  only  remains  of  this  species  at  present  known  were  obtained  in  1904,  by  Mr.  Albert 
Thompson,  of  the  American  Museum  of  Natural  History,  at  Corral  Draw,  in  Ziebach  County, 
South  Dakota.  They  were  found  in  a  block  of  limestone  which  had  come  from  the  Lower 
Oreodon  beds.  The  parts  secured  are  the  skull,  the  greater  portion  of  the  anterior  lobe  of  the 
plastron,  some  cervical  vertebrae,  and  parts  of  the  left  foreleg.  These  bear  the  catalog  number 
3940.  Other  portions  of  the  skeleton  were  in  the  block;  but  they  were  not  secured,  because 
they  were  supposed  to  belong  to  the  very  common  species,  Stylemys  nebrascensis. 


TESTUDINID^.  4OI 

That  which  distinguishes  this  species  from  those  of  the  genus  Stylemys  is  the  prominent 
epiplastral  lip  (plate  66,  fig.  1).  How  long  this  was  originally  it  is  now  impossible  to  say, 
for  the  anterior  end  has  been  broken  away.  The  portion  remaining  extends  32  mm.  beyond  a 
line  joining  the  anterior  ends  of  the  gulo-humeral  sulci.  The  thickness  of  the  broken  end  is 
26  mm.  It  appears  probable  therefore  that  the  lip  was  at  least  60  mm.  long.  Its  width  at  the 
base  is  80  mm.  The  lower  and  upper  faces  are  convex  from  side  to  side.  The  free  edges  are 
acute,  as  are  also  the  epiplastral  edges  behind  the  lip.  Opposite  the  anterior  ends  of  the  gulo- 
humeral  sulci  the  thickness  of  the  lip  is  32  mm.  Seen  from  below,  the  plastron  rises  toward  the 
lip,  so  that  the  latter  projects  on  a  slightly  higher  plane.  Seen  from  the  upper  side,  the  lip  is 
carried  backward  20  mm.  behind  the  line  joining  the  anterior  ends  of  the  gulo-humeral  sulci. 
It  attains  a  thickness  of  35  mm.,  then  slopes  off  rapidly  to  the  entoplastron. 

The  entoplastron  has  a  length  of  93  mm.  along  the  midline  and  a  width  of  107  mm.  Its 
form  is  approximately  rhomboidal. 

The  gular  scutes  extend  on  the  entoplastral  bone.  The  sulci  are  deeply  imprest.  Altho 
the  plastron  is  present  at  the  midline  a  distance  of  40  mm.  behind  the  hinder  border  of  the  ento- 
plastron, there  is  no  certain  trace  of  the  humero-pectoral  sulcus. 

The  skull  is  in  a  good  state  of  preservation.  The  premaxillae  are  missing,  as  are  most  of 
the  right  maxilla,  the  tip  of  the  left  dentary,  and  the  anterior  half  of  the  right  dentary. 

The  length  of  the  skull  (plate  66,  figs.  2-4)  from  the  upper  border  of  the  nasal  opening  to 
the  occipital  condyle  is  85  mm.  The  breadth  just  in  front  of  the  tympanic  cavities  is  62  mm.; 
between  the  outer  borders  of  the  articulation  of  the  lower  jaw,  60  mm.  In  front  of  the  temporal 
fossae  the  upper  surface  of  the  skull  is  quite  flat.  Seen  from  the  side  the  upper  surface  of  the 
skull  is  nearly  straight  from  the  snout  to  the  end  of  the  supraoccipital.  The  interorbital  space 
is  23  mm.  wide.  The  jugal  arch  has  a  height  of  13  mm.;  the  postorbital  arch  a  width  of  10  mm. 
The  frontals  furnisht  a  small  portion  of  the  rim  of  the  orbit.  The  antero-posterior  diameter 
of  the  orbit  is  24  mm.;  the  perpendicular  diameter,  18  mm.  The  roof  of  the  mouth  is  moder- 
ately vaulted,  and  is  traverst  along  the  midline  by  a  sharp  ridge.  The  triturating  surface  of  the 
upper  jaw  has  a  longitudinal  rough  ridge  and  a  less  conspicuous  inner  ridge.  Posteriorly  the 
palate  is  reduced  to  a  width  of  13  mm. 

The  dentary  bone  (plate  66,  fig.  5)  is  channeled  from  the  coronoid  process  to  near  the 
symphysis,  to  receive  the  dentated  ridge  of  the  upper  jaw.  The  lower  jaw  is  19  mm.  high  at  the 
coronoid  process. 

The  distal  half  of  the  left  humerus  is  present.  The  width  of  the  distal  end  is  54  mm.  The 
left  radius  has  an  extreme  length  of  92  mm.  A  claw  phalange  has  a  length  of  20  mm.  and  a 
width  of  16  mm. 

The  cervical  vertebrae  are  more  or  less  damaged.     One  has  the  centrum  40  mm.  long. 

This  was  a  large  turtle,  the  length  of  the  carapace  being  estimated  at  about  625  mm. 

Thru  the  kindness  of  Dr.  S.  W.  Williston,  of  the  University  of  Chicago,  the  writer  has 
been  permitted  to  examine  a  testudinid  skull  which  was  collected  in  1894  by  Dr.  George  Baur. 
It  was  obtained  in  the  same  locality  as  the  specimen  above  described  and  probably  in  the  same 
beds.  The  skull  is  somewhat  fragmentary  and  lacks  the  symphyses  of  the  upper  and  lower 
jaws.  It  appears  to  have  belonged  to  T.  thomsoni,  but  it  presents  some  differences.  The  orbit 
is  more  nearly  circular  than  in  the  type;  but  the  type  may  have  suffered  some  distortion  in  this 
region.  The  upper  longitudinal  outline  of  the  skull  of  Dr.  Baur's  specimen  is  not  so  straight, 
the  supraoccipital  crest  not  rising  so  high.  The  skull  is  that  of  a  smaller  specimen  and  the 
depression  of  the  crest  may  be  due  to  an  earlier  stage  of  growth,  to  sex,  or  to  individual 
variation. 

Testudo  exomata  Lambe. 

Plate  66,  figs.  6,  7;    text-figs.  506-508. 
Testudo  exomata,  Lambe,  The  Ottawa  Naturalist,  xix,  1906,  p.  187,  plate  iii,  figs.  1-3. 

All  the  known  specimens  of  the  present  species  belong  to  the  Geological  Survey  of  Canada. 
They  consist  wholly  of  fragments  of  costal  plates,  which  were  collected  in  1904,  by  Mr.  Law- 
rence M.  Lambe,  vertebrate  paleontologist  of  the  Canadian  Survey,  in  the  Oligocene  beds  of 

26 


402 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


Figs 


506.  507. 

506-508. — Tcstudo  exornata. 
of  type.     Xl. 

506.  Fragment  of  first  costal. 

507.  Proximal  end  of  sixth  costal. 

508.  Proximal  half  of  third  or  fifth  costal. 


the  Cypress  Hills,  Assiniboia.     These  costals  are  remarkable  for  their  thickness,  the  deeply 
imprest  sulci,  and  the  strongly  markt  lines  of  growth  of  the  horny  scutes. 

Figs.  6  and  7  of  plate  66  represent  the  distal  half  of  the  left  fifth  costal,  which  is  taken  by 
Mr.  Lambe  as  the  type  of  the  species.  Fig.  6  shows  the  outer  surface.  This  is  12  mm.  wide  at 
the  upper  end,  10  mm.  at  the  lower.  It  might  be  taken  for  the  bone  of  a  young  animal  were 
it  not  for  the  great  thickness.  The  anterior  sutural  border  has  a  thickness  of  a  little  more  than 
4  mm.  From  this  border  the  bone  thickens  rapidly,  so  that  the  posterior  border,  at  the  lower 
end  of  the  bone,  is  8  mm.  thick.  Seen  from  the  inner  surface  (fig.  7)  the  bone  presents,  on  the 
hinder  half  of  its  width,  a  prominent  half-ridge,  which  was  evidently  completed  on  the  succeed- 
ing costal.  The  larger  portion  of  the  ridge  has  been  on  the  sixth  costal,  and  has  been  developt 
to  receive  the  inguinal  buttress  of  the  plastron.  It  looks  indeed  as  if  this  buttress  had  ascended 
about  15  mm.  above  the  border  of  the  costals  and  had  been  articulated  with  both  the  fifth  and 
the  sixth,  but  principally  with  the  latter.   So  far  as  the  writer  is  aware,  in  other  species  of  TestuJo 

the  buttress  articulates  only  with  the  sixth 
costal.  At  the  lower  end  of  the  fifth  costal  is 
a  pit  for  a  process  of  the  seventh  peripheral. 
It  is  evident  that  this  costal  was  much  broader 
at  the  proximal  end  than  at  the  distal. 

There  is  present  a  portion  of  the  left  first 
costal  plate  (fig.  506).  In  this  figure  the 
upper  border  was  directed  toward  the  head, 
the  right  hand  border  toward  the  first  neural. 
At  the  upper  end  the  fore-and-aft  width  of 
the  bone  was  about  30  mm.  From  this  it  is 
estimated  that  the  length  of  the  carapace  was 
about  200  mm.  At  its  posterior  border  the 
bone  is  4.5  mm.  thick.  On  the  inner  sur- 
face is  a  ridge  which  past  upward  into  the 
head  of  the  rib.  The  outer  surface  of  the  bone  is  markt  by  the  lines  of  growth  of  the 
first  costal  scute.  Fig.  507  represents  the  outer  surface  of  the  proximal  end  of  another  costal, 
probably  the  sixth  costal  of  the  left  side.  Where  the  bone  joined  the  sixth  neural  it  is  8  mm. 
thick.  The  sulci  are  narrow,  but  deeply  imprest.  The  outer  surface  shows  the  lines  of 
growth  of  the  scutes.  At  its  upper  end  the  bone  is  15  mm.  wide  and  appears  to  have  expanded 
toward  the  distal  end. 

Fig.  508  represents  a  costal  of  a  young  individual,  evidently  the  third  or  the  fifth,  probably 
the  fifth  of  the  right  side.  The  width  at  the  upper  end  is  12  mm.  The  width  at  the  distal  end 
of  the  fragment,  probably  about  the  middle  of  the  length  of  the  costal,  has  increased  to  9  mm. 
Its  thickness  is  a  little  more  than  3  mm.  On  the  under  side  of  the  bone  is  found  the  base  of  a 
rather  well-developt  rib-head. 

Testudo  laticunea  Cope. 

Plate  67,  figs.  I,  2;   text-figs.  509-515. 

TestuJo  laticunea,  Cope,  Palaeont.  Bull.  No.  15,  187^,  p.  6;  Synop.  New  Vert.  Tert.  Colorado,  1873, 
p.  19;  Ann.  Rep.  Geol.  and  Geog.  Surv.  Terrs.,  1873  (1874),  p.  51 1 ;  Vert.  Tert.  Form.  West,  1884, 
pp.  762,  765,  plate  Ixi,  figs.  I,  la. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  451. 

In  his  original  description  Professor  Cope  states  that  he  had  in  his  possession  several  speci- 
mens of  this  species,  but  he  does  not  designate  any  as  the  type.  In  his  description  of  1884  one 
individual  in  a  good  state  of  preservation  was  used  as  the  basis  of  the  description  and  was 
figured.  This  must  now  be  regarded  as  the  type,  especially  since  the  other  specimens  occur- 
ring in  the  Cope  collection  are  very  fragmentary.  This  type  is  now  in  the  American  Museum 
of  Natural  History  and  bears  the  number  1 160.  All  of  Cope's  specimens  were  obtained  in  the 
Oligocene  beds  at  the  head  of  Horse  Tail  Creek,  in  northeastern  Colorado.  These  deposits 
belong  to  the  level  known  as  the  Oreodon  beds. 

The  specimen  is  slightly  distorted,  somewhat  fractured,  and  some  portions  are  missing. 
A  fracture  extends  along  the  midline  of  the  anterior  part  of  the  carapace  and  the  elements  of 


TESTUDINID^. 


403 


the  right  side  have  been  thrust  forward  about  10  mm.  in  front  of  those  on  the  left.  Some  por- 
tions of  neurals,  costals,  and  peripherals  are  missing,  especially  on  the  right  side,  but  all  parts 
are  represented  on  one  side  or  the  other.  The  outer  ends  of  the  hyoplastra  are  wanting  and 
part  of  the  outer  end  of  the  left  hypoplastron. 

The  species  was  a  broad  and  rather  deprest  one,  and  in  many  respects  it  resembled  the  recent 
Gopherus  polyphemus.  The  following  table  presents  some  of  the  dimensions.  When  Cope's 
measurements  differ  they  are  added  in  parentheses. 

Length  of  carapace ^^o  (408)  Width  of  anterior  lobe 200 

Width  of  carapace 356  Greatest  length  of  posterior  lobe   120 

Greatest  length  of  plastron 4+0  Width  of  base  of  posterior  lobe 210  (200) 

Length  of  anterior  lobe 132 

The  anterior  border  of  the  carapace  (plate  67,  fig.  i;    text-fig.  509)  is  truncate;  the  pos- 
terior border  between  truncate  and  rounded.   The  free  edge  is  everywhere  acute.  Where  the 


509. 


Figs.  509  and  510. — Testudo  lattcunea.     Carapace  and  plastron  of  type.     Xi- 
509.  Carapace.  510.  Plastron. 

sulci  between  the  marginal  scutes  cross  the  free  border  there  is  present  a  tooth  or  mucro.  The 
height  of  the  bridge  peripherals  was  about  85  mm.;  while  the  extent  of  the  corresponding 
costals,  transverse  to  the  animal,  was  about  145  mm.  The  greatest  thickness  of  the  first  periph- 
eral is  18  mm.  The  nuchal  bone  occupies  62  mm.  of  the  free  border,  and  its  greatest  width  is 
95  mm.  The  hinder  peripherals  have  a  slight  flare.  The  eighth  has  a  height  of  70  mm.  and  a 
thickness  of  22  mm.  The  pygal  has  a  length  of  34  mm.  along  the  midline,  a  transverse  extent 
of  57  mm.  at  the  upper  border,  and  of  45  mm.  along  the  free  border.  The  first  suprapygal  is 
bifurcate  and  comes  into  contact  with  the  eleventh  peripheral  of  each  side,  but  not  with  the 
pygal.    The  second  pygal  is  broader  than  long. 

The  neurals  have  not  attained  so  high  a  degree  of  difl^erentiation  of  form  as  they  have  in 
most  of  the  species  of  the  genus.    None  of  the  series  is  octagonal.    AH  are  hexagonal,  except 


404 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


NeuraL 

Length . 

Width. 

56 

46 

4* 

40 

33 

37 

35 

50 

39 

48 

3^ 

45 

7 

28 

46 

g 

2g 

^9 

the  third,  which  is  nearly  square,  and  the  fifth,  which  is  rhomboidal.    The  table  gives  the  great- 
est length  and  width  of  each  neural. 

The  costal  plates  have  undergone  considerable  differentiation  in  form.  The  second, 
fourth,  sixth,  and  eighth  have  narrow  proximal  ends  and  wide  distal  ends;   while  the  third 

and  fifth  have  wide  proximal  and  narrow  distal  ends.  The 
third  comes  into  contact  with  3  neurals,  the  fifth  with  only  2. 
It  is  not  unlikely,  however,  that  other  individuals  will  present 
variations  in  the  forms  of  the  neurals  and  costals. 

The  free  borders  of  the  plastron  (plate  67,  fig.  2;  text-fig.  510) 
are  acute.  The  dimensions  of  the  lobes  are  given  in  the  table  ot 
measurements.  The  anterior  lip  projects  beyond  the  front  ot  the 
carapace  about  50  mm.  The  base  is  87  mm.  wide  from  the 
crossings  of  the  gular  sulci  over  the  free  border.  The  length  of 
the  lip  is  43  mm.  The  sides  converge  somewhat,  and  the  rounded 
anterior  border  is  furnisht  with  6  blunt  teeth.  The  upper  surface 
of  the  lip  is  convex,  and  it  rises  backward  until  the  thickness  becomes  33  mm.  The  hinder 
face  of  this  thickening  is  somewhat  excavated.  The  entoplastron  is  pointed  in  front,  broad 
and  somewhat  rounded  behind. 

The  posterior  lobe  ends  behind  in  2  broadly  rounded  apices,  which  inclose  a  deep  and 
sharp  notch.  The  borders  of  the  apices  are  tootht.  Just  behind  the  inguinal  notch  the  border 
of  the  hypoplastron  forms  a  wall  about  25  mm.  high.  From  the  summit  of  this  there  is  a  slope 
to  the  free  edge. 

The  sulci  of  the  carapace  are  narrow  grooves  with  raised  edges.  The  nuchal  scute  has  a 
width  of  28  mm.  behind,  but  it  is  narrower  in  front.     The  sulci  on  the  bridges  are  directed 

downward  and  forward.  The  vertebral  scutes  have  considerably 
less  lateral  extent  than  do  the  costals.  The  accompanying  table 
presents  in  millimeters  the  greatest  length  and  width  of  the 
vertebrals. 

The  gular  scutes  encroach  on  the  entoplastron.  The  humeral 
scutes  meet  along  the  midline  for  76  mm.;  the  pectorals,  56  mm.; 
the  abdominal,  118  mm.;  the  femoral,  52  mm.;  the  anal,  36  mm. 
Of  the  other  parts  of  the  skeleton  there  are  present  the 
humerus,  the  pelvis,  both  femora,  and  the  right  tibia.  The 
humerus  (fig.  511)  lacks  the  distal  end.  It  was  bent  more  strongly  than  that  of  Gopherus 
polyphemus,  and  the  tuberosities  are  more  strongly  developt.  The  pelvis  is  represented  by 
figs.  512  and  513.  The  ischial  tuberosities  are  pointed,  and  their  apices  are  45  mm.  apart. 
The  extremity  of  the  lateral  and  anterior  pubic  processes  are  missing.  The  ilium  has  the 
proximal  end  much  broadened  antero-posteriorly,  it  being  about  44  mm.  The  femur  (figs. 
514,  515)  is  unusually  straight.     The  digital  fossa  is  rather  deep. 

In  the  Marsh  collection  at  Yale  University  there  is  a  large  specimen  which  is  to  be  referred 
to  this  species.  It  was  collected  for  Professor  Marsh  by  Mr.  J.  B.  Hatcher  in  the  year  1889, 
in  the  Titanotherium  beds  of  South  Dakota.  It  is  at  present  designated  by  the  receipt  numbers 
"2054,  box  I ."  The  specimen  was  flattened  somewhat  during  fossilization,  but  it  was  probably 
originally  of  deprest  form.  Most  of  the  hinder  peripherals  are  now  missing,  as  is  also  the 
plastral  lip.  The  second  neural  of  this  individual  is  octagonal,  but  the  sides  which  are  in 
contact  with  the  first  and  third  costals  of  each  side  are  very  short.  The  third  neural  is  approx- 
imately square.    All  the  others  are  hexagonal.    The  two  suprapygals  are  about  as  in  the  type. 

The  costal  plates  are  strongly  modified,  having  their  proximal 
ends  alternately  narrow  and  wide,  while  the  distal  ends  are 
alternately  wide  and  narrow.  Their  dimensions  are  presented 
in  the  table  herewith. 

The  first  peripheral  has  an  extent,  backward  from  the  free 
edge,  of  50  mm.  The  bridge  peripherals  rise  a  distance  of  88 
mm.  above  the  carina  which  joins  the  free  border  of  the  third 
peripheral  with  that  of  the  seventh.  On  some  of  the  free  periph- 
erals there  is  found  a  mucro,  as  in  the  type  specimen. 


VertebraL 

Length. 

Width. 

I 

86 

102 

2 

go 

go 

3- 

gi 

85 

4 

75 

g2 

5 

90 

'35 

CostaL 

Width 
upper  end. 

Width 
lower  end. 

2 

4' 

82 

3 

44 

46 

•*• 

38 

85 

5 

38 

^5 

6 

35 

55 

7    • 

28 

33 

TESTUDINIDj*. 


405 


The  plastron  shows  no  especial  differences  when  compared  with  that  of  the  type.  The 
apices  of  the  xiphiplastron  are  not  notcht,  in  this  way  differing  slightly  from  those  of  the 
original  specimen. 

No.  238  of  the  Carnegie  Museum,  Pittsburg,  is  a  third  known  specimen  of  this  species. 
It  is  a  complete  shell,  which  was  collected  by  Prof.  J.  B.  Hatcher  from  the  Oreodon  beds  of 
the  Oligocene,  at  Warbonnet,  Sioux  County,  Nebraska.  The  carapace  is  375  mm.  long 
and  325  mm.  wide.     Like  the  other  specimens,  it  is  deprest.    When  compared  with  the  type 

511-  5H-  5«5- 


512-  513- 

Figs.  511-515- — Testudo  latlcunea.     Humerus,  femur,  and  pelvis  of  type.     X  §. 
511.  Proximal  portion  of  left  humerus. 


cig.  Pelvis,  seen  from  left  side.     iV,  ilium; 
isch,  ischium;    pub,  pubis. 


512.  Pelvis,  seen  from  below. 

514.  Left  femur,  dorsal  surface. 

515.  Left  femur,  tibial  border. 


there  appear  to  be  no  important  differences.  The  sulci  run  along  the  summits  of  low  ridges, 
as  in  the  type.  Those  of  the  hinder  peripherals  end  at  the  free  margins  of  the  latter  on  pro- 
jecting points. 

The  only  important  feature  of  the  plastron  is  found  in  the  shape  of  the  anterior  lobe. 
This  is  more  wedge-shaped  than  in  the  type  specimen,  the  convexity  of  the  free  border,  from 
the  axillary  notch  to  the  gulo-humeral  sulci  being  much  less  pronounct.  The  epiplastral  lip 
is  notcht  and  tootht  in  front  like  that  of  the  type. 

Testudo  ligonia  Cope. 

Figs.  516-525. 

Testudo  Ugonius,  CoPK,  Palaeont.  Bull.  No.  15,  p.  6,  1875;  Synop.  New  Vert.  Tert.  Colorado,  1875, 
p.  19;  Ann.  Rep.  U.  S.  Geol..and  Geog.  Surv.  Terrs.,  1873  (1874),  p.  51 1 ;  Vert.  Tert.  Form.  West., 
1884,  pp.  762,  766,  plate  Ixi,  figs.  2,  3. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,   1902,  p.  451. 

This  species  was  based  on  a  single  imperfect  individual,  and  no  others  have  yet  been 
secured.  The  type  belongs  to  the  Cope  collection  in  the  American  Museum  of  Natural 
History  and  bears  the  number  1 148.  It  was  collected  by  Cope  in  1873,  in  the  Oreodon  beds 
of  the  White  River  deposits,  at  the  head  of  Horse  Tail  Creek  in  northeastern  Colorado.  It 
consists  of  a  portion  of  the  nuchal  bone,  the  first  and  probably  the  ninth  right  peripherals, 
the  left  epipla.stron,  a  part  of  the  left  hyoplastron,  and  the  left  hypoplastron  in  the  region  of 


4o6 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


the  inguinal  notch.  Another  peripheral  is  present  which  has  the  same  texture  and  general 
appearance  as  the  other  bones,  but  it  possibly  belongs  to  another  turtle.  If  pertaining  to  this 
skeleton  it  can  be  only  the  eleventh. 


516.  517. 

Figs.  516-518. — Testuioligonia.     Parts  of  carapace  of  type.     Xj. 

516.  First  peripheral  and  part  of  nuchal,     nu.  p,  nuchal  plate;   nu.  s,  nuchal  scute;  per,  i,  first  peripheral. 

517.  Section  of  first  peripheral  near  union  with  second.     Upper  surface  toward  the  left. 

518.  Ninth  peripheral  of  type. 

The  nuchal  (fig.  516)  had  a  length,  in  the  median  line,  of  about  100  mm.;  a  width,  at  the 
free  border,  of  70  mm.;  and  a  maximum  width  of  108  mm.  The  greatest  thickness,  at  the 
midline,  is  21  mm.  The  portion  occupied  by  the  first  vertebral  scute  stands  at  a  distinct  angle 
with  that  in  front  of  it.  The  first  peripheral  has  a  fore-and-aft  extent  of  81  mm.,  of  which  75 
mm.  has  been  exposed  on  the  upper  surface.     The  thickness  of  the  sutural  border  next  the 


519.  522. 

Figs.  519-522. — Testudo  ligoma.     Peripherals  and  epiplast  of  type.     Xj. 
519.  Section  of  ninth  peripheral,  near  union  with  eighth.  520.  Supposed  eleventh  peripheral. 


521 .  Section  of  eleventh  peripheral,  near  union  with  tenth. 


522.   Upper  view  of  left  epiplastron. 


second  peripheral  is  26  mm.    The  free  borders  of  these  bones  are  acute.    Fig.  517  is  a  section 
taken  near  the  articulation  with  the  second  peripheral. 

The  ninth  peripheral  (fig.  518)  is  high  and  narrow,  the  height  being  92  mm.,  the  width 
along  the  free  border  24  mm.  There  is  no  flare,  and  the  free  border  is  acute.  The  greatest 
thickness,  at  a  point  73  mm.  above  the  free  border,  is  24  mm.  Fig.  519  is  a  section  taken  near 
the  anterior  sutural  border.     The  free  edge  is  acute.     If  the  remaining  peripheral  (fig.  520) 


TESTUDINID^:. 


407 


belongs  to  this  specimen  it  must  be  the  eleventh,  and  the  height  of  the  peripherals  was  rapidly 
reduced  from  the  ninth,  inasmuch  as  the  supposed  eleventh  is  only  64  mm.  high.  Its  thickness 
is  26  mm.  The  upper  surface  is  nearly  plane,  while  the  inferior  is  convex  in  section  at  right 
angle  with  the  free  border.  Fig.  521  is  a  section  taken  near  the  posterior  sutural  border.  Cope's 
measurements  indicate  that  he  had  one  other  hinder  peripheral,  but  this  is  not  now  present. 
Curiously  enough,  his  dimensions  apply  exactly  to  the  first  right  peripheral. 

The  sulci  are  narrow  and  sharply  imprest.  The  nuchal  scute  is  40  mm.  long  and  only  9 
mm.  wide.  On  the  lower  side  of  the  bone  this  scute  has  a  posterior  width  of  25  mm.  The 
sulcus  between  the  first  and  second  marginals  is  62  mm.  long.  The  anterior  width  of  the  first 
vertebral  has  been  58  mm. 

Professor  Cope  figured  the  left  epiplastron,  as  seen  from  below;  but  he  erroneously  stated 
that  the  view  is  from  above.  A  figure  is  here  presented  of  the  bone  as  seen  from  above  (fig. 
522).  The  anterior  lip  projects  abruptly  from  the  general  outline  of  the  anterior  lobe  for  a 
distance  of  35  mm.  The  anterior  border  of  the  lip  is  truncate,  with  the  angle  between  it  and 
the  lateral  border  dipt  off.  The  whole  free  edge  of  the  epiplastron  is  acute,  except  near 
the  midline,  where  it  is  slightly  rounded.    From  the  free  edge  of  the  lip  the  bone  thickens 


523-  524- 

Figs.  523-525. — TestuJo  ligonia.     Parts  of  plastron  of  type.     X  i. 


525- 


523.  Fragment  of  left  hypoplastron,  lower  surface,    a,  suture  with  seventh  peripheral;  be,  suture  with  xiphiplastron; 

bdy  suture  with  right  hypoplastron. 

524.  Section  acrossleft  hypoplastron  just  in  front  of  union  with  xiphiplastron.    a,  outer  border;  6,  border  at  midline. 

525.  Fragment  of  hyoplastron.     Shows  suture,  cd,  for  union  with  entoplastron;  pec,  pectoral  scute. 

backward  until  it  attains  a  thickness  of  32  mm.;  then  suddenly  drops  ofl^  to  17  mm.  The 
portion  of  the  epiplastron  in  front  of  the  gulo-humeral  sulcus  projects  nearly  horizontally  for- 
ward, while  the  portion  behind  it  ascends  to  meet  it.  On  the  lower  side  there  is  a  decided 
angle  between  the  two  portions.     The  sulcus  runs  forward  in  this  angle. 

The  fragment  of  hypoplastron  (fig.  523)  extends  from  the  inguinal  notch  to  the  longitudinal' 
median  suture  and  backward  to  the  suture  with  the  xiphiplastron.  The  base  of  the  hinder 
lobe  is  shown  to  have  been  i88  mm.  wide.  From  the  buttress  a  rounded  ridge  (fig.  524) 
descended  which  past  backward  on  the  summit  of  a  wall  surmounting  the  border  of  the 
lobe.  The  outer  face  of  the  wall  is  convex  and  30  mm.  high.  From  the  summit  the  inner  face 
slopes  gradually  to  the  midline.  The  lower  surface  of  this  bone  displays  faint  grooves  on  the 
area  of  the  femoral  scute. 

The  sulci  of  the  plastron,  like  those  of  the  carapace,  are  narrow  and  sharply  imprest. 
The  gular  scutes  encroacht  on  the  epiplastra.  The  humero-pectoral  sulcus  (fig.  525)  crost  the 
midline  about  8  mm.  behind  the  entoplastron.     The  pectorals  are  18  mm.  wide  at  the  midline. 

Under  the  species  T.  quadrata  will  be  found  mention  of  characters  which  distinguish  it 
from  the  present  species. 

Testudo  amphithorax   Cope. 

Figs.  526-531. 

Testudo  amphithorax,  CoPE,  Palaeont.  Bull.  No.  15,  1873,  p.  6;  Synop.  New  Vert.  Tert.  Colorado,  1873, 
p.  19;  Ann.  Rep.  Geol.  and  Geog.  Surv.  Terrs.,  1873  (1874),  p.  51 1;  Vert.  Tert.  Form.  West.,  1884, 
p.  767,  plate  Ixi,  fig.  4. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  451. 

Of  this  species  Cope  possest  portions  of  2  individuals  which  display  the  anterior  lobe  ot 
the  plastron,  and  another  which  lackt  this  lobe.  These  specimens  are  now  in  the  American 
Museum  of  Natural  History.    The  portions  of  the  plastron  which  Cope  figured  are  included 


4o8 


FOSSIL    TURTLES    OF    NORTH    AMKRICA. 


under  the  museum's  No.  1 145,  but  this  author  states  that  the  anterior  lobe  does  not  belong  to 
the  same  individual  as  the  posterior.  No  other  parts  of  the  skeleton  belong  with  these  plastral 
bones. 


526. 


528. 


529. 


Figs.   526-530. — Testudo  amphtthorax.     Portions  of  shell. 


526.  Front  of  carapace.    X^.     No.  1139  A.M.  N.  H.    f.  p.  i,  part  of  first  costal  plate;  «w. /).,  nuchal  plate;  nu.Sy 

nuchal  scute;   per.  i,  part  of  first  costal  plate. 

527.  Lateral  view  of  part  of  shell.     Xj.     No.  1139  A.  M.  N.  H.      c.p.  5,  fifth  costal  plate;   hyo,  hyoplastron; 

/i_y/>o,  hypoplastron;  per.  ^,  per.  jy  per.  11,  fourth,  seventh  and  eleventh  peripherals;  py,  pygal;    spy.  i, 
spy,  2,  first  and  second  suprapygals. 

528.  Rear  of  carapace.    Xj.    No.  1139  A.M.N.  H.    c.p.i,  eighth  costal  plate;    sc,  supracaudal  scute;   spy.  i, 

spy.  1,  first  and  second  suprapygals. 

529.  Plastron.    Xi.    Anterior  half  from  No.  1139  A.  M.  N.  H.;  posterior  half  from  No.  1 147  A.  M.  N.  H. 

530.  Upper  surface  of  anterior  end  of  plastron.    Xj.    No.  1 139  A.  M.  N.  H.     en(,  entoplastron;  c/i/,  epiplastron. 

531.  Upper  surface  of  left  xiphiplastron.    Xj.    No.  1147  A.  M.  N.  H.    aw,  anal  scute;  /tm,  femoral  scute;  hypo, 

hypoplastron;  xiph,  xiphiplastron. 

Another  specimen,  No.  1139,  includes  the  anterior  half  of  the  plastron;  a  little  more  than 
the  right  half  of  the  anterior  rim  of  the  carapace;  a  little  more  than  the  left  half  of  the 
posterior  rim,  together  with  most  of  the  bridge  peripherals  of  that  side  and  the  distal  ends  of 
several  costals;  the  pygal  and  both  suprapygals;  the  greater  portion  of  the  shoulder-girdle; 
and  unimportant  parts  of  the  pelvis.  What  appears  to  be  Cope's  third  specimen  consists  of 
the  hypoplastron  and  the  xiphiplastron  of  the  left  side.    It  has  the  number  1147.    Most  of  the 


TESTUDINIDiE.  4O9 

following  description  is  taken  from  No.  1139.  All  the  known  specimens  were  collected  in  the 
White  River  deposits  (Oreodon  beds),  at  the  head  of  Horse  Tail  Creek,  in  northeastern 
Colorado. 

The  members  of  this  species  appear  to  have  had  a  rather  narrow  and  elongated  shell; 
and  this  was  probably  considerably  elevated.  The  form  was  therefore  somewhat  like  that  of 
Stylemys  oregonensis  or  that  of  the  living  Testudo  tahulata. 

The  length  of  the  carapace  was  close  to  460  mm.,  and  the  width  approximately  300  mm. 
The  anterior  part  of  the  carapace  which  has  been  preserved  (fig.  526)  consists  of  a  portion  of 
the  left  first  peripheral,  nearly  the  whole  of  the  nuchal,  the  first,  second,  and  most  of  the  third, 
right  peripherals,  and  a  part  of  the  first  right  costal.  The  anterior  border  is  somewhat  concave 
along  the  nucha!  and  part  of  the  first  peripheral;  then  it  passes  by  a  broad  curve  into  the  side. 
The  free  edge  of  this  rim  is  subacute,  but  it  is  considerably  roughened.  The  nuchal  is  76  mm. 
wide  along  the  free  border;  126  mm.  in  maximum  width;  and  about  100  mm.  along  the  median 
line.  Its  greatest  thickness  at  the  midline  is  25  mm.  The  border  of  the  first  peripheral  is  y/ 
mm.  long;   that  of  the  second  is  75  mm.     The  anterior  peripherals  are  but  little  flared. 

The  bridge  peripherals  preserved  (fig.  527)  are  part  of  the  fourth,  most  of  the  fifth,  sixth, 
and  seventh.  Each  was  about  50  mm.  wide  and  no  mm.  high.  A  rather  deep  groove  runs 
along  the  side  of  the  shell  just  above  the  lower  ends  of  these  peripherals. 

The  posterior  peripherals  (fig.  527)  and  practically  the  whole  of  the  pygal  (fig.  528)  are 
present.  The  free  edges  of  all  these  are  acute.  The  tenth  and  the  eleventh  flare  slightly. 
The  eighth  is  80  mm.  high;  the  eleventh,  63  mm.  The  thickness  of  each  is  about  22  mm. 
The  inferior  surface  is  convex  in  perpendicular  section.  The  pygal  is  convex  above  in  all 
directions.  The  upper  border  is  80  mm.  wide  and  somewhat  excavated  for  the  second  supra- 
pygal;  the  free  border  is  only  about  25  mm.  wide.  The  thickness  is  17  mm.  The  second 
suprapygal  is  broadly  triangular,  with  a  repand  base.  The  height  is  50  mm.,  the  width  80 
mm.  The  penultimate  suprapygal  (fig.  528)  has  the  usual  bifurcate  form,  with  the  forks 
resting  on  the  eleventh  peripherals.  The  hinder  portion  of  the  carapace  has  sloped  downward 
and  backward  at  an  angle  of  about  45°. 

The  fourth  costal  had  a  width  of  about  60  mm.  at  its  lower  end;  the  fifth,  a  width  of  34 
mm.;  the  sixth,  a  width  of  49  mm.;  the  seventh,  a  width  of  33  mm.;  the  eighth,  a  width  of 
44  mm.    The  costals  have  a  thickness  of  about  8  mm.    No  neurals  have  been  preserved. 

The  sulci  which  limit  the  dermal  scutes  of  the  carapace  are  usually  narrow  and  only 
slightly  imprest,  that  passing  between  the  costals  and  the  marginals  being  broadest  and 
deepest. 

The  nuchal  scute  is  36  mm.  long  and  16  mm.  wide.  The  first  marginal  is  53  mm.  along 
its  anterior  border  and  81  mm.  along  the  hinder,  an  unusual  form.  The  second  is  yy  mm. 
wide  along  the  free  border;  30  mm.  along  the  posterior  border.  The  third  has  a  width  of  6g 
mm.  along  the  free  border.  The  first  vertebral  had  a  width  of  146  mm.  across  the  anterior 
end,  but  narrowed  posteriorly.  The  hinder  end  of  the  fifth  had  a  width  of  about  80  mm. 
Since  most  of  the  median  region  of  the  carapace  is  missing,  nothing  is  to  be  learned  regarding 
the  other  vertebrals. 

The  height  of  the  supracaudal  scute  (fig.  528,  sc)  is  73  mm.;  its  width  100  mm.  Its  upper 
border  rises  on  the  second  peripheral  about  20  mm. 

As  already  stated,  only  the  anterior  half  of  the  plastron  of  No.  1139  is  present.  Nor  is 
there  at  command  any  plastron  which  furnishes  both  the  hinder  and  the  anterior  portions. 
It  is  hence  impossible  to  determine  exactly  the  length  of  this  portion  of  the  shell.  The  length 
of  the  anterior  half  of  No.  1139  (fig.  529,  front  portion),  to  the  hyohypoplastral  suture,  is  238 
mm.  The  length  of  the  hinder  portion  of  the  type  plastron  figured  by  Cope  (fig.  529,  hinder 
portion),  measuring  backward  from  the  hyohypoplastral  suture,  is  256  mm.  This  applied  to 
the  anterior  half  of  I139  would  bring  the  hinder  border  too  close  to  the  pygal  and  therefore 
must  have  belonged  to  a  somewhat  larger  individual  than  the  latter.  About  220  mm.  may  be 
added  to  the  length  of  the  anterior  half  of  1139,  thus  making  its  plastron  458  mm.  long.  This 
implies  that  the  anterior  lip  must  have  projected  somewhat  in  front  of  the  anterior  border  of 
the  carapace,  and  this  conclusion  has  been  reacht  on  other  grounds. 

The  anterior  lobe  of  No.  1 139  has  a  length  of  165  mm.  and  a  width  of  214  mm.  The  free 
edge  is  acute,  except  at  the  midline,  where  it  is  somewhat  rounded.    The  anterior  lip  does  not 


410  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

project  beyond  the  general  border  of  the  lobe.  It  is  truncated  in  front.  The  distance  between 
the  crossings  of  the  gular  sulci  over  the  free  border  is  no  mm.  On  the  upper  side  (fig.  530), 
the  lip  extends  backward  60  mm.,  thickening  until  it  reaches  36  mm.  There  is  no  excavation 
behind  the  thickened  portion.  The  suture  between  the  epiplastrals  is  65  mm.  long.  The 
entoplastron  is  hexagonal,  pointed  in  front,  broad  behind.  The  length  along  the  midline  is 
108  mm.;  its  greatest  breadth  is  104  mm.  The  hinder  lobe  may  be  described  from  Cope's 
type.  In  this  individual  the  hinder  lobe  was  240  mm.  wide  and  143  mm.  long  to  the  ends  of 
the  xiphiplastral  apices.  The  notch  in  the  rear  was  about  76  mm.  wide  and  37  mm.  deep. 
In  the  median  portion  of  this  lobe  the  bone  is  about  15  mm.  thick,  but  at  the  inguinal  notch 
the  thickness  is  42  mm.  Here  the  outer  face  is  almost  perpendicular,  but  it  at  once  begins  to 
slope  inward  and  upward  and  to  diminish  in  height,  so  that  at  the  apices  of  the  xiphiplastra 
the  face  looks  upward  and  the  thickness  is  only  27  mm.  On  these  apices  the  face  is  56  mm. 
wide.  From  the  inguinal  notch  backward  this  face  is  separated  from  the  remainder  of  the 
bone  by  a  rather  sharp  ridge.  This  markt  the  boundary  between  the  skin  and  the  bone 
covered  with  horn.  In  the  case  of  both  the  specimens  furnishing  the  posterior  lobe  there  is  a 
sharp  notch,  about  6  mm.  deep,  at  the  very  apex  of  the  xiphiplastron. 

The  gular  scutes  encroach  on  theentoplastron.  The  humero-pectoral  sulci  pass  close  behind 
it.  The  pectoral  scutes  are  about  20  mm.  wide  at  the  midline;  the  abdominals  about  75  mm.; 
the  xiphiplastrals,  50  mm.     All  of  the  sulci  are  narrow,  but  some  are  rather  deeply  imprest. 

A  portion  of  another  plastron.  No.  1147  (fig.  531),  consisting  of  the  left  hypoplastron  and 
the  left  xiphiplastron,  has  a  length  of  255  mm.  The  horn-covered  surface  on  the  apex  of  the 
xiphiplastron  is  74  mm.  wide. 

The  elements  of  the  right  half  of  the  shoulder-girdle  are  present.  The  scapula  is  about 
105  mm.  long  and  14  mm.  wide  at  the  middle  of  its  length.  The  coracoid  is  75  mm.  long, 
and  its  median  border  is  60  mm.  long.  The  scapula  and  the  procoracoid  process  make  a  little 
more  than  a  right  angle  with  each  other. 

There  are  in  the  American  Museum  of  Natural  History  portions  of  2  shells  from  the  same 
region  as  those  described  above  which  are  referred  with  some  doubt  to  the  same  species. 
They  were  considerably  larger  and  had  thicker  bones.  Other  specimens  still.  No.  1 146  of  the 
same  museum,  collected  on  Old  Woman's  Creek,  Wyoming,  in  White  River  deposits,  may 
belong  to  T .  amphithorax,  but  the  more  characteristic  parts  are  missing.  The  borders  of  the 
hinder  lobe  are  identical  in  form  with  those  of  the  type  specimen. 

Testudo  quadrata  Cope. 

Teit-figs.  531,  533. 

Testudo  quadratus.  Cope,  Vert.  'I'ert.  Form.  West,  1884,  p.  764,  plate  Ixi,  fig.  5. — Hay,  Bibliog.  and  Cat. 
Foss.  Vert.  N.  A.,  1902,  p.  451. 

This  species  is  based  on  the  lip  of  a  plastron  and  a  portion  of  a  nuchal  bone.  Notwith- 
standing the  meager  nature  of  these  materials,  there  can  be  no  question  regarding  the  distinct- 
ness of  the  species.  The  remains  were  collected  by  Cope  in  1873,  in  the  Oreodon  beds  of  the 
White  River  deposits,  at  the  head  of  Horse  Tail  Creek,  in  northeastern  Colorado.  The 
individual  was  evidently  a  large  one.  The  type  specimen  is  in  the  American  Museum  of 
Natural  History  and  bears  the  number  1149. 

The  anterior  lip  (fig.  532)  projected  much  beyond  the  general  outline  of  the  front  lobe. 
The  right  and  left  borders  are  parallel.  The  anterior  border  has  crumbled  away  somewhat, 
except  at  a  point  near  the  midline;  but  it  was  doubtless  truncated,  with  probably  a  slight 
notch  at  the  midline.  The  lateral  and  probably  also  the  anterior  borders  were  acute.  The 
upper  surface  is  slightly  convex,  the  lower  nearly  flat.  Evidently  the  lip  formed  something  of 
an  angle  with  the  ascending  lower  surface  of  the  plastron.  The  hinder  face  of  the  upper 
part  of  the  lip  was  not  excavated. 

What  distinguishes  this  species  from  all  others  of  our  region  is  the  form  of  the  gular  scutes. 
Instead  of  extending  back  on  the  entoplastron,  they  end  at  the  base  of  the  lip  at  a  sulcus 
which  runs  at  right  angles  with  the  midline.  Each  scute  is  therefore  about  square.  The 
following  are  dimensions  of  this  lip:  Length  of  lip  from  gulo-humeral  sulcus,  70  mm.;  width 
of  lip  at  base,  120  mm.;  thickness  at  the  base,  29  mm. 


TESTUniNID^. 


411 


Figs.  532  and  533. — Testudo  quadrata.     Epiplastral  lip  and 
nuchal  of  type.     X  J- 


532.  Epiplastral  lip,  upper  surface. 

533.  Portion  of  nuchal  bone.    c.s.  i,  part  of  first  costal  scute;  m. 

of  first  marginal  scute;  ««.j,  nuchal  scute. 


,  part 


All  of  the  sulci  present  on  the  fragment  are  deeply  imprest. 

The  fragment  of  the  nuchal  (fig.  533)  is  not  very  instructive.  It  comes  to  an  acute  edge 
in  front,  and  thickens  backward  to  31  mm.  Portions  of  3  scutes  are  shown — the  nuchal,  the 
first  peripheral,  and  the  first  vertebral.  The  nuchal  had  a  length  of  41  mm.  Its  width  is 
indeterminable,  but  exceeded  17  mm.  On  the  lower  side  of  the  bone  the  nuchal  scute  was  con- 
siderably wider  than  above. 
Nothing  can  be  determined 
regarding  the  dimensions  of 
the  other  scutes.  The  sulci 
are  deeply  imprest  and  have 
raised  borders. 

In  its  abruptly  projecting 
lip  this  species  resembles  some- 
what T .  ligonia  found  in  the 
same  region.  The  differences 
are,  however,  very  obvious.  As 
seen  from  the  lower  side  of 
the  plastron,  the  gulo-humeral 
sulci  of  T.  ligonia,  departing 
from  the  free  borders  of  the 
epiplastra,  run  backward  and  inward  at  an  angle  of  about  45°  with  the  midline,  to  end  on  the 
entoplastron.  In  T.  quadrata  the  gulo-humeral  sulci  run  across  the  epiplastra  at  a  right  angle 
with  the  midline  and  do  not  touch  the  entoplastron.  In  T.  ligonia  the  lip,  as  seen  on  the  upper 
side,  continues  backward  on  the  epiplastra  a  distance  even  greater  from  a  line  joining  the 
anterior  ends  of  the  gulo-humeral  sulci  than  it  does  in  front  of  this  line.  In  T.  quadrata,  on 
the  contrary,  the  lip  extends  behind  the  line  mentioned  a  very  short  distance. 

Testudo  cultrata  Cope. 

Testudo  cultratus,  CoPE,  Palaeont.  Bull.  No.  15,  1873,  p.  6;   Synop.  New  Tert.  Vert.,  1873,  p.  19;  Ann. 

Rept.  U.  S.  Geol.  and  Geog.  Surv.  Terrs.,  1873  (1874),  p.  511;  Vert.  Tert.  Form.  West,  1884,  pp. 

762,  763,  plate  Ixiii,  figs.  1-3;   Geol.  Surv.  Texas,  3d  Ann.  Rept.,  1891  (1892),  p.  256. 
Testudo  cultrata,  Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  451. 

The  basis  of  this  species  is  said  by  Professor  Cope  to  have  been  two  imperfect  specimens 
found  by  him  in  1873,  in  the  White  River  deposits,  at  the  head  of  Horse  Tail  Creek,  in  north- 
eastern Colorado.  The  level  is  that  of  the  Oreodon  beds,  the  middle  of  the  White  River. 
The  specimens  described  by  this  author  have  not  yet  been  found  in  the  Cope  collection  in  the 
American  Museum  nor  in  the  U.  S.  National  Museum.  For  this  reason,  it  is  thought  best  to 
reproduce  here  Cope's  description. 

Parts  of  two  individuals  of  this  species  were  obtained  by  my  expedition  of  1873. 

This  is  the  smallest  of  the  five  species  of  Testudo,  having  about  the  average  size  of  the  Stylemys 
nebrascensis.  This  is  indicated  by  the  costal  and  marginal  bones  which  accompany  the  portions  of 
plastron  of  both  specimens.  The  width  of  the  lip  at  the  base  is  also  less  than  that  of  any  of  the  other 
species,  but  the  length  and  thickness  are  remarkable  as  compared  with  the  other  dimensions.  The  width 
and  thickness  at  the  base  of  the  lip  are  nearly  equal;  both  dimensions  diminish  to  the  apex,  which  is 
obtusely  acuminate.  The  superior  face  of  the  lip  is  gently  convex  in  both  dimensions.  The  inferior 
surface  is  plane  anteroposteriorly;  transversely  it  rises  to  the  external  edge,  which  is  subacute.  The 
suture  of  the  gular  scutum  is  directed  posteriorly,  giving  the  usual  triangular  form.  The  thickness  of 
the  lip  is  abruptly  reduced  above,  where  the  surface  descends  to  the  mesosternal  bone. 

The  lip  of  one  of  the  specimens  is  fissured  deeply,  in  an  eccentric  manner,  on  both  sides  of  central 
core.  Whether  this  or  the  unfissured  condition  is  characteristic  of  the  species  or  not,  is  uncertain.  It 
appears  to  be  homologous  with  the  dentation  in  the  lip  of  T.  laticuneus. 

The  marginal  bones  are  robust,  and  are  much  thickened  below.  The  edges  of  those  of  the  posterior 
margin  are  acute,  while  those  of  the  anterior  border  are  obtuse,  thus  differing  from  those  of  T.  laticuneus, 
where  they  are  acute.  At  the  points  where  the  dermal  sutures  reach  the  margin,  both  specimens  are 
unfortunately  broken  in  every  instance,  so  that  the  question  of  notches  or  mucros  can  not  be  decided. 
The  costal  bones  are  moderately  thick,  and  alternate  in  width,  narrower  and  wider.    The  dermal  sutures 


412  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

do  not  display  raised  margins.  The  anal  marginal  bone  is  wedge-shaped,  with  the  posterior  margin 
representing  a  truncate  apex.  Its  surface  and  margin  are  convex,  and  the  anterior  sutural  margin  is 
concave. 

A  fragment,  which  is  in  all  probability  the  posterior  lobe  of  the  plastron,  is  characteristic.  It  is 
thick,  and  its  inferior  face  is  somewhat  recurved  posteriorly.  The  outline  of  the  margin  presents  a  pro- 
nounced obtuse  angle,  and  the  edge  is  several  times  abruptly  notched. 

Measurements  of  No.  i. 

Diameter  of  half  of  lip  : 

At  base 

Vertical 0.040 

Transvers*.' 043 

Length   outer  edge 056 

Diameter  second  marginal  from  anal : 

Thickness 019 

Width 030 

Length  free  margin  of  anal 026 

Width  of  anal   above 050 

Thickness  of  a  vertebral  bone 011 

Thickness  of  a  costal  at  middle 009 

Found  by  myself  near  the  head  of  Horse  Tail  Creek,  in  northeastern  Colorado. 

Cope  has  explained  his  fig.  I  as  that  of  the  right  half  of  the  lip  seen  from  above.  Tills  may 
be  correct,  but  it  is  probable  that  it  presents  the  left  half  of  the  lip  seen  from  below. 


P'iGS.  534  AND  535.     Testudo  peragrans.     Skull  of  type.     Xl. 
534.   Upper  surface.  535.   Lower  surface. 


Testudo  peragrans  Hay. 

Figs.  534-538  • 
Testudo  peragrans,  Hay,  Ann.  Carnegie  Mus.,  iv,  1906  (1907),  p.   15,  figs.  1-5. 

The  type  and  at  present  only  known  specimen  of  this  species  is  No.  iioi  of  Carnegie 
Museum,  Pittsburg,  Pennsylvania.  It  was  collected  by  Mr.  Earl  Douglass,  in  1903,  south  of 
McCarty's  Mountain  and  Big  Hole  River  and  north  of  Dillon,  Montana.  There  is  at  present 
some  uncertainty  regarding  the  age  of  the  deposits.  They  may  be  either  Oligocene  or  Lower 
Miocene. 

The  specimen  furnishes  the  damaged  carapace  and  plastron  and  a  nearly  complete  skull. 

The  skull  (figs.  534-536)  lacks  a  part  of  the  palatal  region,  the  occipital  condyle,  and  the 
right  otic  region.  The  lower  jaw  is  so  closely  cemented  in  its  place  that  it  is  thought  best  not  to 
attempt  to  remove  it.  We  are  therefore  unable  to  determine  the  arrangement  of  the  ridges  and 
grooves  of  the  masticatory  surfaces.  There  are,  however,  no  reasons  for  believing  that  the 
species  does  not  belong  to  the  genus  Testudo. 


TESTUDINIDj*. 


413 


The  length  of  the  skull,  from  the  snout  to  the  hinder  border  of  the  exoccipital  near  the 
condyle,  is  50  mm.  To  the  occipital  condyle  the  length  was  from  3  mm.  to  5  mm.  more.  The 
width,  measured  over  the  auditory  chambers,  is  40  mm.  Seen  in  profile,  the  upper  surface  of 
the  skull  is  convex  from  the  snout  to  the  base  of  the  supraoccipital  spine.  The  interorbital 
region  is  12  mm.  wide.  The  zygomatic  arch  is  6  mm.  wide;  the  postorbital  arch,  5.5  mm.  wide. 
The  orbits  are  nearly  circular,  the  diameters  being  15  mm.  The  nasal  opening  is  12  mm.  wide. 
The  premaxillae  project  considerably  beyond  the  anterior  border  of  the  prefrontals.  The 
longest  diameter  of  the  auditory  chamber  is  11  mm.;  the  shortest,  8  mm.  The  width  of  the 
hinder  pterygoid  region  is  12  mm.  A  prominent,  but  rather  obtuse,  ridge  occupies  the  middle 
of  the  palate.     The  stitures  between  the  various  bones  can  not  be  satisfactorily  determined. 

536- 


Pigs.  536-538. — Testudo  peragrans.     Skull  and  shell  of  type. 

536.  Skull,  left  side.    Xi.  538.  Plastron.    X}. 

537.  Shell,  right  side.     X}.     />«r.  1,  first  peripheral;  A^o,  hyoplastron; 

hypOf  hypoplastron;  xiph^  xiphiplastron. 

Altho  the  shell  is  damaged  so  that  little  that  is  satisfastory  can  be  learned  regarding  the 
neural  and  costal  plates  and  the  costal  scutes,  the  general  form  of  the  carapace  and  plastron  are 
well  presented.  The  carapace  (fig.  537)  is  broad,  truncated  in  front,  broadly  rounded  behind, 
and  quite  convex.  The  hinder  third  is  considerably  higher  than  the  middle  and  front  portions, 
and  the  descent  posteriorly  and  over  the  inguinal  notches  is  quite  abrupt.  It  is  possible  that 
this  is  due  to  some  extent  to  distortion  during  fossilization,  but  there  is  no  evidence  of  this. 
The  length  of  the  carapace  is  320  mm.;  the  width,  280  mm.  The  free  borders  in  front  and 
behind  are  acute;  but  the  peripherals  thicken  rapidly  from  the  border,  the  second  reaching  a 
thickness  of  20  mm.;  the  tenth,  a  thickness  of  25  mm. 

As  stated,  the  characters  of  the  neurals  can  not  be  determined.  The  costal  plates  are  alter- 
nately wider  and  narrower,  the  distal  end  of  the  fifth  being  45  mm. wide,  that  of  the  sixth  30  mm. 
The  pygal  is  convex  in  ail  directions,  on  its  hinder,  or  upper,  surface.  It  is  36  mm.  high  on  the 
midline,  54  mm.  wide  above,  28  mm.  wide  along  the  free  border.  Its  upper  border  is  excavated 
to  receive  the  hinder  suprapygal. 

Little  can  be  learned  regarding  the  epidermal  scutes. 

Large  portions  of  the  plastron  (fig.  538)  are  missing.  The  anterior  lobe  is  90  mm.  long; 
150  mm.  wide  at  the  base.    The  epiplastral  lip  is  very  prominent,  projecting  30  mm.  beyond 


414 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


the  ends  of  the  gulo-humeral  sulci.  It  is  truncated  in  front,  with  a  shght  median  notch.  The 
median  and  the  guio-humeral  sulci  run  in  deep  valleys  in  the  bones.  The  width  of  the  lip  is 
66  mm.  at  the  base,  and  it  diminishes  slowly  toward  the  tip.  On  the  upper  side  the  lip  thickens 
until  it  reaches  26  mm.  in  thickness.  This  is  then  suddenly  reduced.  The  gular  scutes  are 
57  mm.  long  on  the  midline.  The  entoplastron  is  missing.  The  bridge  is  127  mm.  wide.  The 
hinder  lobe  is  148  mm.  wide  at  its  base.    The  hinder  end  of  it  is  missing. 

By  its  prominent  epiplastral  lip  this  species  suggests  T .  thomsont  of  the  Oligocene  of  South 
Dakota.  However,  it  is  noted  that,  judging  both  from  the  relative  sizes  of  the  skulls  and  of  the 
common  parts  of  the  plastra,  the  lip  of  T .  peragrans  would  be  over  100  mm.  wide  if  the  animal 
had  attained  the  size  of  the  type  of  T.  thomsont;  whereas  the  lip  of  the  latter  is  only  82  mm. 
wide.  The  skulls  of  the  two  species  differ  in  important  particulars.  That  of  T.  peragrans  is 
much  more  convex  along  the  midline  above,  the  orbits  are  more  nearly  circular,  the  interorbital 
space  is  relatively  narrower  and  the  pterygoid  region  relatively  wider. 


Testudo  vaga  sp.  nov. 

Plate  19,  fig.  5;    text-figs.  ^-^9-547. 

In  the  Cope  collection  of  fossil  reptiles  belonging  to  the  American  Museum  of  Natural 
History  there  are  various  remains  which  belong  to  the  species  here  recognized.  These  were 
collected  for  Professor  Cope  in  1880,  by  Mr.  J.  C.  Isaac,  from  what  are  probably  lower  Deep 

River  deposits,  in  the  vicinity  of  Laramie  Peak,  Wyoming. 
These  remains  belong  to  at  least  three  individuals. 

The  most  important  of  these  specimens  consists  of  many 
fragments  of  the  carapace,  the  nearly  complete  plastron,  the 
nearly  complete  shoulder-girdle,  considerable  portions  of  the 
pelvis,  the  entire  right  femur,  all  of  the  left  femur  except  the 
distal  end,  the  proximal  ends  of  the  tibia  and  fibula,  nearly 
all  of  the  cervical  vertebrae,  and  a  few  of  the  caudal  vertebrae. 
The  catalog  number  of  this  individual  is  1327. 

The  plastron  (fig.  539)  has  a  length  of  381  mm.  The 
length  of  the  anterior  lobe  is  no  mm.;  the  width  at  the  base, 
195  mm.  The  front  terminates  in  a  lip  which  closely  resem- 
bles that  of  T.  niohrarensis  Leidy,  altho  it  does  not  project 
quite  so  prominently.  As  in  the  case  of  Leidy's  species,  the 
hinder  portion  of  this  lip,  on  the  upper  surface  of  the  plas- 
tron, is  deeply  excavated.  The  width  of  the  lip  from  outside 
to  outside  of  the  gular  scutes  is  80  mm.  In  the  midline  there 
is  a  notch  which  is  deeper  than  in  T.  niohrarensis,  as  shown  in 
Leidy's  type.  The  lip  of  another  specimen.  No.  1326,  has  the 
lip  about  as  it  is  in  Leidy's  figure.  The  upper  surface  of  the 
lip  slopes  upward  and  backward  about  50  mm.  to  a  rounded 
edge.  Beneath  this  edge  is  the  excavation  referred  to  above. 
The  greatest  thickness  of  the  lip  is  25  mm.  The  hyoplas- 
trals  are  80  mm.  long  at  the  midline;  the  hypoplastrals,  105 
mm.;  the  xiphiplastrals,  68  mm. 

The  entoplastron  is  rhombic,  68  mm.  long,  74  mm.  wide. 
The  bridge  of  No.  1327  is  175  mm.  wide. 
The  hinder  lobe  of  the  plastron  has  a  length  of  86  mm., 
and  a  width,  at  the  inguinal  notches,  of  185  mm.  It  is  notcht  behind.  At  the  base  the  outer 
face  of  the  hypoplastron  rises  in  a  nearly  perpendicular  wall  28  mm.  high.  From  the 
inguinal  notch  the  wall  diminishes  rapidly  in  height  and  the  outer  face  comes  soon  to  look 
upward  and  outward.    The  inner  face,  at  the  notch,  is  concave. 

The  gular  scutes  have  an  antero-posterior  extent  of  60  mm.  in  the  midline,  and  they  en- 
croach on  the  entoplastron  23  mm.  The  gulo-humeral  sulci  are  about  28  mm.  long  on  the 
upper  surface  of  the  epiplastra,  being  thus  about  one-third  of  the  width  of  the  lip  at  the  base. 
The  humerals  meet  along  the  midline  57  mm.    The  sulcus  limiting  them  behind  is  somewhat 


Fig.  539. — Testudovaga.  Plastron. 
Xi.     No.  1327  A.M.N.  H. 


Neural. 

Length . 

1 

Width. 

H        { 

I 

3' 

2 

21 

33 

''^ 

20± 

23  ± 

4 

22 

36 

5 

■7 

30 

6 

ig 

3^ 

7 

21 

30 

8 

19 

20  ± 

TESTUDINID^.  415 

convex  backward.  The  pectorals  occupy  50  mm.  of  the  midline.  The  sulci  bounding  them 
behind  are  rather  strongly  convex  forward.  The  abdominals  are  large,  joining  along  the 
midline  for  a  distance  of  1 15  mm.  The  femorals  and  the  anals  have  about  the  same  fore-and- 
aft  extent,  40  mm. 

The  fragment  of  the  carapace  of  the  type  individual  has  not  been  freed  from  the  closely 
adhering  matrix. 

In  the  collection  made  by  Mr.  Isaac  there  is  a  specimen  of  a  rather  small  individual,  No. 
1326,  which  furnishes  a  considerable  portion  of  the  carapace  (plate  19,  fig.  5),  as  well  as  the 

characteristic  parts  of  the  plastron.  All  the  neurals  are  repre- 
sented in  whole  or  part,  and  in  the  same  way  are  represented 
most  of  the  costal  plates.  The  dimensions  of  the  neurals  are 
shown  in  the  table. 

The  first  neural  is  broader  behind  than  in  front,  and  there  is 
on  its  anterior  end  a  prominent  boss.  The  second  and  fourth 
neurals  are  octagonal.  The  third  is  represented  by  only  a  part; 
but  it  was  doubtless  quadrangular,  with  the  lateral  borders  con- 
vex. The  fifth  is  hexagonal  and  short.  The  sixth  is  hexagonal, 
with  the  antero-lateral  sides  longer  than  the  postero-lateral;  while 
the  seventh  is  hexagonal,  with  the  antero-lateral  sides  shortest. 
The  eighth  is  hexagonal  and  elongated  fore  and  aft. 
The  costals  of  this  species  are  strongly  modified  as  regards  their  width.  The  third  articu- 
lated with  the  second,  third,  and  fourth  neurals.  It  has  a  proximal  width  of  about  30  mm., 
while  its  distal  end  is  only  16  mm.  wide.  The  fourth  is  very  narrow  at  its  proximal  end,  but 
it  rapidly  increases  in  width,  being  distally  43  mm.  The  fifth  costal  articulates  with  the 
fourth,  fifth,  and  sixth  neurals;  is  28  mm.  wide  proximally  and  15  mm.  distally.  The  sixth  is 
17  mm.  wide  proximally  and  considerably  wider  at  the  distal  end.  The  costals  are  markt  on 
their  distal  halves  with  grooves  and  ridges,  produced  by  the  growth  of  the  scutes. 

The  first  vertebral  scute  had  a  width  of  50  mm.  at  the  anterior  end  and  about  45  mm.  at 
the  hinder  end.  The  third  has  been  66  mm.  wide  at  the  middle  of  its  length;  the  fourth,  53  mm. 
Another  specimen,  brought  from  the  same  region  by  the  same  collector,  had  a  carapace 
about  330  mm.  long.  But  little  of  the  plastron  is  present.  The  carapace  is  crusht  and  various 
parts  are  wanting.  The  number  of  this  individual  is  2894.  This  carapace  is  peculiar  in  having 
the  fourth  neural  hexagonal,  instead  of  octagonal.  The  sixth  costals  expand  distally,  being 
there  40  mm.  and  22  mm.  proximally.  The  seventh  costals  are  narrow,  21  mm.  proximally, 
14  mm.  distally.  The  ninth  peripheral  had  a  thickness  of  11  mm.  The  anterior  vertebral 
scute  had  a  width  of  78  mm.,  while  the  fifth  was  122  mm.  wide. 

All  the  vertebrae  of  the  neck  of  the  type  specimen  (fig.  540)  are  present  except  the  first 
and  second.  On  comparison  with  the  corresponding  vertebrae  of  a  specimen  of  T.  radiata 
whose  plastron  is  two-thirds  as  long,  it  is  found  that  the  neck  of  T.  vaga  wns  relatively  shorter 
than  that  of  the  T.  radiata,  but  the  centra  are  in  size  proportionally  broader.  There  are 
some  differences  in  the  zygapophyses  worthy  of  note.  In  T.  radiata,  the  prezygapophyses  of 
the  sixth  cervical  rise  to  a  height  of  10  mm.  above  the  lower  border  of  the  centrum,  and  the 
zygapophyses  measure  only  4  mm.  each  across  the  articular  surface.  In  T.  vaga  these  prezyg- 
apophyses rise  to  a  height  of  20  mm.  and  are  11  mm.  across.  The  postzygapophyses  of 
the  eighth  cervical  of  T.  radiata  have  a  length  of  7  mm.;  those  of  T*.  vaga  a  length  ot  22  mm., 
a  difference  out  of  all  proportion  to  the  sizes  of  the  two  animals.  The  cervicals  of  the  latter 
are  in  fact  as  large  as  those  of  a  Chelydra  of  the  same  size. 

Herewith  are  furnisht  figures  of  the  scapula  and  the  coracoid  of  the  left  side  (figs.  541, 
542).  These  parts  do  not  differ  in  any  important  way  from  the  same  bones  of  Gopherus 
polyphemus,  altho  they  are  proportionally  stouter.  The  coracoid  is  64  mm.  long  and  6i  mm. 
broad  at  the  inner  end.     The  neck  of  the  bone  is  14  mm.  wide. 

The  vertebral  end  of  the  scapula  is  missing,  so  that  the  length  can  not  be  stated.  Above 
the  glenoid  cavity  the  bone  is  much  comprest.  The  comprest  procoracoid  process  (fig.  541) 
has  a  length  of  60  mm.,  measured  from  the  center  of  the  glenoid  cavity. 

The  humerus  (fig.  543)  resembles  closely  that  of  Gopherus  polyphemus,  altho  stouter  in 
build,  resembling  in  this  respect  that  of  T.  radiata  of  Madagascar.     As  a  portion  of  each  of 


4i6 


KOSSII.    TURTLKS    OF    NORTH    AMERICA. 


the  humeri  is  missing  the  length  of  the  bone  can  not  be  accurately  determined,  but  it  must 
have  been  close  to  95  mm.  The  head  and  the  radial  and  the  ulnar  tuberosities  do  not  differ 
in  any  important  degree  from  those  of  living  species  of  Testudo.  At  the  distal  end  the  radial 
fossa  is  deeper  than  in  any  species  of  Testudo  at  hand.  The  radial  border  is  reduced  to  a 
sharp  edge  and  this  is  perforated  by  the  ectepicondylar  foramen. 

The  individual  No.  1327  furnishes  a  nearly  complete  pelvis  (figs.  544,  545),  no  part  being 
unrepresented  except  the  proximal  ends  of  the  ilia  and  the  processes  extending  backward 
from  the  ischia.  In  general,  the  pelvis  resembles  closely  that  of  G.  polyphemus.  Measured 
from  side  to  side  at  the  upper  border  of  the  acetabula,  the  width  was  about  120  mm.;   from 


541-  545- 

Figs.  540-547.— T^j/u^/o  vaga.    Xh-    No.  1327  A.  M.  N.  H. 


544.  Pelvis,  seen  from  below. 

545.  Pelvis,  left  side.     ;7,  ilium;   isch^  ischium;    puh,  pubis. 

546.  Right  femur,  dorsal  surface. 

547.  Right  femur,  tibial  border. 


540.  Fourth  to  eighth  cervical  vertebra'. 

541.  Left  scapula,  showing  glenoid  fossa  and  articulating  sur- 

face for  coracoid. 

542.  Left  coracoid. 

543.  Right  humerus.    Probably  too  great  space  between  parts. 

the  hinder  border  of  the  ischium  to  the  front  of  the  pubis  the  distance  is  about  58  mm.  The 
ilium  had  a  total  length  of  approximately  70  mm.  Its  upper  end  was  expanded,  and  its 
posterior  plate-like  process  of  bone  is  directed  outward.  In  this  respect  it  resembles  the 
species  of  Testudo  at  hand. 

The  ischium  measured  50  mm.  from  the  center  of  the  acetabulum  to  the  midline.  From 
the  median  suture  the  hinder  border  runs  directly  outward  until  the  processes  are  reacht  on 
which  the  ischia  rest  in  contact  with  the  plastron.  These  appear  to  have  had  their  median 
edge  about  17  mm.  from  the  midline,  and  to  have  been  about  13  mm.  wide.  There  appears  to 
be  much  variation  among  the  various  species  of  Testudo  in  respect  to  the  position  of  these 
processes.  In  G.  polyphemus  and  T.  radiata  they  are  placed  far  outward  toward  the  acetabula; 
in  T.  tabulata,  they  are  much  nearer  together. 

The  angle  made  by  the  symphysis  of  the  ischia  with  the  symphysis  of  the  pubis,  measured 
on  the  upper  surfaces  of  the  bones,  is  very  large,  about  120°,  being  greatly  like  that  of 
T.  radiata.    In  Gopherus  polyphemus  it  is  not  much  more  than  90°.    From  the  point  of  articu- 


TESTUOINID^. 


417 


lation  of  the  pubis  with  the  ischium,  near  the  midline,  to  the  anterior  tip  of  the  pubis  is  39  mm. 
The  lateral  pubic  processes  are  stout,  and  appear  to  have  been  directed  less  strongly  outward 
than  in  any  of  the  species  of  Testudo  named  above.  Where  it  forms  the  anterior  boundary  of 
the  ischio-pubic  foramen,  the  pubic  bone  is  beveled  off  above,  being  in  this  respect  like  that  of 
Gopherus  polyphemus. 

The  femur  (figs.  546,  547)  is  strictly  like  that  of  Testudo,  since  the  greater  and  the  lesser 
'trochanters  are  united  by  a  high  ridge.  This  converts  the  fossa  which  lies  between  the  tro- 
chanters of  the  Emydidae  into  a  pit.  So  far  as  the  materials  at  hand  indicate,  this  pit  is  much 
deeper  in  T .  vaga  than  in  Stylemys  nebrascensts.  The  two  trochanters  rise  to  the  same  level, 
not  quite  to  that  of  the  head  of  the  femur.  On  the  distal  end  of  the  bone,  a  sharply  defined 
ridge  separates  the  condylar  surface  for  the  tibia  from  that  of  the  fibula,  a  condition  that  the 
writer  has  not  observed  in  Testudo.  In  Stylemys  nebrascensts  this  ridge  is  still  better 
developt. 

The  scantiness  of  the  materials  from  which  Leidy's  Testudo  niobrarensis  is  known  makes 
it  diflficult  to  distinguish  it  with  certainty  from  the  species  here  described.  Since  the  two  belong 
apparently  to  very  different  levels  the  probability  is  great  that  they  are  not  identical.  The  lip 
of  Leidy's  species  appears  to  project  further  beyond  the  general  outline  of  the  anterior  lobe 
and  the  length  of  that  part  of  the  gulo-humeral  scute  that  lies  on  the  upper  side  of  the  epi- 
plastral  is  shorter  than  in  T.  'vaga,  one-fourth  the  width  of  the  base  of  the  lip  instead  of  one- 
third.  From  the  younger  specimens  of  T.  oshomiana  it  differs  in  the  great  antero-posterior 
extent  of  the  pectoral  scutes  and  in  the  strong  diflFerentiation  of  the  costal  bones. 


Testudo  inusitata  Hay. 

Plate  68,  figs,  i,  2. 

Testudo  inusitata,  Hay,  Ann.  Carnegie  Mus.,  iv,  1906  (1907),  p.  18,  plates  iii,  iv. 

This  name  is  applied  to  a  specimen  which  was  collected  by  Mr.  Earl  Douglass,  near 
Canyon  Ferry,  Broadwater  County,  Montana.  The  horizon  is  regarded  as  being  that  of  the 
Deep  River.    The  specimen  is  a  shell,  the  right  side  of  which  is  missing.    The  catalog  number 

is  311- 

The  shell  is  convex  above.    The  outline  in  front  and  behind  is  rounded.    The  peripherals 

flare  slightly  over  the  limbs.    The  pygal  is  missing.    The  length  of  the  carapace  is  265  mm.; 

the  width  is  200  mm.    The  nuchal  is  60  mm.  long,  47  mm.  wide  in  front,  65  mm.  where  widest. 

The  first  neural  seems  to  have  been  4-sided.     The  second  to  the  sixth  are  hexagonal.     The 

dimensions  are  given  in  the  accompanying  table. 


Dimensions  of  neurals. 

Dimensions  of  costal  bones.    1     Dimensions  of  costal  scutes. 

No. 

Length. 

Width. 

No. 

Proximal 
width. 

Distal 
width. 

No. 

Length. 

Width. 

7 

35 
l6 

i7 
»S 
z6 
28 
»4 

26 

35 
37 
37 
37 
36 
22 

• 

^9 
29 

22 
»9 
19 
17 
16 

38 
ig 

34 
20 

33 
17 
3» 

45 
50 
57 

50 

5° 

71 
75 

78     1 

70      1 

75 

The  costal  plates  are  alternately  wider  and  narrower  proximally  and  narrower  and  wider 
distally.    Their  dimensions  are  shown  in  the  middle  table  above. 

The  peripherals  over  the  bridges  are  high,  rising  about  65  mm.  above  the  level  of  the 
plastron.    The  free  borders  of  those  in  front  and  those  behind  the  bridges  are  acute. 

The  vertebral  scutes  are  considerably  wider  than  long.  The  lateral  borders  are  not  greatly 
angulated.     The  approximate  measurements  are  shown  above  in  tabular  form. 

The  plastron  has  a  length  of  245  mm.  The  anterior  lobe  is  80  mm.  wide  and  135  mm. 
wide  at  the  base.  The  epiplastral  lip  projects  25  mm.  beyond  the  ends  of  the  gulo-humeral 
27 


^iS  FOSSIL     TURTI.KS    OV    NORTH    AMERICA. 

sulci.  It  is  58  mm.  wide  at  the  base  and  it  narrows  slightly  toward  the  tip.  The  latter  is 
truncated.  From  its  acute  free  borders  the  lip  thickens  rapidly,  rising  on  the  upper  surface 
until  it  attains  a  thickness  of  21  mm.  The  thickening  continues  backward  37  mm.  from  the 
front.  The  entoplastron  is  hexagonal,  49  mm.  long  and  65  mm.  wide  at  the  base.  The  bridge 
is  105  mm.  wide. 

The  hinder  lobe  is  53  mm.  long  on  the  midline,  65  mm.  to  the  hinder  ends  of  the  xiphi- 
plastra.  The  width  at  tfie  base  is  1 1 1  mm.  The  notch  is  43  mm.  wide.  At  the  inguinal  notch 
the  free  border  of  the  hypoplastron  is  22  mm.  thick,  the  outer  face  rising  perpendicularly. 
Further  backward  the  thickness  rapidly  diminishes,  so  that  the  middle  of  the  free  border  of 
the  xiphiplastron  is  acute  and  thin. 

The  gulars  occupy  42  mm.  of  the  midline,  barely  reaching  the  entoplastron.  The  humer- 
als  are  55  mm.  long,  extending  slightly  behind  the  entoplastron.  The  pectorals  occupy  15  mm. 
of  the  midline.  Their  outer  ends  are  greatly  expanded.  The  abdominals  measure  70  mm. 
on  the  midhne;   the  femorals,  25  mm.;    the  anals,  30  mm. 

Much  of  the  outer  surface  of  both  carapace  and  plastron  are  sculptured  strongly  by  the 
lines  of  growth  of  the  epidermal  scutes. 

This  species  presents  the  feature,  unusual  in  TestutJo,  of  having  only  hexagonal  neurals. 
It  thus  resembles  Stylemys;  but  it  differs  from  the  known  species  of  the  latter  in  having  a 
prominent  epiplastral  lip. 

Testudo  farri  sp.  nov. 
Plate  69,  figs.  I,  2;    text-figs.  548,  549. 

A  species  of  Testudo  was  collected  in  the  Deep  River  formation,  of  Smith  River  Valley, 
central  Montana,  in  189 1,  by  a  party  from  Princeton  University.  This  specimen  has  now  the 
catalog  number  10486.  Only  the  shell  is  represented.  This  has  been  considerably  crusht 
downward  and  a  little  toward  the  right  side.  Of  the  carapace  there  are  missing  all  behind  the 
fourth  neural  and  the  fifth  costals,  as  well  as  the  first  three  peripherals  of  each  side.  The  plas- 
tron is  complete. 

While  this  species  resembles  in  many  respects  both  T .  ntohrarensis  Leidy  and  T .  vaga  Hay, 
it  is  evidently  specifically  different  from  both. 

An  estimate,  made  on  comparison  with  Gopherus  polyphemus,  indicates  that  the  total 
length  of  the  carapace  (plate  69,  fig.  1;  text-fig.  548)  was  originally  about  310  mm.    The  width 

was  not  far  from  the  same.  The  nuchal 
bone  is  55  mm.  long  and  74  mm.  wide.  The 
first,  third,  and  fifth  neurals  are  4-sided;  the 
second,  fourth,  and  probably  the  sixth  are 
octagonal.  The  dimensions  of  the  bones 
are  shown  in  the  table. 

The  costal  plates  are  differentiated,  as  is 
common  in  the  genus,  so  that  the  proximal 
ends  are  alternately  wider  and  narrower. 
The  table  shows  the  widths. 

The  fifth  peripheral  has  a  height  of  61  mm. 
The  upper  surface  of  the  carapace  is  strongly  imprest  by  the  lines  ot  growth  ot  the 
epidermal  scutes.  The  sulci  are  distinct.  The  boundaries  of  the  vertebrals  are  straight  lines. 
The  nuchal  scute  is  15  mm.  long  and  7  mm.  wide.  The  first  vertebral  is  54  mm.  long,  90  mm. 
wide  in  front;  the  second  is  56  mm.  long,  55  mm.  wide  in  front,  72  mm.  wide  at  the  middle 
of  the  length;   the  third  is  55  mm.  long,  and  has  a  maximum  width  of  76  mm. 

The  plastron  (plate  69,  fig.  2;  text-fig.  549)  is  273  mm.  long  and  203  mm.  wide.  The 
front  lobe  has  a  length  of  70  mm.  and  a  width  of  134  mm.  at  the  base.  The  lip  projects 
only  moderately  beyond  the  curve  of  the  lobe  behind  the  gular  sulci.  Its  anterior  border  is 
but  little  convex  and  appears  not  to  have  been  notcht.  From  one  gular  sulcus  to  the  other 
the  distance  is  62  mm.  From  the  front  of  the  entoplastron  to  the  tip  of  the  lip  is  23  mm. 
Lookt  at  from  above,  this  lip  extends  backward  a  distance  of  38  mm.,  then  drops  off  abruptly 
to  the  general  level  of  the  upper  surface  of  the  lobe.  The  ledge  thus  formed  is  deeply  exca- 
vated.   The  thickness  of  the  bone  at  the  hinder  end  of  the  lip  is  32  mm.     The  entoplastron 


Dimensions  of 

neurals. 

Dimensions  of  costal  plates. 

-.          Proximal         Distal 

width.           width.     ; 

No.         Length. 

Width. 

1  1          30 

2  ;          32 

26 

4  ^7 

5  29 

27 
43 
34 
45 
35 

2  19                  42 

3  35                 ^^ 

4  .8                 38 

5  35               ^3 

TESTUDINID^. 


419 


is  pyriform,  pointed  in  front,  broadly  rounded  behind.  Its  length  is  60  mm.;  its  greatest 
breadth  also  is  60  mm. 

The  hyoplastral  bones  join  at  the  midline  for  a  distance  of  49  mm.;  the  hypoplastrals,  a 
distance  of  70  mm.;  the  xiphiplastrals,  a  distance  of  46  mm.  The  notch  in  the  rear  of  the 
plastron  is  38  mm.  wide.  The  hinder  lobe  has  a  length  of  70  mm.,  and  a  width  of  140  mm. 
at  the  base. 

The  gulars  are,  taken  together,  58  mm.  wide.  They  overlap  on  the  entoplastron.  The 
humeral  scutes  are  40  mm.  long  on  the  midline;  the  pectorals,  only  12  mm.;  the  abdominals, 
86  mm.;   the  femorals,  40  mm.;   the  anals,  25  mm. 


Figs.  548  and  549. — Testudo  farri.     Carapace  and  plastron  of  type.     X  i- 
548.  Anterior  half  of  carapace.  549.  Plastron. 

The  outer  surface  of  the  plastral  bones  is  somewhat  sculptured  along  the  lines  of  growth 
of  the  scutes.  There  were  large  inguinal  scutes  and  their  areas  are  strongly  imprest  with  the 
growth  lines. 

The  present  species  comes  from  an  earlier  formation  than  that  to  which  T.  niobrarensis 
is  supposed  to  belong.  The  latter  appears  to  differ  in  having  a  more  projecting  epiplastral  lip. 
What  remains  of  the  entoplastron  indicates  that  this  was  relatively  narrower  and  longer  than 
that  of  T.  farri. 

From  T.  vaga,  which  it  resembles,  this  species  is  distinguisht  by  the  much  shorter  union 
of  the  pectoral  scutes  at  the  midline,  12  mm.,  instead  of  50  mm.    There  are  other  differences. 

7 .  osborniana  has  the  union  of  the  pectoral  scutes  still  shorter  than  has  T .  farri.  The 
entoplastron  is  of  a  different  shape  and  the  vertebral  scutes  are  less  angular. 

This  species  is  named  in  honor  of  Dr.  M.  A.  Farr,  of  the  department  of  paleontology  in 
Princeton  University,  Princeton,  New  Jersey. 


Testudo  emilise  sp.  nov. 
Plate  70,  figs.  I,  2. 

The  type  of  this  species  belongs  to  the  American  Museum  of  Natural  History  and  bears 
the  catalog  number  6135.  It  was  found  during  the  summer  of  1906,  by  Mr.  Albert  Thomson 
on  Porcupine  Creek,  South  Dakota.  The  beds  in  which  it  was  found  are  the  Lower  Rosebud, 
a  part  of  the  Lower  Miocene.  The  shell  only  is  present  and  of  this  the  costals  of  the  left  side 
behind  the  fifth  are  missing,  also  the  peripherals  behind  the  left  seventh,  the  pygal,  the  right 
eleventh  peripheral,  and  the  ultimate  and  penultimate  suprapygals. 

The  length  of  the  carapace  (plate  70,  fig.  i)  was  very  close  to  320  mm.  The  extreme  width 
is  255  mm.    The  shell  was  high  and  vaulted  and  apparently  highest  toward  the  rear.    The  out- 


420 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


line  was  truncated  in  front,  broadly  rounded  behind.    On  the  area  of  the  first  vertebral  scute 
is  a  prominent  median  ridge  forming  an  elongated  boss. 

The  nuchal  bone  is  y^  mm.  long,  63  mm.  wide  in  front,  98  mm.  where  widest.  The  first 
neural  is  4-sided;  all  the  others  are  hexagonal,  thus  resembling  those  of  T.  inusitata.  The 
accompanying  table  gives  the  dimensions  of  these  neurals,  of  some  of  the  costals,  and  of  the 
vertebral  scutes. 


The  costal  plates  are  only  slightly  differentiated  as  regards  the  width  of  the  upper  and 
lower  ends. 

The  sulci  are  narrow  and  deeply  imprest.  The  vertebral  scutes  are  wider  than  long  and 
their  sides  are  not  greatly  angulated. 

The  scutal  areas  of  the  carapace  are  more  or  less  strongly  grooved  by  the  lines  of  growth 
of  the  scutes.  The  plastron  (plate  70,  fig.  2)  has  a  total  length  of  290  mm.,  or  273  mm.  along 
the  midline,  the  notch  in  the  rear  being  17  mm.  deep.  The  length  of  the  anterior  lobe  is  95 
mm.;  its  width  at  the  base,  148  mm.  From  the  axillary  notches  it  contracts  gradually  to  the 
gulo-humeral  sulci.  The  lip  is  33  mm.  long,  60  mm.  wide,  with  nearly  parallel  sides.  Its 
anterior  border  is  notcht  at  the  midline  and  slightly  tootht  laterally.  On  the  upper  surface 
the  thickening  of  the  lip  extends  backward  44  mm.  and  the  thickness  becomes  25  mm.  The 
entoplastron  is  51  mm.  long  and  56  mm.  wide.  The  bridge  is  120  mm.  long.  The  hinder  lobe 
is  140  mm.  wide  at  the  base  and  75  mm.  long  to  the  extremities  of  the  xiphiplastra. 

The  gular  scutes  are  40  mm.  long  on  the  midline;  they  lack  16  mm.  of  reaching  backward 
to  the  entoplastron.  The  humerals  occupy  73  mm.  of  the  midline;  the  pectorals,  17  mm.; 
the  abdominals,  83  mm.;  the  femorals,  34  mm.;  the  anals,  22  mm. 

This  species  resembles  closely  T.  inusitata  of  the  Deep  River  beds  of  Montana.  It  differs 
from  that  geologically  later  species  in  having  a  longer  plastral  lip  and  especially  in  the  failure 
of  the  gular  scutes  to  reach  the  entoplastron.  The  femoral  scutes  are  relatively  wider  than 
those  of  the  Montana  species.  The  type  of  the  latter  has  but  seven  neurals;  the  present 
species  has  eight.  In  T.  inusitata  the  widths  of  the  upper  and  lower  ends  of  the  costal  plates 
differ  more  than  in  the  species  here  described. 

This  species  is  dedicated  to  my  wife,  Mary  Emily  Hay. 


Testudo  pansa  sp.  nov. 

Plate  71,  figs.  I,  2;    text-figs.  550,  551. 

This  very  distinct  and  striking  species  was  discovered  by  Mr.  Barnum  Brown,  of  the 
American  Museum  of  Natural  History,  in  the  Pawnee  Creek  beds  of  the  Miocene  of  Colorado, 
in  1 90 1.  The  exact  locality  where  the  type  and  only  specimen  was  found  is  near  the  line 
between  the  states  of  Colorado  and  Nebraska,  north  of  Sterling,  Colorado.  The  number  of 
the  specimen  is  5869. 

The  form  of  the  species  is  rather  peculiar  in  the  genus.  It  is  broad,  deprest,  somewhat 
rounded  in  front,  and  broadly  rounded  behind.  The  plastron  is  extremely  flat.  The  upper 
surface  of  the  shell  passes  abruptly  into  the  lower  surface,  the  free  border  of  the  carapace  in 
front  passing  into  a  lateral  carina  on  each  side,  and  this  again  into  the  free  border  behind. 
The  total  length  of  the  carapace  (plate  71,  fig.  i;  text-fig.  550)  is  775  mm.  The  greatest 
width  is  690  mm.    The  elevation  of  the  carapace  above  the  plastron  is  now  only  250  mm.,  and 


TESTUDINIDiE. 


421 


it  is  probable  that  the  shell  has  suffered  little  depression  during  fossilization.  The  anterior 
peripherals  are  slightly  flared  upward;  the  hinder  peripherals  not  at  all  so.  The  curvature  of 
the  upper  surface  is  everywhere  gentle.  The  species  possesses  unusually  narrow  peripherals. 
The  first  has  an  extent,  at  right  angles  with  the  free  border  of  the  shell,  of  65  mm.  The  sixth 
rises  from  the  lateral  carina  146  mm.  The  eleventh  measures  from  the  free  edge,  at  the  suture 
between  it  and  the  tenth,  to  the  costal  suture,  87  mm.  The  inner  thickening  of  the  anterior 
peripherals  extends  backward  from  the  free  border  about  57  mm.,  and  the  thickness  is  about 
27  mm.  The  inner  thickening  of  the  hinder  peripherals  continues  for  about  75  mm.  from  the 
free  edge,  and  amounted  to  about  30  mm.  The  free  edges  of  the  carapace  are  everywhere 
acute. 

The  nuchal  bone  extends  along  the  border  of  the  shell  118  mm.  and  backward  along  the 
midline  127  mm.  The  forms  of  the  neural  bones  may  be  seen  from  the  figures.  Most  of  them 
are  hexagonal,  but  the  second  and  fourth  are  octagonal.  The  second  and  fourth  costals  are 
narrow  at  their  proximal  ends,  very  broad  at  the  distal.     The  third  and  fifth  are  narrow 


550. 


Figs.  550  and  551. — Testudo  pansa.     Carapace  and  plastron  of  type.     X  j^. 
550.  Carapace.  551.  Plastron. 

distally  and  broad  proximally,  where  they  each  come  into  contact  with  3  neurals.  The  first 
suprapygal  has  the  usual  bifurcate  form,  and  comes  into  contact  on  each  side  with  the  eleventh 
peripheral.  The  second  suprapygal  is  small,  extending  along  the  midline  57  mm.  The  pygal 
measures  52  mm.  on  the  midline,  1 10  mm.  along  the  free  border. 

The  plastron  (plate  71,  fig.  2;  text-fig.  551)  is  very  broad  and  flat.  The  exact  position 
of  the  sutures  between  the  plastral  bones  and  the  peripherals  of  the  bridge  can  not  be  deter- 
mined, but  they  are  not  far,  if  at  all,  mesiad  of  the  sulci  between  the  plastral  and  the  marginal 
scutes.  The  length  of  the  plastron  in  the  midline  is  715  mm.;  to  the  extremities  of  the  apices 
of  the  xiphiplastra,  45  mm.  more.  The  width  of  the  plastron  is  about  580  mm.  The  anterior 
lobe  has  a  length  of  195  mm.,  and  a  width  of  400  mm.  at  the  base.  The  borders  of  the  lobe  are 
acute.  The  anterior  lip  is  narrow  at  the  tip,  very  slightly  notcht,  and  148  mm.  wide  at  the 
gular  sulci.     Superiorly  the  lip  thickens  backward  for  a  distance  of  80  mm.  becoming  about 


422 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


55  mm.  thick.  The  posterior  lobe  is  173  mm.  long  to  the  apices  of  the  xiphiplastra,  and  is  370 
mm.  wide  at  the  base.  The  posterior  notch  is  1 10  mm.  wide  and  45  mm.  deep.  At  the  inguinal 
notch  the  edge  of  this  lobe  forms  a  wall  about  55  mm.  high,  having  a  rounded  outer  face  and  a 
sloping  inner  face.  Posteriorly  the  wall  diminishes  rapidly  in  height,  so  that  the  thickness  at 
the  xiphiplastral  apices  is  only  30  mm. 

The  entoplastron  is  rhombic  in  form,  156  mm.  long  in  the  midline,  195  mm.  wide.  The 
hyoplastra  meet  along  the  midline  for  a  distance  of  176  mm.,  the  hypoplastrals  156  mm.,  and 
the  xiphiplastrals  145  mm. 

The  nuchal  scute  is  about  30  mm.  long  and  wide.  The  marginal  scutes  rise  to  the  sutures 
between  the  peripherals  and  the  costals.     The  supracaudal  scute  seems  not  to  have  been 

divided  in  the  midline.  It  has  a  width  along  the  free  border  of 
200  mm.  The  vertebral  scutes  are  very  wide,  especially  those 
behind  the  first.     The  table  gives  the  dimensions. 

The  gular  scutes  extend  backward  on  the  entoplastron. 
The  humerals  have  an  extent  of  100  mm.  along  the  midline. 
The  pectorals  are  73  mm.  antero-posteriorly  at  the  midline. 
Beyond  this  they  narrow  for  some  distance,  then  expand  greatly. 
The  abdominal  scutes  meet  along  the  midline  a  distance  of 
207  mm.;    the  femorals,  100  mm.;    the  anals,  75  mm. 

The  pelvis  is  preserved  in  position.     It  has  a  stout  lateral 
pubic  process.     The  tubera  ischii  are  conical,  and  their  apices  are  105  mm.  apart. 


Vertebral 
scute. 

Length . 

Greatest 
width. 

I 
2 
3 
4 
5 

160 

'37 
137 
162 
.5s 

.60 

"S 
25o 
200 

227 

Testudo  osborniana  Hay. 

Plates  72-75;  teit-figs.  552-562. 
Testudo  oshorntnna.  Hay,  Ann.  N.  Y.  Acad.  Sciences,  xvi,  IQ05,  p.   ?I2. 

The  type  of  the  present  species  was  secured  in  1901,  by  Mr.  Barnum  Brown,  near  the  line 
between  Colorado  and  Nebraska,  north  of  Sterling,  Colorado.  The  locality  is  in  the  latter 
state.  The  deposits  affording  it  belong  to  the  Miocene,  and  are  known  as  the  Pawnee  Creek 
beds.  The  specimen  belongs  to  the  American  Museum  of  Natural  History,  and  bear  its 
catalog  number  5868.  It  consists  of  a  complete  shell,  the  skull  (lacking  the  lower  jaw),  the 
pelvis,  both  hinder  limbs  nearly  complete,  and  the  tail.  From  the  deeply  concave  plastron  it 
is  concluded  that  the  animal  was  a  male.    The  total  length  of  the  carapace  is  775  mm. 

The  skull  (figs.  552-554)  is  rather  long  and  narrow  for  a  Testudo,  and  the  bones  are  moder- 
ately thick  and  heavy.  The  sides  of  the  skull  are  parallel  from  the  squamosal  processes  to  the 
front  of  the  orbits,  beyond  which  they  converge  with  nearly  straight  outlines  to  the  rounded 
snout.  Seen  from  the  side  the  upper  outline  of  the  skull  is  concave  behind  the  orbits,  above 
and  in  front  of  them  moderately  convex. 

The  following  are  some  of  the  dimensions  of  the  type  skull: 


Millimeters. 
Snout  to  the  end  of  the  supraoccipital  process. .      129 

Snout  to  occipital  condyle 119 

Width  at  the  base  of  the  quadrates 81 

Width  at  the  hinder  end  of  the  maxillae 79 


Millimeters. 

Width  of  interorbital  space 26 

Width  of  nasal  opening  transversely 26 

Antero-posterior  diameter  of  the  orbit 29 


The  height  of  the  skull  from  the  cutting-edge  of  the  maxilla  to  the  upper  surface  of  the 
frontals  is  contained  in  the  length  from  the  snout  to  the  condyle  2.8  times. 

The  prefrontals  meet  along  the  midline  a  distance  of  23  mm.,  and  this  is  also  the  length  of 
the  suture  between  the  frontals.  The  orbits  are  subquadrilateral.  The  long  axis,  30  mm.,  is 
directed  from  the  prefrontal  border  backward,  outward,  and  downward.  The  jugal  arch  has  a 
width  of  16  mm.  The  maxilla  descends  from  the  floor  of  the  orbit  a  distance  of  18  mm. 
The  cutting-edge  is  concave,  especially  posteriorly,  and  is  rather  coarsely  dentated.  The 
squamosal  processes  are  not  laterally  comprest,  but  swollen,  especially  on  the  inner  side;  and 
the  outer,  upper  border  rises  but  little  above  the  upper  surface  of  the  paroccipital. 

The  antero-posterior  extent  of  the  otic  region,  measuring  across  the  paroccipital  and 
prootic,  is  33  mm.  and  contained  in  the  length  of  the  skull  to  the  occipital  condyle  3.6  times. 


TESTUDINID^. 


423 


The  palatal  region  (fig.  553)  is  highly  vaulted,  the  median  fossa  having  a  width  of  23  mm. 
The  narrowest  portion  of  the  pterygoids  is  also  23  mm.  wide.  On  the  outer  border  of  each 
pterygoid  is  a  distinct  ectopterygoid  process.  The  vomer  is  well  archt  upward,  and  is  traverst 
by  a  longitudinal  ridge,  which  is  sharp  in  front,  but  rounded  behind.  The  masticatory  surface 
of  the  maxilla  presents  2  longitudinal  ridges  and  2  deep  grooves.  The  outer  and  principal 
ridge  is  separated  from  the  descending  cutting-border  of  the  jaw  by  the  wider  groove.  This 
ridge  is  received  in  the  groove  of  the  mandible.  The  ridge  is  sharp,  slightly  tootht,  and  runs 
forward  and  inward  to  the  premaxilla,  then  directly  forward  on  the  latter  bone  to  its  cutting- 
edge.    The  inner  ridge  is  low,  flat,  and  rather  broad,  especially  behind.    It  occupies  the  inner 


552- 


Figs.  552  and  553. — TestuJo  oshnrniana.      Skull  of  type.      X  S- 
552.  Upper  surface.  553.  Lower  surface. 

border  of  the  maxilla.  There  is  no  ridge  occupying  the  midline  along  the  symphysis  of  the 
premaxillae;  hence  this  species  can  not  be  regarded  as  a  Gopherus.  The  masticatory  ridges 
of  the  right  and  left  sides  are  separated  by  a  deep  longitudinal  groove.  This  is  interrupted  only 
by  a  rough  eminence  on  the  hinder  ends  of  the  premaxilla.  The  cutting-edge  of  the  maxilla 
descends  much  below  the  roof  of  the  mouth. 

In  many  respects  this  skull  resembles  that  of  7^.  gilberti;  but,  as  shown  under  that  species, 
T.  osborniana  has  a  much  broader  iugal  arch,  a  more  elongated  otic  region,  a  squamosal  region 
less  comprest  laterally,  and  a  more  heavily  constructed  skull. 

The  carapace  is  high  and  swollen,  resembling  in  general  form  the  shell  of  T.  radiala,  of 
Madagascar.     The  following  table  presents  the  dimensions  of  the  carapace  and  plastron. 


Millimeters. 

Total  length  of  carapace 775 

Width  of  carapace 555 

Height  of  shell 430 

Length  of  plastron 710 


Millimeters. 

Width  of  anterior  lobe 425 

Length  of  anterior  lobe 2!o 

Width  of  posterior  lobe 355 

Length  of  posterior  lobe. 180 


The  carapace  ("plate  72;  text-figs.  555,  556,  557)  is  truncated  in  front,  broadly  rounded 
behind.  The  sides  overhang  the  borders  of  the  plastron.  The  nuchal  and  the  anterior  periph- 
erals are  flared  upward.  The  ninth  and  tenth  peripherals  are  also  somewhat  flared;  the 
eleventh  and  the  pygal  are  nearly  vertical.  The  free  borders  of  the  carapace,  both  in  front  and 
behind,  are  acute. 


424 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


The  nuchal  bone  occupies  140  mm.  of  the  free  border  and  is  182  mm.  wide  at  the  widest 
portion;  141  mm.  long  in  the  midline.  Its  greatest  thickness  at  the  midline  is  36  mm.  The 
bridge  peripherals  are  very  high,  about  230  mm.  and  therefore  nearly  as  high  as  the  costals, 
the  fourth  of  which  is  257  mm.  high.  The  thickness  of  the  inner  surface  of  the  hinder  periph- 
erals increases  to  about  half  of  the 
height  and  is  then  suddenly  reduced, 
the  maximum  being  about  23  mm. 
The  pygal  is  80  mm.  wide  at  the 
free  border,  114  mm.  at  the  upper 
border  and  83  mm.  high  in  the  mid- 
line. Its  thickness  at  the  midline  is 
24  mm. 

The  second  costal  is  70  mm.  wide 
near  the  proximal  end,  88  mm.  at 
the  distal  end.  The  third  is  100  mm. 
Fig.  554.— fw/wfl'o  oshorniana.     Skull  of  type,  ^;je  at  the  proximal  end,  70  mm.  at 

right  side.     X  §.  the  distal  end.    The  fourth  has  a 

width  of  68  mm.  at  the  proximal  end,  90  at  the  distal  end.  The  fifth  has  the  dimensions  respec- 
tively 83  mm.  and  76  mm.  The  sixth  is  73  mm.  wide  proximally,  102  distally.  The  seventh  is 
48  mm.  across  the  proximal  end,  93  across  the  distal.  It  is  seen  from  these  figures  that,  as 
in  other  species  of  festudo,  the  costals,  omitting  the  first,  are  alternately  widened  and  nar- 
rowed proximally,  whilst  alternately  narrowed  and  widened  at  the  distal  ends.  The  degree 
of  differentiation  among  the  costals  is,  however,  less  than  is  usual  in  the  genus. 
The  neural  bones  have  the  dimensions  given  in  the  table  below. 

The  first  suprapygal  is  93  mm.  long  at  the  midUne,  40  mm.  wide  at  the  upper  end,  and 
183  mm.  at  the  lower,  the  bone  having  the  usual  notch  in  its  lower,  or  hinder,  border.  The 
second  suprapygal  has  a  median  length  of  69  mm.  and  a  width  of  92  mm. 

The  vertebral  scutes  are  large,  the  dimensions  being  shown  in  the  table. 
The  nuchal  is  small,  being  27  mm.  wide  at  the  anterior  end,  1 1  mm.  at  the  hinder  end,  and 
52  mm.  long.    The  supracaudal  scute  is  225  mm.  from  side  to  side,  and  has  a  height  of  102  mm. 

The  anterior  lip  of  the  plastron  (plate  '/2,', 
text-fig.  556)  is  greatly  developt.  At  its  base, 
where  the  sulci  bounding  the  gular  scutes 
cross  the  free  border,  the  width  of  the  lip  is 
205  mm.  The  front  of  the  lip  is  slightly  notcht 
in  the  midline.  From  this  the  subacute 
border  curves  round  to  the  base  of  the  lip. 
From  the  free  border  the  bone  thickens  rap- 
idly backward  for  a  distance  of  135  mm.  until 
it  reaches  a  thickness,  in  the  midline,  of  75 
mm.  The  thickness  then  drops  suddenly  off 
to  that  of  the  greater  portion  of  the  plastron. 
The  escarpment  of  bone  thus  formed  is  very 
slightly  excavated.    The  free  border  of  the  anterior  lobe  behind  the  lip  is  acute. 

The  hinder  lobe  of  the  plastron  has  a  wide  shallow  notch  behind.  The  width  of  the  notch 
is  130  mm.;    its  depth  is  only  23  mm. 

The  entoplastron  is  153  mm.  fore  and  aft,  and  210  mm.  wide.  The  hyoplastra  extend 
140  mm.  along  the  midline;  the  hypoplastra,  160  mm.;  and  the  xiphiplastra,  127  mm.  The 
free  border  of  the  hinder  lobe  is  subacute.  From  the  border  the  bone  thickens  rapidly.  Toward 
the  inguinal  notch  the  border  rises  and  forms  a  wall  which  reaches  a  height  of  80  mm.  Its 
summit  is  narrow,  and  the  slope  on  the  mesial  side  is  abrupt. 

The  gular  scutes  occupy  170  mm.  of  the  midline;   the  humerals,  100  mm.;   the  pectorals 

only  10  mm.;    the  abdominals,  255  mm.;    the  femorals,  76  mm.;    and   the  anals,  85  mm. 

The  pelvis  is  in  its  natural  position  and  is  complete,  except  that  the  anterior  processes 

ofthepubes  are  missing.    The  processes  on  the  hinder  border  of  the  ischia  resemble  those  of 


Dimensions  of  neurals. 

Dimensions  of  vertebrals. 

No. 

Length. 

Width. 

No. 

Length. 

Width. 

I 

IIZ 

67 

I 

163 

187 

2 

73 

112 

2 

150 

■85 

3 

70 

103 

3 

'33 

203 

4 

79 

121 

4 

165 

.65 

5 

57 

'OS 

5 

.85 

^35 

6 

61 

95 

7 

51 

85" 

g 

70 

70 

testudinidt*;. 


425 


T.  radtata,  except  that  they  are  relatively  thinner,  the  hinder  border  is  sharp,  and  they  lie  in 
a  plane  which  passes  thru  the  acetabula.  The  distance  between  the  points  of  these  processes 
is  130  mm.  The  upper  surface  of  the  ischia,  in  the  midline,  is  deeply  excavated.  The  process 
on  the  under  side  of  each  ischium  which  rests  on  the  plastron  is  55  mm.  wide,  and  rather  flat 
below  and  behind. 

The  limbs  of  this  tortoise  were  of  the  short  and  heavy  type,  like  those  of  T.  radiata,  of 
Madagascar.  Fig.  558  shows  the  left  femur  seen  from  the  hinder,  or  ventral,  surface.  The 
length  is  144  mm.  The  surface  of  the  bone  is  strongly  imprest  for  the  insertion  of  muscles. 
The  head  is  large,  its  greatest  width  being  58  mm.,  and  the  distance  from  the  uppermost 
border,  when  in  position,  to  the  lower  surface  of  the  ridge  joining  the  trochanters  is  y^  mm. 
The  notch  separating  the  greater  from  the  lesser  trochanter  is  very  shallow,  as  is  likewise  the 
intertrochanteric  fossa.    The  shaft  is  comprest  at  the  middle  of  the  length,  the  perpendicular 


555- 


556. 


Figs.  555  and  556. — Testudo  osbomiana.     Carapace  and  plastron  of  type.     X  J. 
555.  Carapace.  556.  Plastron. 

diameter,  when  the  femur  is  in  its  natural  position,  being  30  mm.,  the  horizontal  diameter 
22  mm.  The  epicondyles  are  strongly  developt.  The  diameter  of  the  bone  through  these  is 
64  mm.     The  condyles  join  each  other  by  a  strongly  developt  groove. 

As  is  to  be  seen  from  fig.  559,  the  tibia  {tib)  is  stout.  Its  length  is  100  mm.;  the  diameter 
through  the  tuberosities  at  the  proximal  end  is  45  mm.  The  diameter  of  the  shaft  between  the 
middle  and  the  distal  thirds  is  18  mm. 

The  fibula  (fig.  559,  fib)  is  88  mm.  long  and  20  mm.  broad  at  the  proximal  end,  and  27  mm. 
at  the  distal  end. 

The  bones  of  the  tarsus  and  toes  are  somewhat  disturbed  and  some  are  missing.  The 
fibulare  (fig.  559)  evidently  coalesct  with  the  astragalus  to  form  the  astragalo-calcaneum. 
The  articular  surfaces  for  the  tibia  and  fibula  are  strongly  concave,  and  their  boundaries  are 
sharply  markt.  This  bone  measures  from  one  side  to  the  other  42  mm.  Distally  there  is  on 
the  tibial  side  a  long  convex  articular  surface  for  those  tarsals  of  the  second  row  which  support 
the  first,  second,  and  third  digits.  On  the  fibular  side  is  a  deeply  concave  surface  for  the 
fourth  tarsal  of  the  second  row. 


426 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


All  the  tarsalia  of  fig.  559  (2,  3,  4,  5,  of  the  second  row)  are  present  in  the  right  foot 
except  the  first;  but  this  is  present  in  the  left  foot.  The  first  and  the  fifth  are  largest.  By  its 
inner  border  the  fifth  articulates  with  the  fifth  tarsal;  and  by  a  part  of  the  lower  border,  with 
the  fourth  metatarsal.  The  metatarsals  of  the  first  and  second  digits  and  the  first  phalangeal 
of  the  second  digit  are  missing;  but  these  are  present  in  the  left  foot.  The  distal,  claw-bearing 
phalanges  are  relatively  long,  that  of  the  first  digit  being  27  mm.  long;  that  of  the  second,  35 
mm.;  that  of  the  third,  40  mm.;  and  that  of  the  fourth,  37  mm.  Each  claw  phalange  is  there- 
fore as  long  as,  or  longer  than,  the  remaining  phalanges,  together  with  the  metatarsal  of  the 
same  digit.     In  size  and  form  the  distal  phalanges  resemble  those  of  Gopherus  polyphemus. 

The  terminal  portion  of  the  tail  is  greatly  expanded.  This  portion  is  75  mm.  long  and 
appears  to  consist  of  5  vertebrae.     The  lateral  processes  of  these  vertebrae  are  lengthened,  so 


557- 
Pigs.  557  and  558. — Testudo  oshorntana.     Shell  and  femur  of  type. 
557.  Carapace,  side  view.      Xi-  5^8.  Left  femur,  ventral  surface.      Xi* 


558- 


that  a  broad  flat  beaver-like  paddle  is  produced.  Its  greatest  breadth  is  85  mm.  The  terminal 
vertebrae,  10  in  number,  of  G.  polyphemus  have  their  lateral  processes  similarly  lengthened, 
but  in  this  case  the  processes  are  distinct,  true  caudal  ribs. 

This  tortoise  possest  the  same  kind  of  supplementary  armor  that  we  have  found  in  7". 
orthopygia.  The  skin  of  the  bottoms  of  the  feet,  of  the  lower  leg,  of  the  hinder  part  of  the 
thigh,  the  tail,  both  on  the  upper  and  the  lower  sides,  and  probably  also  of  the  anterior  limbs 
supported  an  armor  composed  of  bones  of  various  sizes.  These  bones  doubtless  lay  each 
beneath  a  horny  scale  such  as  we  see  protecting  the  limbs  of  many  of  the  living  species  of 
Testudo  and  of  other  genera  of  turtles.  Fig.  559  represents  the  dermal  bones,  as  well  as  the 
foot  bones  of  the  right  hind  foot.  The  dermal  bones  evidently  belonged  to  the  bottom  of  the 
foot  and  the  hinder  portion  of  the  lower  leg.  The  deeper  surface  of  these  bones  is  seen,  as  is 
indicated  by  the  pitting.  The  external  surfaces,  where  seen,  are  smooth.  In  the  figure  the 
tarsal  bones  and  the  phalanges  are  lettered.  It  will  be  observed  that  the  dermal  bones  of  the 
foot  and  the  heel  are  larger  than  those  further  up  on  the  leg.  How  far  up  on  the  leg  they 
extended  is  uncertain. 

Fig.  560  shows  the  dermal  bones  which  protected  the  upper  surface  of  the  tail  and  of  the 
hinder  portions  of  the  thigh.  In  the  center  of  the  mass  is  seen  a  considerable  area  consisting 
of  about  a  dozen  bones  closely  articulated  suturally.  These  overlie  the  expanded  extremity 
of  the  tail,  of  which  the  last  centrum  and  its  processes  (fig.  560,  A.  A)  are  seen  resting  on  the 
hinder  border  of  the  carapace.    On  the  left  side  of  the  figure  the  dermal  bones  adjoining  the 


TESTUDINID^. 


427 


tail  armor  are  larger  than  on  the  right  side,  aitho  they  diminish  in  size  outward.  Ail  these  have 
a  smooth  and  flat  surface,  which  is  undoubtedly  the  exterior.  At  the  extreme  left  border  (fig. 
560,  B)  appears  a  large  pyramidal  bone,  with  an  approximately  square  base.  No  doubt  this 
represents  a  spur  such  as  is  seen  on  the  hinder  side  of  the  thighs  of  many  living  species  of 
Testiido.    The  letter  C  of  fig.  560  points  to  the  corresponding  spur  of  right  side. 

On  the  right  side  of  the  figure  the  bones  are  seen  to  be  rough  and  pitted,  and  the  surface 
is  very  convex.  This  is,  doubtless,  the  inner  surface,  which  has  become  exposed  by  a  flap  of 
the  skin  of  the  thigh  falling  inside  out  over  the  skin  nearer  the  tail.  The  spur  of  this  side  is  seen 
below  this  layer  of  bones.  A  portion  of  the  tail  nearer  its  base  is  present,  and  this  bears  on  its 
upper  surface  a  layer  of  dermal  bones  in  their  natural  position. 

No  portions  of  the  anterior  limbs  are  present. 

A  second  specimen  (plate  74)  of  this  species  was  found  in  the  same  beds  and  same  locality 
in  1901  by  Dr.  F.  B.  Loomis,  of  Amherst  College.  This  specimen  now  bears  the  number 
5870  of  the  American  Museum.    At  the  time  of  its  entombment  this  specimen  was  doubtless 


559.  560. 

Figs.  559  and  560. — Testudo  oshorniana.     Right  hind  leg  and  tail  of  type.     Xi- 

559.  Right  hind  leg.    aj/c,  astragalo-calcaneum;  ^6,  fibula;  mia.  5,  mta.  4,  third  and  fourth  metatarsals;  tih,  tibia; 

/,  //,  ///,  IV y  the  first  to  fourth  digits;   2,  3,  4,  5,  tarsal  bones  of  the  second  row. 

560.  Armor  of  bones  in  the  skin  around  and  on  the  tail.    AAj  extremities  of  the  transverse  processes  of  the  last  caudal 

vertebrse;   5,  left  lateral  spur;    C,  right  lateral  spur. 

uninjured,  but  thru  the  weathering  of  the  matrix  within  a  short  time  before  its  discovery, 
the  region  of  the  left  hind  leg  was  exposed  and  this  limb  is  now  missing,  as  well  as  a  part  of 
the  carapace  near  it.    The  terminal  phalanges  of  the  left  forefoot  also  are  wanting. 

It  appears  probable  that  this  individual  perisht  while  hibernating.  The  head  is  with- 
drawn within  the  shell,  so  that  the  tip  of  the  snout  is  at  a  distance  of  95  mm.  from  the  anterior 
border  of  the  carapace.  The  right  foreleg  is  placed  so  as  to  close  the  shell  neatly  on  that  side. 
The  left  foreleg  is  advanct  slightly.  The  right  hind  leg  is  withdrawn,  so  as  to  shut  in  its 
side  of  the  gap  between  the  upper  and  lower  portions  of  the  shell.  The  broad  armored  tail 
filled  up  the  space  between  the  two  hinder  legs. 

The  skull,  the  cervical  vertebrae,  and  some  other  bones  give  evidences  of  having  been 
considerably  softened  at  some  time  after  death. 


428 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


The  length  of  the  carapace  ot  this  individual  is  930  mm.;  the  greatest  breadth,  690  mm. 
Thru  pressure  of  the  overlying  matrix  the  carapace  is  somewhat  deprest,  so  that  the  form 
of  the  shell  is  best  shown  by  the  type  of  the  species.  The  length  of  the  plastron  is  840  mm. 
The  anterior  lip  projects  hardly  as  much  as  in  the  type,  a  smaller  individual. 

This  specimen  displays  beautifully  the  armor  of  the  forelegs.  A  closely  compacted  layer 
of  bony  nodules  was  imbedded  in  the  skin,  from  the  bases  of  the  claws  to  the  middle  third  of 
the  upper  arm  bone.  Along  the  ulnar  side  of  the  forearm  is  a  row  of  larger  nodules,  one  of 
which  appears  to  have  been  formed  by  the  co-ossification  of  two  originally  distinct  bones. 
Some  of  the  larger  nodules  appear  at  the  elbow  joint.  Above  this  the  nodules  decrease  in  size. 
The  palm  of  the  hand  was  protected  by  a  layer  of  bones  of  moderate  size.  Beyond  the  bones 
forming  the  armor  of  the  foot  projected  the  five  claws. 

The  hind  foot  possest  a  sole  of  bony  nodules,  but  those  bones  shown  in  the  figure  near  the 
claws  are  the  phalanges.  Toward  the  hinder  border  of  the  foot  the  nodules  become  larger 
and  the  two  hindermost  project  as  great  spurs.  Such  bony  spurs  armed  with  a  covering  of 
tough  horn  would  doubtless  offer  some  discouragement  to  any  carnivorous  animal  that  might 
have  sought  entrance  in  that  region.  Perhaps  also  these  spurs  would  be  of  assistance  to  the 
animal  in  walking  over  a  rocky  surface.  Another  great  spur  lies  alongside  the  fourth  claw 
phalange  and  simulates  a  fifth  claw.  In  the  type  specimen.  No.  5868,  the  fifth  tarsal  bone  of 
the  second  row  shows  an  articular  surface  for  a  rudimentary  metatarsal. 

The  tail  presents  in  general  the  same  features  as  that  of  the  type  specimen.  The  central 
nodules  are  still  more  intimately  consolidated.  The  lower  border  of  the  armor  covering  the 
tail  was  apparently  140  mm.  wide,  and  was  bordered  by  about  10  nodules,  which  increase  in 
size  from  the  midline  each  way.  The  outer  3  are  pointed.  It  was  probably  just  outside  of 
these  that  the  armor  of  the  tail  past  into  that  covering  the  thighs.  In  this  specimen  this  armor 
is  continued  two-thirds  the  distance  to  the  knee-joint.  On  each  side  of  the  tail  are  two  very 
large  and  pointed  spurs,  such  as  we  find  on  the  thigh  of  various  living  species  of  Testudo;  but 
these  in  T .  oshorniana  appear  to  have  been  placed  nearer  the  tail  than  usual.  In  the  type 
specimen  there  appears  only  one  spur  on  each  side  of  the  tail. 

The  scapula  and  its  proscapular  process  are  slenderer  than  those  of  T .  impensa.  The 
type  of  the  latter  has  a  carapace  only  a  few  millimeters  shorter  than  the  specimen  of  T.  oshorn- 
iana here  described.    The  table  presents  the  dimensions  of  certain  parts  of  the  two  species. 


Measurements  taken. 

Diameter  of  procoracoid  process  at  middle  of  length: 

Greater 

Smaller 

Length  of  coracoid  from  glenoid  to  median  border  . . . 

Length  of  median  border  of  coracoid 

Length  of  humerus  from  middle  of  head  to  distal  end  . 

Least  diameter  of  shaft 


Testudo 

Testudo 

impensa. 

oshorniana. 

43 

3' 

27 

^3 

'55 
'45 

■45 
■  65 

240 
41 

140 
38 

The  ulna  is  hidden  beneath  the  armor.  The  right  radius  is  exposed  sufficiently  to  permit 
determination  of  the  length.    This  amounts  to  135  mm. 

The  skull  of  this  individual  was  considerably  macerated  about  the  time  of  burial;  the 
bones  have  been  more  or  less  fractured  and  sometimes  slightly  displaced.  One  important  differ- 
ence is  shown  between  it  and  the  skull  of  the  type;  namely,  the  interorbital  space  is  much 
broader.  In  the  type  this  space  is  28  mm.  wide;  in  the  one  now  described  it  is  43  mm.  Ordi- 
narily this  difference  would  be  regarded  as  indicating  a  distinct  species.  Here  we  have  prob- 
ably a  difference  due  to  sex.  The  type  is  almost  certainly  a  male,  as  is  shown  by  the  very 
concave  plastron.     The  other  individual  has  a  very  flat  plastron  and  was  probably  a  female. 

The  cervical  vertebrae  are  all  present.  The  elements  of  the  first  are  hidden  beneath  the 
supraoccipital  process.  The  second  has  been  damaged  so  badly  that  little  can  be  said  regarding 
it,  but  the  posterior  end  appears  to  have  been  concave.  The  third  seems  to  have  had  a  convex 
anterior  end.  Its  posterior  end  is  concave.  The  fourth  has  the  anterior  end  convex.  The  con- 
tiguous ends  of  the  fourth  and  fifth  are  injured,  but  it  seems  pretty  certain  that  the  hinder  end 
of  the  fourth  was  convex  and  the  anterior  end  of  the  fifth  concave.    The  sixth  is  concave  in 


TESTUDINID^. 


429 


front,  convex  behind,  with  two  distinct  surfaces,  forming  a  ginglymoid  joint.  The  seventh  has 
both  ends  concave.  The  eighth  has  a  ginglymoid  concavity  in  front,  and  a  rounded  head 
behind.     The  dorsal  vertebrx  have  all  been  destroyed. 

The  pelvis  of  T .  osborniana  appears  to  have  been  narrower  than  that  of  T .  tmpensa,  the 
width  of  the  former,  taken  across  the  pubes  from  the  lower  border  of  one  acetabulum  to  that 
of  the  other,  being  172  mm.;  in  the  latter  species,  195  mm. 

Besides  the  large  individual  described  above,  Dr.  Loomis  discovered  several  others  of 
smaller  sizes.  One  of  these.  No.  6080,  has  a  carapace  400  mm.  long  and  335  mm.  wide. 
Another  has  the  carapace  266  mm.  long  and  218  mm.  wide.  The  shell  is  complete  and  only 
slightly  distorted.  It  is  numbered  5871  and  is  one  of  five  which  were  piled  closely  together. 
Two  of  these  were  too  much  injured  to  be  worth  saving.  These  shells  appear  to  have 
drifted  to  their  place  of  burial,  for  there  were  no  remains  of  other  bones  of  the  skeleton  with 


561. 


P'iGS.  561  AND  562. — Testudo  osborniana.     Carapace   and   plastron   of  young   individual. 

Xj.     No.  5871  A.  M.  N.  H. 


561.  Carapace. 


562.  Plastron. 


them.  No.  5871  furnishes  figs,  i,  2,  of  plate  75;  and  text-figs.  561  and  562.  In  form  the 
younger  individuals  diflFer  from  the  adults  in  being  more  rounded  in  front,  the  angles  at  the 
third  peripherals  not  having  yet  been  developt.  The  peripherals  of  the  bridge  region  are  not 
so  high  relatively  as  in  the  adults. 

The  plastron  of  No.  5871  (text-fig.  562)  has  a  total  length  of  253  mm.  The  anterior  lobe 
is  67  mm.  long  and  142  mm.  wide  at  the  base.  The  lip  is  62  mm.  wide  at  the  base  and  is 
slightly  notcht  in  front.  The  upper  surface  is  like  that  of  the  larger  specimens.  The  bridges 
are  125  mm.  wide.  The  posterior  lobe  of  the  plastron  is  60  mm.  long  and  130  mm.  wide  at  the 
base.    It  is  broadly  notcht  behind. 

A  still  smaller  individual  found  by  Dr.  Loomis  is  numbered  5873.  It  furnisht  a  shell  only 
slightly  damaged  and  not  at  all  crusht,  so  that  in  it  we  have  the  form  of  the  young.  The  shell 
is  high  and  tumid.  The  peripherals  above  the  bridge  and  the  distal  halves  of  the  costals  are 
ornamented  with  longitudinal  grooves  and  ridges,  which  mark  the  growth  of  the  horny  scutes. 
This,  like  the  other  younger  individuals,  has  a  low  boss  on  the  first  neural  bone. 


43° 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


This  species  differs  from  T.  undata  Cope  in  that  the  posterior  peripherals  do  not  have  a 
strong  recurvature  outward  and  the  internal  thickening  is  much  below  the  border  joining  the 
costal  bones.  From  T .  kletttana,  based  on  a  pygal  bone,  it  differs  in  not  having  the  right  and 
left  borders  parallel,  but  diverging  upward.  The  upper  border  is  notcht  for  the  second  supra- 
pygal.  From  T .  orthopygia  it  differs  in  having  a  more  elongated  skull,  a  broader  plastral  lip, 
and  the  posterior  peripherals  less  abruptly  curved  upward  near  their  free  border. 

The  front  of  the  plastron  of  the  younger  specimens  of  this  species  bears  considerable  resem- 
blance to  the  same  part  oi  T .  tiiobrarensis  figured  by  Dr.  Leidy  (Cont.  Ext.  Vert.  Fauna  West. 
Terrs.,  1873,  p.  225,  plate  iii,  fig.  4).  It  appears  however  that  the  lip  of  Dr.  Leidy's  specimen 
projects  farther  beyond  the  points  where  the  sulci  on  each  side  of  the  lip  cross  the  border  of  the 
plastron,  about  two-thirds  of  the  lip  extending  beyond  these  points.  In  the  specimens  of  T. 
osborniana  at  least  half  of  the  lip  is  behind  these  points,  and  usually  more  of  it.  Only  in  the 
type  specimen  is  there  half  of  the  lip  in  front  of  the  line  joining  the  points  referred  to.  In 
Leidy's  species,  moreover,  the  front  border  of  the  entoplastron  falls  behind  the  ledge  formed  by 
the  lip;  whereas,  in  T.  osborniana  the  front  of  the  entoplastron  is  slightly  in  front  of  the  ledge 
of  the  lip.    Dr.  Leidy's  species  almost  certainly  belongs  to  a  different  geological  level. 

Of  this  fine  species,  which  has  been  named  in  honor  of  Prof.  Henry  F.  Osborn,  of  the 
American  Museum  of  Natural  History,  there  are,  in  the  museum  mentioned,  specimens  which 
give  us  a  knowledge  of  the  whole  osteology  and  of  various  stages  of  growth. 


563- 


564. 


565- 


Figs.  563-565. — Testudo  arenwaga.     Pygal  and  eleventh  peripheral  of  type.     X  i- 

563.  Pygal,  eleventh  peripheral,  and  part  of  suprapygal. 

564.  Section  of  pygal  and  suprapygal  along  midline. 

565.  Section  of  eleventh  peripheral  at  union  with  tenth. 


Testudo  arenivaga  Hay. 

Figs.  563-565. 
Testudo  arenivaga,  Hay,  Ann.  Carnegie  Mus.,  iv,  igo6  (1907),  p.  16,  figs.  6-8. 

The  present  species  is  based  on  a  fragmentary  individual  which  belongs  to  the  Carnegie 
Museum,  Pittsburg,  Pennsylvania.  The  catalog  number  is  150Q.  The  remains  were  found  in 
1905,  in  beds  regarded  as  belonging  to  the  Lower  Miocene  formation.  The  locality  is  about 
2  miles  north  of  Agate  Springs  quarry,  in  Sioux  County,  Nebraska.  The  pygal  and  the  eleventh 
peripheral  are  selected  for  description. 

The  pygal  (figs.  563, 564)  has  a  height,  from  the  free  border  to  sulcus  crossing  the  hinder- 
most  suprapygal,  of  112  mm.  The  width  at  the  upper,  or  anterior,  border  is  102  mm.;  at  the 
free  border,  58  mm.    The  upper  border  is  deeply  notcht  for  the  last  suprapygal,  the  distance 


TESTUDINID^. 


4.?  I 


from  the  free  border  to  the  notch  being  only  83  mm.  The  thickness  of  the  border  which  articu- 
lated with  the  eleventh  peripheral  is  30  mm.  The  exterior  surface  of  the  bone  is  rather  strongly 
convex  both  from  side  to  side  and  from  above  downward.  The  inferior  surface  is  concave 
from  side  to  side,  convex  from  above  downward.  The  free  border  is  acute.  In  fig.  564  the 
inferior  or  inner  surface  is  that  toward  the  left  hand. 

The  portion  of  the  posterior  suprapygal  remaining  indicates  that  the  width  of  this  bone 
was  about  60  mm.     It  is  20  mm.  thick. 

The  eleventh  peripheral  (figs.  563,  565)  is  narrow  above,  widening  below.  The  height  is 
98  mm.;  the  width  of  the  upper  border,  45  mm.;  that  of  the  free  border,  87  mm.  The  exterior 
surface  next  the  pygal  is  nearly  plane;  that  near  the  tenth  peripheral  strongly  concave  up  and 
down,  the  free  border  here  being  considerably  flared  upward.  Fig.  565  is  a  view  of  the  end  ot 
the  bone  which  joined  the  tenth  peripheral.  The  greatest  thickness  is  31  mm.  About  37  mm. 
below  the  upper  border  of  the  bone  the  thickness  is  rather  suddenly  reduced,  forming  a  shoulder 
on  the  inner  side  of  the  bone.    The  upper  border  is  only  13  mm.  thick. 

It  is  necessary  to  compare  these  bones  with  the  corresponding  ones  of  various  other  species 
of  Testitdo. 

They  resemble  most  the  pygal  and  the  eleventh  peripheral  of  T .  impensa.  The  dimen- 
sions of  the  pygal  of  the  latter  species  are  as  follows:  Height,  145  mm.;  width  above,  146  mm.; 
width  along  the  free  border,  90  mm.  It  will  be  seen  that,  relatively  to  the  height,  the  width  is 
greater.  The  exterior  surface,  too,  is  less  convex  in  all  directions.  The  eleventh  peripheral  of 
T.  impensa  measures  as  follows:  Height,  122  mm.;  width  above,  80  mm.;  at  the  free  border, 
123  mm. 

T.  oshornimia,  type,  has  the  pygal  no  mm.  high;  113  mm.  wide  above;  80  mm.  wide  on 
free  border.  It  will  be  observed  that  the  lower  border  is  relatively  considerably  wider.  The 
outer  surface  is  likewise  considerably  less  convex  than  that  of  T .  arentvaga.  The  eleventh 
peripheral  of  T.  oshorniana  has  a  height  of  105  mm.;  a  width  of  66  mm.  along  the  upper 
border;  and  a  width  of  106  mm.  along  the  free  border.  The  two  bones  have  therefore  quite 
different  proportions. 

The  pygal  of  T .  pansa  is  of  a  different  form,  being  wider  below  than  above,  and  not  so  high 
as  wide. 

T.  undata  has  the  hinder  peripherals  more  strongly  flared  upward  than  are  those  of  the 
present  species.     According  to  Cope  the  pygal,  too,  is  flared  upward  toward  the  free  edge. 

Especially  is  it  to  be  compared  with  T .  edce  of  the  same  beds.  The  type  of  the  latter  is  a 
much  smaller  individual.  The  table  presents  measurements  of  parts  common  to  the  two  species. 


Measurements  taken. 


Height  of  pygal  to  lower  border  of  suprapygal . 

Width  of  upper  border  of  pygal 

Width  of  lower  border  of  pygal 

Greatest  thickness  of  pygal 

Height  of  eleventh  peripheral 

Width  of  upper  border  of  eleventh  peripheral  .  . . . 
Width  of  free  border  of  eleventh  peripheral 


Testudo 

Testudo 

ed». 

arentvaga. 

45 

85 

70 

102 

43 

58 

>5 

30 

45 

98 

12 

45 

4» 

87 

It  will  be  observed  that  the  width  of  the  pygal  of  T.  arentvaga  is  less  compared  with  the 
height  than  in  the  case  of  T.  edte.  Again,  the  eleventh  peripheral  of  T.  arentvaga  is  consid- 
erably broader  in  comparison  with  the  pygal  than  is  the  case  with  these  bones  in  T.  edtt. 
The  differences  in  the  proportions  of  the  bones  of  the  two  species  is  well  brought  out  by 
making  plots  with  the  measurements  given,  those  of  T.  arentvaga  being  divided  by  2. 


Testudo  impensa  sp.  nov.     ' 

Plates  76,  77;  text-figs.  566-571. 

The  dry-land  tortoise  to  which  the  above  name  has  been  given  was  discovered  by  Mr. 
Albert  Thomson,  of  the  American  Museum  of  Natural  History,  in  1902,  in  the  Loup  Fork 
Miocene  deposits  of  Montana,  a  short  distance  above  the  mouth  of  the  Madison  River.  The 
locality  is  in  Broadwater  County.    The  number  of  the  specimen  is  5867.    The  parts  represented 


432  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

are  the  skull  complete,  the  nearly  complete  shell,  both  shoulder-girdles,  the  left  humerus,  the 
pelvis  complete,  3  injured  cervical  and  4  caudal  vertebrae,  and  a  quantity  of  dermal  bones. 

The  individuals  of  this  species  appear  to  have  reacht  a  large  size,  the  length  of  the  cara- 
pace of  the  type  being  922  mm.  Their  relationships  were  close  to  T .  osborniana,  as  shown 
both  in  the  skull  and  the  shell. 

The  skull  (figs.  566-568)  lacks  most  of  one  of  the  posterior  lateral  angles.  There  has 
occurred  some  crushing  and  distortion  of  the  prefrontal  region.  The  skull  is  slightly  broader 
in  proportion  to  its  length  than  in  T .  osborniana.  In  the  latter  species  the  width  is  68  per  cent, 
of  the  length  to  the  occipital  condyle,  while  in  T.  impensa  it  is  72  per  cent.  This  small  diiFer- 
ence  may  disappear  on  the  examination  of  other  specimens.  The  following  are  the  principal 
dimensions  of  the  skull: 

Millimeters.  Millimeters. 

Total  length  of  the  skull 157  Width  of  palatal  fossa 39 

Length  to  occipital  condyle 138  Length  of  the  mandible 98 

Width  at  the  quadrates 97  Depth  of  mandible  at  the  symphysis. ...      21 

Interorbital  space 38 

The  prefrontals  meet  along  the  midline  21  mm.;  the  frontals,  27  mm.  The  orbit  is  some- 
what distorted,  but  its  antero-posterior  diameter  is  34  mm.  The  width  of  the  jugal  arch  appears 


566. 


Figs.  566  and  567. — TestuJo  impensa.     Skull  of  type.     X  i- 
566.  Upper  surface.  567.  Palatal  surface. 

to  have  been  about  i6  mm.  The  maxilla  descends  below  the  floor  of  the  orbit  22  mm.  The 
cutting-edge,  seen  from  the  side,  is  convex  in  front,  slightly  concave  posteriorly,  but  the  con- 
cavity seems  to  have  been  less  than  in  T.  osborniana,  and  the  bone  did  not  terminate  posteriorly 
in  such  a  prominent  process  as  in  the  latter  named  species.  This  cutting-edge  is  irregularly 
dentated,  especially  in  front.  The  antero-posterior  extent  of  the  otic  region,  measured  across 
the  paroccipital  and  the  prootic,  is  31  mm.,  being  contained  in  the  length  of  the  skull  to  the 
occipital  condyle  4.45  times.  The  lateral  angles  of  the  skull  extend  behind  the  occipital 
condyle  about  10  mm.  In  T.  osborniana  they  extend  but  little  beyond  the  condyle.  The 
portion  of  the  skull  in  front  of  the  postfrontals  equals  one-half  of  the  length  to  the  condyle. 
In  T.  osborniana  the  portion  mentioned  equals  only  0.45  of  the  length. 

The  nasal  opening  has  a  width  of  30  mm.  The  prefrontals  lack  27  mm.  of  coming  to  a 
perpendicular  from  the  front  of  premaxillae.  In  T.  osborniana  the  prefrontals  lack  only  10  mm. 
of  reaching  this  perpendicular. 


TESTUDINID^. 


433 


The  roof  of  the  mouth  (fig.  567)  resembles  closely  that  of  T.  osborniana.  The  outer  ridge 
of  the  masticatory  surface  is  strongly  developt  and  dentated.  Anteriorly  it  continues  forward 
on  the  premaxilla  of  its  side;  so  that  between  the  right  and  left  ridges  there  is,  in  the  pre- 
maxillary  region,  a  deep  furrow.  The  inner  ridge  of  the  masticatory  surface  is  broad  and 
rough  behind  and  divided  by  a  deep  longitudinal  groove.  The  palate  is  deeply  excavated.  On 
each  pterygoid  there  is  a  hookt  ectopterygoid  process.  The  distance  across  the  two  pterygoids 
is  30  mm. 

The  lower  jaw  (figs.  568,  569)  is  large  and  heavy.  Its  length  from  the  symphysis  to  the 
angle  is  98  mm.;  its  height  at  the  coronoid  process,  32  mm.;  at  the  symphysis,  21  mm.  Each 
ramus  has  its  masticatory  surface  divided  longitudinally  by  a  deep  groove.  From  the  outer 
cutting-edge  sharp  ridges  run  down  on  the  outer  face  of  the  dentary. 

The  total  length  of  the  shell  is  922  mm.;  the  width,  725  mm.  The  height  can  not  be 
exactly  determined,  on  account  of  injuries  to  the  carapace  (plate  76).  The  middle  region  of 
this  has  been  broken  in,  and  the  fragments  considerably  disturbed,  while  the  unbroken  portions 
of  the  costals  and  to  some  extent,  the  peripherals,  have  been  somewhat  deprest.    It  appears, 


568. 


569. 


Figs.  568  and  569. — Testudo  impensa.     Skull  and  lower  jaw  of  type.     X  i. 
568.  Skull,  right  side.  569.  Lower  jaw,  seen  from  above. 

however,  improbable  that  the  shell  ever  had  as  great  height  as  that  of  T.  osborniana.  The 
width  of  the  carapace  is  78  per  cent,  of  the  length;  whereas,  in  T.  osborniana  the  width  is  71 
per  cent.  The  peripherals  have  practically  the  same  form  as  in  the  last-mentioned  species, 
but  those  of  the  bridge  regions  do  not  appear  to  have  had  relatively  as  great  height.  Neither 
do  the  peripherals  of  the  posterior  region  descend  so  steeply  as  in  T.  osborniana.  In  the  latter 
the  pygal  and  the  adjoining  peripherals  slope  forward  from  the  perpendicular  only  about  15° 
or  20°;  whereas,  in  T .  impensa  the  forward  slope  is  about  45°.  A  part  of  this  angle  is  due 
possibly  to  depression,  but  this  seems  improbable.  The  anterior  outline  of  the  carapace  is 
convex,  not  straight  or  concave  as  in  T .  osborniana;  and  the  anterior  border  does  not  pass  so 
abruptly  into  the  lateral  border. 

On  account  of  the  crushing  in  of  the  upper  part  of  the  carapace,  it  has  been  difficult  to 
determine  the  dimensions  of  the  neurals,  but  the  following  statements  may  be  relied  on.  The 
first  neural  (fig.  570)  is  oval  in  form,  and  the  width  has  been  close  to  70  mm.  The  second  is 
octagonal,  and  had  a  width,  where  greatest,  of  120  mm.  The  third  is  hexagonal,  73  mm. 
long  and  97  mm.  wide.  The  fourth  is  octagonal,  76  mm.  long,  112  mm.  wide.  The  sixth  is 
hexagonal,  70  mm.  long  and  100  mm.  wide.    The  seventh  is  63  mm.  long  and  118  mm.  wide. 

The  third  and  the  fifth  costals  are  expanded  at  their  proximal  ends  and  each  is  in  con- 
tact with  three  neurals. 

The  pygal  is  145  mm.  wide  at  its  upper  end,  1 14  mm.  at  the  free  border.  The  first  supra- 
pygal  has  the  usual  bifurcate  form  and  is  in  extensive  contact  with  the  pygal  and  the  eleventh 
peripherals.     The  second  suprapygal  is  90  mm.  long  and  84  mm.  wide. 

The  plastron  (plate  yy;  text-fig.  571)  has  a  total  length  of  805  mm.  The  width,  from  the 
outer  border  of  the  hyoplastron  of  one  side  to  that  of  the  other,  is  650  mm.  There  is  a  con- 
siderable concavity  in  the  region  between  the  inguinal  notches.  The  width  of  the  anterior 
28 


434 


Fossil.    TURTLKS    OK    NORTH    AMERICA. 


lobe  is  470  mm.,  its  length  230  mm.  The  anterior  lip  projects  well  beyond  the  crossing  ot  the 
gular  sulci.  It  does  not  pass  beyond  the  carapace;  whereas,  in  T .  osborniana  the  lip  projects 
beyond  the  carapace  about  80  mm.  The  lip  is  185  mm.  wide  at  its  base  and  nearly  as  wide  in 
front.  It  is  nearly  flat  below,  convex  above,  and  thickens  backward  on  the  upper  surface  to  a 
thickness  of  60  mm.  The  posterior  face  of  this  thickened  portion  is  somewhat  excavated. 
The  whole  free  border  of  the  anterior  lobe  is  acute. 

The  posterior  lobe  has  a  width  of  475  mm.  and  a  length  of  200  mm.  The  notch  is  broad 
and  shallow,  its  width  being  165  mm.,  its  depth  only  30  mm.  At  the  inguinal  notch  the  border 
of  the  hinder  lobe  presents  a  wall  85  mm.  high,  with  a  perpendicular  outer  face  and  a  sloping 
inner  one.    The  wall  diminishes  rapidly  in  height  backward,  so  that  the  thickness  of  the  apices 


570. 


571- 


KlGS.  570  AND  571. — Testudo  impensa.     Carapace  and  plastron  of  type.     X  ». 
570.  Carapace.  571.  Plastron. 

of  the  xiphiplastra  is  only  34  mm.  The  structure  of  this  region  is  greatly  like  that  of  T.  osborn- 
iana. The  entoplastron  is  rhombic,  175  mm.  on  the  midline,  230  mm.  in  transverse  extent. 
The  suture  between  the  two  hyoplastra  is  160  mm.  long;  that  between  the  hypoplastra,  175 
mm.;  that  between  the  xiphiplastra,  145  mm. 

The  first  vertebral  scute  is  250  mm.  wide  in  front.  The  second  is  180  mm.  wide;  the 
third  is  137  mm.  long  and  200  mm.  wide;  the  fourth,  166  mm.  wide;  the  fifth,  210  mm.  long 
and  300  mm.  wide.  The  gular  scutes  lap  over  on  the  entoplastron.  The  humeral  scutes  join 
along  the  midline  for  175  mm.  The  pectoral  scutes  are  very  narrow  at  the  midline,  only 
about  15  mm.,  but  their  outer  ends  expand  greatly.  The  abdominal  scutes  occupy  275  mm. 
of  the  midline;  the  femorals,  75  mm.;  the  anals,  96  mm. 

The  scapula  is  a  large  and  stout  bone.  Its  upper  end,  for  union  with  the  first  costal, 
extended  above  the  glenoid  cavity  a  distance  of  162  mm.    Near  this  upper  end  the  bone  is  38 


TESTUDINID^. 


435 


I'"iG.  572. — Testudo  impensa.     Pelvis  of  type,   Xj.     From  below. 


mm.  thick.  At  the  middle  of  the  glenoid  cavity  the  bone  is  54  mm.  wide  and  40  mm.  thick. 
The  procoracoid  process  extended  beyond  the  middle  of  the  glenoid  cavity  a  distance  of  133 
mm.  The  coracoid  is  short  and  broad.  Each  of  the  borders  was  about  130  mm.  long,  measur- 
ing the  anterior  and  the  posterior  from  the  glenoid  cavity. 

The  humerus  has  a  total  length  of  250  mm.;  the  head,  a  diameter  of  58  mm.;  the  shaft, 
where  narrowest,  a  diameter  of  42  mm.    The  distance  across  the  condyles  is  8g  mm.    The 

angle  between  the  radial  and 
ulnar  processes  is  about  as  in 
Gopherus  polyphemus.  The 
trochlear  surface  is  not  grooved. 
There  is  an  ectepicondylar 
groove,  but  it  does  not  end  in 
a  foramen. 

The  lateral  extent  of  the  pel- 
vis, from  the  lower  end  of  one 
ilium  to  that  of  the  other,  is  276 
mm.  The  total  height  is  220 
mm.  The  upper  ends  of  the 
ilia  are  damaged.  The  ischta 
have  the  posterior  processes 
rather  slender  and  directed  out- 
ward and  backward.  The  lat- 
eral process  of  each  pubis  is 
short,  broad,  and  rounded  on 
the  lower  end.  The  ischiopubic 
foramen  is  nearly  circular. 
Differences  among  the  limb-bones,  shoulder  and  pelvic  girdles  of  this  species  and  of  T. 
oshorniana  are  noted  in  the  description  of  the  latter  species. 

The  few  cervical  vertebrae  present  offer  no  novel  characters.  The  caudals  have  lateral 
processes  which  are  about  35  mm.  long  and  directed  outward  and  backward.  It  appears 
probable  that  the  end  of  the  tail  was  expanded  and  supported  a  shield  of  dermal  bones,  as  in 
T.  orthopygia  and  T.  oshorniana. 

The  dermal  bones  present  are  of  various  sizes  and  forms.  The  most  of  them  have  a  base 
which  is  roughened  and  has  evidently  been  buried  in  the  skin.  The  opposite  surface  is  usually 
smooth  and  forms  a  very  deprest  cone,  the  apex  of  which  overhangs  the  base.  This  smooth 
surface  was  doubtless  covered  with  horn.  These  bones  were  probably  concealed  in  the  skin 
of  the  legs.  They  vary  in  diameter  from  20  mm.  to  25  mm.  Two  larger,  more  pointed  bones, 
measuring  from  base  to  apex  35  mm.  to  40  mm.  and  having  a  base  of  25  mm.  or  more  diameter, 
probably  formed  the  cores  of  spurs  on  the  hinder  parts  of  the  thighs.  Other  bones,  flat  and 
broad,  with  some  of  the  sides  straight  or  nearly  so,  are  suturally  united ;  and  these  in  all 
probability  formed  parts  of  a  caudal  shield,  as  in  the  species  referred  to  above  in  speaking  of 
the  caudal  vertebrae. 

Testudo  undata  Cope. 

Fig.  573- 

Testudo  undata.  Cope,  Ann.  Rept.  Chief  Engineers,  1875,  p.  995  {of  separata  p.  74);  Wheeler's  Rept. 
on  Surv.  W.  looth  Merid.,  iv,  1877,  p.  28^,  plate  Ixvii,  figs.  I,  2. — Hay,  Amer.  Geologist,  xxiv, 
1899,  p.  349;   Bibliog.  and  Cat.  P^oss.  Vert.  N.  A.,  1902,  p.  452. 

Testudo  undata  was  found  in  the  Loup  Fork  deposits  of  the  Miocene,  in  New  Mexico, 
by  Professor  Cope,  in  1874.  The  species  is  based  on  the  pygal  and  7  hinder  peripherals,  all 
somewhat  damaged.  These  specimens  are  in  the  U.  S.  National  Museum,  with  the  number 
2127.  It  is  believed  to  be  best  to  reproduce  here  Cope's  description  and  the  most  instructive 
part  of  his  figure  i,  of  the  plate  cited  (fig.  573). 

The  specimen  which  furnishes  the  characters  of  the  Testudo  undata  includes  portions  or  wholes  of 
8  marginal  bones  and  i  costal.  The  former  display  a  strong  recurvature  outward,  and  their  internal 
thickening  is  near  their  sutural  union  with  the  costals.    The  borders  are  acute  and  do  not  display  any 


4^6  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

emargination  at  either  the  dermal  or  osseous  sutures.     The  posterior  part  of  the  margin  of  the  poste- 
rior marginals  is  very  convex  or  flared  upward,  descending  at  or  behind  the  osseous  suture.    Thus  the 

free  edge  has  an  undulating 
form.  The  caudal  marginal 
bone  is  recurved,  not  prom- 
inent, and  with  a  regular 
i  7  '  '    \  \  1  ifk  \  entire  free  margin.     Its  lat- 

perU\  \     F"  ■     v^        \ — ,^     eral  sutures  expand  forward, 

Py  /  i  V  \-i-''  so  that  its  margin  is  narrower 

than  its  anterior  portion.     It 
is  not  divided  by  a  dermal 
Fig.  S7i-—Testudo  undata.     Pygal  and  hinder  peripherals  of  the  type.      ^"'"''^  consistently  with  its 
X  I     Above  the  pygal  is  a  section  of  the  tenth  peripheral.  generic  character.   The  sur- 

faces  of  the  bones  are  nearly 

smooth.  The  scutal  sutures  are  wide,  and  have  distinctly-defined  borders.   The  marginal  near  the  bridge 

is  remarkably  massive,  the  bridgeward  suture  being  twice  as  thick  as  that  joining  the  free  marginal. 

The  size  of  the  Testudo  undata  is  as  great  as  that  of  any  of  the  species  of  land-tortoises  of  our 

Tertiary  formations. 

Measurements. 

Meter. 
Length  of  the  free  margin  of  three  consecutive  posterior  marginal  bones. .  .  .    0.310 

Length  of  the  last  marginal  bone 122 

Width  of  the  last  marginal  bone 135 

Thickness  at  the  middle 017 

Thickness  of  the  bridgeward  suture  of  a  lateral  marginal .040 

Thickness  of  the  opposite  suture  of  the  same .015 

Fragments  of  other  specimens,  probably  of  this  species,  present  still  larger  proportions. 

As  compared  with  the  two  described  species  of  Stylemys,  this  species  differs  in  the  strong  flaring 
and  recurvature  of  its  marginal  bone,  and  is  the  more  wedge-shaped  caudal  marginal  bone,  as  well 
as  its  much  larger  size. 

To  Cope's  description  may  be  added  the  following:  The  thickness  of  the  anterior  sutural 
border  of  the  eighth  peripheral,  where  it  joined  the  seventh,  is  38  mm.  The  border  which 
joined  the  ninth  peripheral  is  22  mm.  thick.  The  eleventh  peripheral  is  122  mm.  along  the 
free  border;  and  was  about  70  mm.  along  the  upper  border.  Its  greatest  thickness  is  23  mm. 
The  intermarginal  sulci  descend  on  low  broad  elevations  of  the  surface  and  these  elevations 
are  more  pronounct  as  the  free  border  of  the  peripheral  is  approacht. 

Testudo  klettiana  Cope. 

Fig-  574- 

Testudo  klettiana,  CoPE,  Ann.  Rept.  Chief  Engineers,  1874  (875),  p.  995  (of  separata,  p.  75);  Wheeler's 
Rept.  on  Surv.  W.  looth  Merid.,  iv,  1877,  p.  285,  plate  Ixvii,  fig.  3. — Hay,  Bibliog.  and  Cat.  Foss. 
Vert.  N.  A.,  1902,  p.  451. 

This  species  was  described  from  a  specimen  found  by  Professor  Cope  in  the  Loup  Fork 
Miocene  of  New  Mexico.    The  type  consisted  of  a  pygal  bone  (fig.  574).    This  is  now  in  the 

U.  S.  National  Museum  at  Washington.     Its  catalog  number 
is  2126.    Cope's  description  is  as  follows: 

Indicated  especially  by  a  caudal  bone  of  a  tortoise  of  larger 
size  than  the  one  regarded  as  typical  of  the  T.  undata.  It  is,  of 
course,  probable  that  some  of  the  fragments  above  described  with- 
out especial  reference  belong  to  it.  The  caudal  bone  differs  from 
that  of  T.  undata  in  being  nearly  plane,  and  thus  wanting  the  recur- 
vature or  superior  concavity  of  the  corresponding  bone  of  that 
species.  Its  form  is  also  quite  different.  Its  lateral  sutures  are 
nearly  parallel,  instead  of  divergent  anteriorly,  and  slightly  concave; 
if  a  little  expanded  proximally,  it  contracts  again  to  the  suture  for 
the  pygal  bone.  The  suture  is  a  short  squamosal  on  the  outside  of 

,.                  cr-        J    i;  ..•          ij       1  the  caudal.    The  thickness  of  the  bone  is  almost  uniform  to  near 

rlG.  S74- — J  estudo  klettiana.  1  ygal  ,              .       ,                   ,                 111                                •        , 

->'       .        ,                  .,^1  the  proxmial  suture;  there  an  abrupt  rabbet  commences  the  plane 

formmg  the  type.     Xj.  r./    .■•                  ,                            '^                                            '^ 

^           -"^  ot  the  thmner  pygal. 


TESTUDINID^.  437 

Measurements. 

Meter. 

Width,  proximal 0.105 

Width,  distal 110 

Length no 

Thickness 109 

The  free  margin  is  slightly  convex. 

To  this  description  it  may  be  added  that  the  thickness  of  most  parts  of  the  bone  is  20  mm. 
The  free  border  is  acute;   most  so  near  the  midline. 

There  is  no  satisfactory  evidence  that  the  bones  which  furnisht  Cope's  figs.  4  and  5,  of  the 
plate  cited  in  the  synonymy,  belonged  to  this  species. 

The  form  of  the  pygal,  the  lateral  borders  of  which  are  parallel,  appears  to  distinguish  this 
species  from  all  others  of  our  fossil  species  of  TrstuJo. 

Testudo  niobrarensis  Leidy. 

i'igs-  575-578- 

Tesiudo  {Stylemys)  niobrarensis,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.   1858,  p.  29;    Extinct  Mamm. 

Fauna  I3ak.  and  Neb.,  in  Jour.  Phila.  Acad.  Nat.  Sci.  Phila.  (2),  vii,  1869,  p.  26. 
Testudo  (Stylemys)  niobrarensis,  Hayden,  Proc.  Acad.  Nat.  Sci.  Phila.,  1858,  p.  158. 
Stylemys  niobrarensis.  Cope,  Ext.  Batrach.,  Reptilia,  Aves  N.  A.,  1869,  p.  124. — Leidy,  2d  (4th)  Ann. 
Rept.  U.  S.  Geol.  Surv.  Wyoming,  1871,  p.  366;  Contrib.  Extinct  Vert.  Fauna  West.  Terrs.,  1873, 
p.  225,  plate  iii,  figs.  4-6. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  450. 
Testudo  niobrarensis,  Leidy,  Contrib.  Extinct  Fauna  West.  Terrs.,  1873,  p.  340,  plate  xix,  figs.  6,  8. 

This  species  was  based  on  fragmentary  bones  which  were  collected  by  Dr.  F.  V.  Hayden, 
in  the  year  1857,  in  what  were  regarded  as  Pliocene  sands  along  the  Niobrara  River.    These 


Figs.  575-578. — Testudo  niobrarensis.     Plastron,  pygal,  and  suprapygal.     U.  S.  N.  M. 


575.  Upper  surface  of  plastron,    X§. 

576.  Lower  surface  of  plastron.    Xj. 


577.  Suprapygal  and  pygal.     Xj.    Seen  from  above. 

578.  Section  of  pygal  and  suprapygal.     Xi. 


deposits  are  now  regarded  as  belonging  to  the  Loup  Fork  Miocene.  No  exact  statement 
regarding  the  locality  is  given,  but  it  was  in  all  probability  within  the  state  of  Nebraska.  The 
specimens  are  in  the  U.  S.  National  Museum,  at  Washington. 

The  materials  described  and  figured  by  Leidy  consisted  of  the  anterior  portion  of  the 
plastron,  the  posterior  suprapygal  and  the  pygal,  the  hinder  median  portion  of  the  carapace, 
the  distal  part  of  one  humerus,  and  the  distal  part  of  one  femur.  These  did  not  all  belong  to 
one  individual.  The  figures  of  the  plastron,  the  pygal,  and  suprapygal,  being  parts  most 
characteristic,  are  here  reproduced.  It  seems  best,  considering  the  possibility  that  more  than 
a  single  species  is  here  included,  to  take  as  the  type  of  the  species  the  figured  epiplastral  lip. 
This  is  No.  956  of  the  U.  S.  National  Museum.  Leidy's  figure  of  the  pygal  and  suprapygal  is 
two-thirds  the  size  of  the  original  bones,  altho  he  states  in  the  explanation  of  the  plate  that  it  is 
the  size  of  nature. 


43^  FOSSII.    TURTLES    OK    NORTH    AMERICA. 

In  some  of  his  earlier  references  to  this  species  Leidy  was  in  doubt  regarding  its  distinctness 
from  Stylemys  nehrascensis,  but  in  his  latest  description  he  pointed  out  one  character  which 
definitely  separates  it  from  the  White  River  species.  This  is  found  in  the  lip,  which  projects 
well  beyond  the  general  contour  of  the  plastron  and  has  a  deep  excavation  beneath  its  backward 
extension  on  the  upper  surface  of  the  lobe. 

The  plastral  lip  (figs.  575,  576)  is  36  mm.  wide,  measured  from  where  one  gulo-humeral 
sulcus  crosses  the  free  border  to  the  crossing  of  the  other.  From  a  line  on  the  upper  side  join- 
ing these  points  the  rounded,  slightly  notcht  lip  extends  forward  13  mm.  and  backward  9  mm. 
Its  hinder  border  overhangs  the  excavation.  The  gulo-humeral  sulci  on  this  upper  surface  are 
18  mm.  long,  that  is,  about  one-third  of  the  width  of  the  base  of  the  lip.  The  present  thickness 
of  the  lip  is  18  mm.     It  appears  to  have  been  somewhat  convex  from  side  to  side  above. 

From  the  original  of  Leidy's  fig.  6,  plate  iii,  we  learn  that  the  fourth  vertebral  scute  was 
155  mm.  long  and  148  mm.  wide,  and  that  it  occupied  a  portion  of  the  eighth  neural. 

The  pygal  (fig.  577)  widens  from  the  free  to  the  superior  border.  Above,  it  is  somewhat 
excavated  for  the  reception  of  the  suprapygal.  As  shown  by  fig.  578,  which  represents  the 
perpendicular  section  thru  the  pygal  and  the  suprapygal,  the  pygal  was  slightly  flared  outward. 
The  free  border  is  obtuse.    The  greatest  thickness  is  13  mm. 

The  part  of  the  carapace  figured  by  Leidy  (No.  93,  U.  S.  N.  M.)  must  have  belonged  to  an 
individual  about  610  mm.  long.  The  part  included  the  sixth,  seventh,  and  eighth  neurals, 
parts  of  the  corresponding  costal  plates,  and  the  upper  end  of  the  bifurcated  suprapygal.  The 
fourth  vertebral  scute  had  a  length  of  155  mm.  The  upper  ends  of  the  costals  are  15  mm. 
thick.     The  limb  bones  figured  by  Leidy  offer  no  novel  characters. 

This  species  appears  to  be  distinguisht  from  both  7 .  vaga  and  the  younger  specimens  of 
T .  osborntana  by  the  more  prominent  plastral  lip  and  the  shortness  of  the  gulo-humeral  sulcus 
on  the  upper  side  of  each  epiplastron.  The  pygal  appears  to  differ  from  that  of  T.  osborntana 
in  being  obtuse  on  the  free  edge.  It  appears  likewise  to  belong  to  a  more  recent  formation  than 
either  of  the  species  just  named.  From  T.  farrt  of  the  Deep  River  formation  it  differs  in  the 
more  projecting  epiplastral  lip  and  more  elongated  entoplastron. 

Testudo  orthopygia  (Cope). 

Plate  19,  figs.  6,  7;    plates  72-75;  78-80,  fig.  i;   text-figs.  579-606. 

Xerobates  orthopygius.  Cope,  Bull.  U.  S.  Gaol,  and  Geog.  Surv.  Terrs.,  iv,  1878,  p.  393. 

Testudo  orthopygia.  Hay,  Amer.  Geologist,  xxiv,  1899,  p.  349;    Bibliog.  and  Cat.  Foss.  Vert.  N.  A., 

1902,  p.  451- 
Xerobates  cyclopygius,  CoPE,  Bull.  U.  S.  Geol.  and  Geog.  Surv.  Terrs.,  iv,  1878,  394. 
Testudo  cyclopygia.  Hay,  Amer.  Geologist,  xxiv,  1899,  p.  349;  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902, 

p.  45'- 
Caryoderma  snovtanum,  CoPE,  Amer.  Naturalist,  xx,  1886,  p.  1044;    Amer.  Naturalist,  XXIII,  1889, 

p.   662,   plate   xxxii,   figs.    1-17. 
Testudo  undata?,  Williston,  Science  (2),  vill,   1898,  p.   1 32. 
Testudo  snoviana,  Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  451. 

In  the  year  1877  a  party  consisting  of  Messrs.  C.  H.  Sternberg,  R.  S.  Hill,  and  W.  J.  Brous 
collected  from  the  Loup  Fork  beds  of  Decatur  County,  Kansas,  a  considerable  number  of 
specimens  of  turtles  belonging  to  the  genus  Testudo.  Out  of  these  materials  Professor  Cope 
described  2  species,  giving  them  the  names  referred  to  him  in  the  synonymy  above.  These 
specimens  are  now  in  the  American  Museum  of  Natural  History  and  have  been  studied  by  the 
present  writer,  with  the  result  that  they  are  all  assigned  to  one  species,  which  must  bear  the 
name  orthopygia.  According  to  Cope's  description,  there  existed  between  his  two  species  a 
great  difference,  one  having  the  hinder  border  of  the  carapace  broadly  rounded,  the  other 
having  it  nearly  straight  and  with  rounded  angles  behind  the  inguinal  notches.  This  striking 
difference,  however,  disappeared  when  it  was  discovered  that  Cope  had  mistaken  the  anterior 
border  of  the  carapace  of  the  type  of  his  orthopygia  for  the  posterior.  This  being  the  case,  it 
would  be  more  appropriate  to  call  the  species  cyclopygia,  but  the  other  name  having  preceded 
the  latter  in  the  description,  we  must,  according  to  rules  adopted,  retain  the  name  orthopygia. 

The  type  of  the  species  T.  orthopygia  bears  the  museum's  number  3929.  It  consists  of  the 
skull  and  lower  jaw;  the  plastron  quite  complete;   nearly  the  whole  of  the  anterior  free  border 


TESTUDINID^..  439 

of  the  carapace;  peripherals  7,  8,  10,  and  11  of  the  right  side;  peripheral  11  of^the  left  side; 
the  pygal;  fragments  of  the  costals  and  neurals;  the  right  humerus;  the  left  radius;  the  left 
fibula;  and  the  left  half  of  the  pelvis.  Cope  states  that  the  limbs  were  present,  but  no  other 
parts  of  these  now  remain  than  those  just  mentioned.  The  plastron  indicates  bv  its  flatness 
that  the  individual  was  a  female. 

The  skull  (figs.  579-582)  is  nearly  complete  and  has  been  described  by  Cope.  A  com- 
parison of  the  table  of  measurements  here  given  with  those  presented  by  that  author  shows  that 
some  of  the  latter  are  incorrect.     Cope's  figures,  when  difl^ering,  are  given  in  parentheses. 

Millimeters. 

Length  of  skull  from  snout  to  end  of  supraoccipital  spine.  ...  115 

Length  of  skull  from  snout  to  end  of  occipital  condyle 99 

Width  of  skull  at  quadrates 72  (80) 

Width  of  interorbital  space 28(19) 

Greatest  width  of  palatal  fossa 32  (36) 

Elevation  of  occiput  above  basisphenoid 33 

Length  of  mandible  from  articular  to  symphysis 75 

Depth  of  mandible  at  symphysis 18  (19) 

The  skull  is  neither  elongated  nor  broad.  Seen  from  above  (fig.  579),  the  outlines  expand 
from  the  squamosal  processes  forward  to  the  front  of  the  quadrates.     From  the  hinder  ends 


579- 


580. 


KiGS.  579  AND  580. — TestuJo  orthopygia.     Skull  of  type.     X  ^■ 
579.  Upper  surface.  580.  Palatal  surface. 

of  the  maxillae  the  outlines  converge  rapidly  to  the  snout.  The  interorbital  space  is  rather 
wide  and  flat.  The  antero-posterior  width  across  the  paroccipital  and  prootic  is  20  mm.,  while 
that  from  the  prootic  to  the  hinder  border  of  the  postfrontal  is  25  mm.  Both  squamosals  are 
missing.  On  the  right  side,  as  shown  in  fig.  581,  the  absence  of  the  squamosal  has  exposed  an 
opening  into  the  tympanic  cavity  of  the  quadrate.  On  the  left  side  a  considerable  portion  of 
the  hinder  region  of  the  quadrate  has  been  broken  away.  The  roof  of  the  tympanic  cavity 
does  not  rise  much  above  the  upper  surface  of  the  paroccipital,  and  no  prominent  ridge  ran 
backward  on  the  squamosal. 

The  jugal  arches  are  damaged,  but  they  appear  to  have  been  narrow;  there  is  evidence 
that  they  were  at  least  1 1  mm.  wide.  The  orbits  are  nearly  circular,  and  the  antero-posterior 
diameter  is  27  mm.  The  nasal  opening  has  a  transverse  width  of  21  mm.  There  is  a  median 
notch  at  the  symphysis  of  the  premaxillae.  The  cutting-border  of  the  maxilla  (fig.  581)  is 
nearly  straight,  but  the  hinder  end  is  missing.  The  palatal  fossa  (fig.  580)  is  wide  and  deeply 
excavated.    Cope  states  that  the  width  is  36  mm.    This  seems  to  be  too  great,  but  the  limits 


440 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


are  somewhat  indefinite.  There  is  no  longitudinal  ridge  along  the  premaxillary  symphysis; 
hence  the  species  is  not  a  Gopherus,  as  defined  by  Agassiz  under  the  name  Xerobates.  The 
outer  masticatory  ridge  is  somewhat  tootht;  the  inner  ridge  is  rugose,  especially  posteriorly. 
The  latter  nearly  meet  on  the  hinder  borders  of  the  premaxillae.  The  distance  across  the 
pterygoids,  where  narrowest,  is  1 8  mm.  There  are  distinct  ectopterygoid  processes.  The 
outward  border  of  each  pterygoid  is  continued  backward  and  outward  as  a  sharp  ridge  to  the 
hinder  part  of  the  base  of  the  quadrate.  From  the  fore  part  of  this  base  another  sharp  ridge 
runs  upward  and  inward  mostly  on  the  quadrate.  Between  the  two  ridges  is  found  a  rather 
deep  groove. 

The  lower  jaw  (fig.  582)  is  complete.  The  depth  varies  from  22  mm.  at  the  coronoid 
process  to  18  mm.  at  the  symphysis.  The  masticatory  surface  is  traverst  lengthwise  by  a  deep 
groove;  this  does  not  join  that  of  the  opposite  side  at  the  symphysis.  The  external  masti- 
catory ridge  is  sharp  and  furnisht  with  small  tooth-like  processes.  From  these  processes  sharp 
ridges  run  down  on  the  outside  of  the  jaw.  The  internal  masticatory  ridge  rises  higher  than 
the  external.  It  is  rough  and  dentated.  Anteriorly  these  inner  ridges  are  directed  forward  one 
on  each  side  of  the  symphysis  and  terminate  in  a  blunt  tooth  where  the  outer  ridges  meet  the 
symphysis. 


Figs.  581  and  582. — Testudo  orthopygia.     Skull  of  type,  with  lower  jaw.     X  §. 
581.  Side  view.  582.  Lower  jaw,  upper  view,    ar?,  articular;   (i^n,  dentaryj   5ur,  surangular. 

Several  of  the  dimensions  of  the  plastron  of  this  animal,  as  given  by  Cope,  differ  from  those 
obtained  by  the  present  writer.  In  the  following  table  Cope's  measurements  are  given  in 
parentheses,  when  differing  from  the  author's; 


Millimeters. 

Length  of  plastron  in  midline 515  (615) 

Width  of  plastron  at  axilla 330  (360) 

Width  at  inguinal  border 290  (310) 

Distance  between  posterior  apices 100 


Millimeters. 

Width  of  base  of  anterior  lip 132  (125) 

Width  at  end  of  anterior  lip 70 

Length  of  anterior  lip  above 105  (100) 


Some  of  these  discrepancies  may  be  due  to  misprints,  some  perhaps  to  different  methods 
of  taking  measurements;    but  others  appear  to  be  obvious  errors  of  determination. 

The  plastron  (plate  78,  fig.  i;  text-fig.  583)  is  somewhat  upturned  at  the  front;  also 
moderately  concave  in  the  middle.  Its  length,  given  as  515  mm.,  is  on  a  straight  line  from  the 
tip  of  the  anterior  lip  to  the  bottom  of  the  posterior  notch.  The  apices  of  the  posterior  lobe 
extend  about  24  mm.  further  backward.  The  width  of  the  plastron  across  the  middle  was 
close  to  450  mm.  The  greater  portion  of  the  free  borders  of  the  plastron  is  much  thickened. 
The  figures  indicate  the  form  of  the  anterior  lip.  The  width,  132  mm.,  is  that  taken  between 
the  points  where  the  sulci  forming  the  outer  boundaries  of  the  gular  scutes  cross  the  free 
border.  Superiorly  the  lip  runs  backward  some  distance  beyond  this.  Fig.  584  is  a  section 
at  what  is  here  termed  the  base;  and  fig.  585,  a  section  25  mm.  behind  the  end  of  the  lip. 
Fig.  586  is  a  longitudinal  section  of  the  lip  in  the  midline.  It  shows  to  what  extent  the  lip 
is  excavated  posteriorly. 

The  borders  of  the  anterior  lobe  from  the  front  to  the  axillae  are  acute.  From  the  border 
the  bone  thickens  for  nearly  50  mm.,  then  thins  toward  the  median  portion  of  the  plastron. 


TESTUDINID^. 


441 


At  the  junction  between  the  epiplastron  and  the  hyoplastron  the  greatest  thickness  is  30  mm. 
The  ascending  portion  of  the  hyoplastron  at  the  axilla  has  a  considerable  groove  behind  its 
free  border  and  on  the  inner  surface.  Most  of  the  hinder  border  of  the  entoplastron  is  at  present 
missing,  but  it  was  evidently  broad  and  rounded  behind  and  pointed  in  front.  The  length  in 
the  midline  was  close  to  no  mm.  The  greatest  width  is  160  mm.  The  extent  of  the  hyo- 
plastron in  the  midline  is  close  to  115  mm.  The  hypoplastra  occupy  130  mm.  of  the  midline; 
the  xiphiplastra,  97  mm. 

584.  588. 


KiGS.  585-590. — Testudo  orthopygia. 

83.  Plan  of  plastron,  taken  mostly  from  type.    Slightly  less  than  one-fifth  the  original. 

84.  Section  across  the  base  of  the  epiplastral  lip.    Xi- 

85.  Section  across  epiplastral  lip,  i$  mm.  behind  tip.    Xi- 

86.  Longitudinal  section  of  epiplastral  lip.    Xj. 

87.  Section  of  border  of  left  hypoplastron,  just  behind  inguinal  notch. 

88.  Pygal  and  left  eleventh  peripheral  of  type.    Xj. 

89.  Section  of  eleventh  peripheral  near  union  with  tenth.    Xj. 

90.  Pelvis  of  type,    fl,  lower  surface;   h,  left  side.    Xi-     i^j  ilium;   isch^  ischium;  pub,  pubis. 

The  hinder  lobe  of  the  plastron  (fig.  583)  is  short,  and  is  provided  with  a  notch  behind, 
which  has  a  width  of  100  mm.  and  a  depth  of  24  mm.  The  lobe  is  flat  below,  concave  above. 
At  the  inguinal  notch  (fig.  587)  there  is  a  wall  67  mm.  high,  with  a  perpendicular  outer  face, 
a  rounded  summit  16  mm.  thick,  and  a  steeply  sloping  inner  face.  Backward,  the  height  of 
the  wall  rapidly  diminishes,  and  the  outer  face  soon  changes  to  a  slope  less  and  less  steep. 
At  the  apices  of  the  lobe  the  height  of  the  wall,  above  the  lower  surface  of  the  bone,  is  only  30 
mm.  Its  width  here  is  45  mm.  The  middle  portions  of  the  lobe  are  about  12  mm.  thick.  The 
free  borders  of  the  lobe  in  the  notch  are  acute. 


442 


FOSSIL    TURTLES    OP'    NORTH    AMERICA. 


The  sulci  of  the  plastron  (fig.  583)  are  deeply  imprest.  The  gulars  extend  backward  on 
the  entoplastron.  The  humerals  occupy  85  mm.  of  the  median  line;  the  pectorals  only  about 
18  mm.;    the  abdominals,  200  mm.;   the  femorals,  68  mm.;    the  anals,  68  mm. 

As  already  stated,  Professor  Cope  described  the  anterior  portion  of  the  carapace  as  the 
posterior.  The  evidence  that  the  portion  here  regarded  as  the  anterior  is  such  is  found  in  the 
fact  that  the  buttress  which  ascends  from  the  plastron  is  on  the  third  peripheral  from  the 
median  element;  whereas,  the  buttress  at  the  inguinal  notch  ascends  on  the  fifth  peripheral 
from  the  hinder  median  element,  the  pygal.  That  Cope  had  this  anterior  rim  in  view  is  shown 
by  the  fact  that  it  corresponds  exactly  with  his  description,  while  the  portion  of  the  posterior 
rim  present  does  not  so  correspond.  All  that  Cope  had  to  say  about  any  part  of  the  anterior 
peripherals  was  a  statement  of  the  dimensions  of  one  of  them,  and  these  figures  apply  quite 
well  to  the  eleventh  peripheral. 

The  carapace  was  470  mm.  wide,  probably  rather  high  and  vaulted,  abruptly  curved  in 
front  of  the  axillary  notches,  somewhat  concave  in  front,  and  broadly  rounded  behind. 

The  abrupt  curves  in  the  front  of  the  shell  occur  on  the  second  peripherals.  The  nuchal 
and  the  anterior  peripherals  come  to  an  acute  edge.  Backward  from  this  edge  the  bones 
thicken  rapidly,  become  concave  above,  especially  the  second  peripherals,  and  quite  convex 
below.  The  nuchal  bone  occupied  105  mm.  of  the  free  border  and  its  greatest  thickness  is 
30  mm.  At  the  midline,  the  border  of  the  carapace  apparently  lackt  55  mm.  of  extending  as 
far  forward  as  the  tip  of  the  plastron. 

592. 


Figs.  591-593- — TestuJo  orthopygia.     Epiplastral  lip.     X\-     No.  1325  A.  M.  N.  H. 
591.  Upper  surface.  592.  Section  at  ends  of  gulo-humeral  sulci.  593.  Longitudinal  section. 

The  hinder  peripherals  flare  upward  somewhat  as  the  free  border  is  approacht.  The 
eleventh  (fig.  588)  occupies  80  mm.  of  the  free  border,  is  34  mm.  thick  and  107  mm.  high. 
The  pygal  (figs.  588,  589)  is  75  mm.  wide  at  the  free  border  and  about  75  mm.  high. 

Only  unimportant  fragments  of  the  neurals  and  costals  of  the  type  specimen  remain. 
There  was  the  same  alternation  of  larger  and  smaller  neurals  that  we  see  in  the  living  species 
of  the  genus.  Likewise,  the  proximal  ends  of  the  costals  were  alternately  narrow  and  wide. 
Two  costals,  which  are  regarded  as  the  third  and  fourth  of  the  left  side,  are  represented  by 
their  proximal  ends.  The  third  is  75  mm.  wide  where  it  has  joined  the  neurals,  while  the 
fourth  is  only  44  mm.  wide.    The  bone  is  8  mm.  thick. 

There  is  present  with  the  type  a  humerus  which  lacks  the  distal  end.  There  is  no  femur 
present,  altho  Cope  mentions  one.  He  states  that  its  length,  estimating  for  the  absent  condyles, 
is  170  mm.  and  the  width  of  the  head  plus  the  great  trochanter  90  mm.  A  perfect  femur  of  a 
still  larger  specimen,  next  to  be  described,  has  a  length  of  only  150  mm.  The  humerus  referred 
to,  allowing  for  the  missing  distal  end,  had  a  length  of  about  170  mm.  and  a  thickness  thru 
the  head  and  the  ulnar  tuberosity,  of  85  mm.  It  seems  evident,  therefore,  that  Professor  Cope 
inadvertently  spoke  of  the  humerus  as  the  femur.  As  the  complete  humerus  of  another 
specimen  will  be  described,  that  of  the  type  will  be  passed  by. 


TESTUDINIO^. 


443 


The  pelvis  (figs.  590  a,  h)  is  represented  by  the  greater  portion  of  the  left  side.  The  lateral 
process  of  the  pubis  is  rather  short,  flat,  and  broad  and  rounded  at  the  end.  The  tuber  ischii 
is  rather  slender  and  pointed. 

No.  1325  of  the  American  Museum  is  likewise  a  part  of  the  Cope  collection.  It  was  a 
larger  animal  than  the  type  just  described.  The  length  of  the  plastron  is  615  mm.  and  its 
width  to  the  outer  borders  of  the  bridge  peripherals  could  not  have  been  less  than  555  mm. 
The  width  of  the  carapace  at  the  inguinal  notches  was  600  mm.  Almost  the  whole  of  the 
plastron  is  present;  also  considerable  parts  of  the  costals  and  neurals  in  a  fragmentary  state; 
and  the  greater  part  of  the  rim  of  the  carapace,  of  the  shoulder-girdle,  of  the  pelvis,  and  of  the 
limbs.  The  plastron  differs  from  that  of  the  type  principally  in  the  size  and  form  of  the 
anterior  lip.    This  (fig.  591)  is  relatively  broader,  with  its  sides  less  converging,  leSs  truncate 

in  front,  and  less  cari- 
nated  above.  Since,  how- 
ever, the  two  individuals 
are  so  closely  alike  in  all 
other  respects  and  there 
seems  to  be  a  good  deal 
of  variation  in  the  form 
of  the  lip  among  the  var- 
ious specimens,  there  is 
apparently  no  sufficient 
reason  for  regarding  No. 
1325  as  belonging  to  a 
diflFerent  species.  The 
width  of  the  lipat  the  base 
is  184  mm.  Where  the 
curve  of  the  sides  into  the 
anterior  border  is  made 
the  width  is  150  mm. 
Instead  of  being  slightly 
notcht  in  front,  the  ante- 
rior border  is  broadly 
rounded.  From  side  to 
side  the  upper  surface  is 
evenly  convex.  Figs.  592, 
593  represent  sections  of 
the  lip. 

The  entoplastron  is  163 
mm.  long  and  200  mm. 
wide.  The  humero-pec- 
toral  sulcus  passes  just 
behind  its  hinder  border. 
The  plastron  is  rather 
deeply  concave  in  front  of  the  hinder  lobe,  a  condition  which  indicates  that  the  individual 
was  a  male.     Fig.  2  of  plate  78  gives  a  view  of  the  rear  of  the  shell  seen  from  below. 

Of  the  anterior  portion  of  the  carapace  only  peripherals  I,  2,  and  3  are  present.  They 
differ  in  no  important  respect  from  the  corresponding  elements  of  the  type.  Almost  the  whole 
of  the  posterior  rim  is  present,  the  pygal  and  most  of  the  peripherals  being  complete.  At  the 
midline  the  hinder  edge  of  the  carapace  falls  about  120  mm.  behind  the  plastron.  The  upper 
portion  of  the  peripherals  is  nearly  perpendicular,  but  the  lower  portion  is  considerably  flared 
outward.  The  eighth  peripheral  has  a  height  of  160  mm.;  the  eleventh,  of  120  mm.  The 
second  suprapygal  is  present,  of  rhombic  form,  and  about  no  mm.  from  side  to  side.  Its 
lower  half  is  placed  in  a  notch  in  the  pygal.  The  sulcus  behind  the  fifth  vertebral  scute  crosses 
it  horizontally  in  the  middle.  Costals  and  neurals  too  fragmentary  to  justify  description. 
The  left  scapula  is  present  in  No.  1325.  The  length  of  the  bone  from  the  superior  extremity 
to  the  middle  of  the  glenoid  fossa  is  180  mm.;    from  the  latter  point  to  the  extremity  of  the 


Kics.  594  AND  595. — Testudo  orthopygia.     Left  humerus.     Xj- 
No.  1^25  A.  M.'N.  H. 


594.  Radial  border. 


595.  Dorsal  surface. 


444  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

procoracoid  process  is  125  mm.    The  two  branches  of  the  bone  make  an  angle  of  about  120° 
with  each  other.    The  bone  is  a  stout  one,  the  width  across  it  at  the  glenoid  fossa  being  50  mm. 

The  left  humerus  (figs.  594,  595)  is  complete,  with  the  exception  of  a  missing  part  of  the 
ulnar  process.  It  is  a  stout  bone,  but  not  so  much  curved  as  in  some  species  of  the  genus,  even 
less  so  than  in  Gopherus  polyphemus.  The  total  length  is  200  mm.;  the  diameter  thru  the 
head  and  ulnar  process  is  100  mm.;  thru  the  external  and  internal  condyles,  76  mm.;  and  thru 
the  narrowest  portion  of  the  shaft,  35  mm.  The  planes  of  the  ulnar  and  radial  tuberosities 
make  a  small  angle  between  them,  about  the  same  as  in  G.  polyphemus.  The  trochlear  surface 
is  well  defined.  When  the  bone  is  in  its  natural  position,  this  surface  is  directed  strongly  down- 
ward.   It  is  traverst  from  the  dorsal  to  the  ventral  surface  by  a  broad  and  rather  deep  groove. 

The  left  radius  and  ulna  are  represented  in  fig.  596,  but  more  or  less  hidden  by  portions 
of  the  dermal  armor.  They  are  stout  bones,  the  ulna  having  a  length  of  no  mm.,  a  breadth 
across  the  middle  of  the  shaft  of  29  mm.,  across  the  distal  end  of  43  mm.  The  radius  has 
a  total  length  of  112  mm.  The  head  is  expanded.  The  slender  portion  of  the  shaft  has  a 
diameter  of  16  mm. 

The  bones  of  the  digits  are  all  present,  except  the  ungual  phalanx  of  the  first.  Some  of  the 
bones  are  slightly  disturbed  and  their  positions  are  somewhat  obscured  by  the  dermal  bones; 
but  some  notes  are  obtained  regarding  them.  The  radiale  is  a  small  bone  which  does  not  ex- 
clude the  first  carpal  from  extensive  connection  with  the  radius.  This  radiale  has  a  rhombic 
superior  surface,  articulates  by  its  proximal  surface  with  the  intermedium,  and  by  its  radial 
surface  with  the  radius.  The  intermedium  is  elongated  in  the  direction  of  the  axis  of  the  limb, 
articulates  by  its  proximal  end  with  the  ulna  and  by  its  radial  surface  with  the  upper  portion 
of  the  articulatory  surface  of  the  radius.  The  length  of  the  intermedium  is  24  mm.  The  ulnare 
is  not  sufficiently  enlarged  to  exclude  the  fifth  carpal  from  contact  with  the  ulna. 

Carpale  i  is  rather  larger  than  the  radiale,  and  articulates  extensively  with  the  distal  end 
of  the  radius.  The  ungual  phalanges  vary  in  length  from  34  mm.  in  the  first  to  38  mm.  in  the 
last.    They  are  flat  or  slightly  convex  both  above  and  below,  and  their  distal  ends  are  blunt. 

In  the  small  size  of  the  radiale  and  ulnare  the  bones  of  this  carpus  resemble  most  those 
oi  Gopherus  polyphemus,  but  in  the  latter  carpale  2  also  joins  the  radius. 

Of  the  pelvis  there  are  present  portions  of  both  sides.  The  ilium  has  a  total  length  of 
155  mm.  Its  greatest  diameter,  at  the  upper  border  of  the  acetabulum,  is  71  mm.  The  lateral 
process  of  each  pubic  bone  is  broad  and  flat,  and  the  distal  end  is  rounded. 

Both  femora  have  been  preserved.  They  too  are  stout  bones,  little  bent,  and  having  the 
distal  articular  surface  directed  strongly  downward,  when  the  bone  is  in  its  natural  position. 
That  of  the  right  side  is  shown  in  figs.  597,  598.  The  total  length,  measured  parallel  with  the 
axis  of  the  bone,  is  150  mm.  Thru  the  head  and  the  trochanter  the  distance  is  "/y  mm.;  thru 
the  tuberosities,  63  mm.  The  shortest  diameter  of  the  shaft  is  24  mm.  A  ridge  separates 
the  fibular  cond3'le  from  that  for  the  tibia.  The  latter  has  a  broad  groove  running  dorso- 
ventrally. 

The  tibia  (fig.  598)  is  also  a  relatively  short  and  thick  bone,  the  length  being  99  mm.,  the 
distance  thru  the  tuberosities  46  mm. 

Most  of  the  bones  of  the  left  hind  foot  (fig.  599)  are  so  completely  hidden  by  the  dermal 
armor  that,  with  the  exception  of  the  ungual  phalanges  and  calcaneum,  they  can  not  be 
studied.  The  calcaneum  resembles  that  of  other  species  of  Testudo.  The  ungual  phalanges, 
4  in  number,  resemble  those  of  the  forefoot. 

Fig.  600  represents  the  terminal  six  vertebrx  of  the  tail.  The  lateral  processes  are  some- 
what elongated,  so  that  the  end  of  the  tail  is  paddle-shaped,  instead  of  pointed.  The  last  three 
vertebrae  are  consolidated  into  one  mass.  Two  or  three  vertebrae  above  those  shown  in  fig.  601 
have  their  lateral  processes  standing  at  right  angles  with  the  centra. 

Professor  Cope  made  the  observation  that  this  species  possest  numerous  osseous  bosses  on 
the  limbs,  doubtless  ossifications  of  large  marginal  and  other  dermal  scutes.  These  are  said  to 
have  a  low  apex,  central  or  concentric.  Further  description  was  not  furnisht.  More  complete 
preparation  of  his  specimens,  especially  No.  1325,  shows  that  these  bosses  were  found  on  the 
fore  limbs,  the  hind  limbs,  and  on  the  tail  and  the  region  surrounding  the  latter.  Fig.  595 
shows  a  number  of  these  osseous  scutes  on  the  upper  surface  of  the  distal  end  of  the  humerus. 
They  are  rather  small  and  closely  joined.    No  doubt,  they  lay  embedded  in  the  skin  that  cov- 


TESTUDINID^. 


445 


ered  this  bone  and  each  was  covered  with  a  horny  scute.  Fig.  596  represents  the  armor  of 
bony  nodules  which  covered  the  outside,  or  dorsal  surface,  of  the  lower  arm  and  foot.  Here  the 
nodules  are  large.  The  one  lying  across  the  ulna  is  really  formed  of  two,  suturally  joined.  In 
all  of  these,  the  outer  surface  is  flat  or  slightly  convex;  while  the  deeper  surface  is  more  strongly 
convex,  sometimes  forming  a  low  apex.  On  the  forearm  and  foot  the  lower  end  of  each  scute 
overlaps  the  next  one  below.  The  same  specimen  shows  that  the  bottom  of  the  foot  was  shod 
with  these  bony  scutes.  Close  to  the  toes  they  are  small,  but  beneath  the  carpal  bones  and  on 
the  ulna  are  some  very  large  ones,  flat  externally,  convex  on  the  inner  surface. 

596.  597.  598a. 


599.  600.  598^. 

Figs.  596-600. — TestuJo  orthopygia.     Limb   bone.s   and   tail.     Xi-     No.  1325  A.  M.  N.  H. 

596.  Ulna,  radius  and  front,  with  dermal  ossicles.  597.  Femur,  tibial  border. 

598.  Right  femur  {a)  and  tibia  (d),  dorsal  view.  599.  Sole  of  hind  foot.  600.  Tail,  lower  surface. 

Fig.  602  represents  the  left  femur,  seen  from  the  ventral  side.  At  the  proximal  end  is  seen 
a  patch  of  nodules  which  probably  occupied  the  skin  just  outside  of  the  lateral  border  of  the 
hinder  lobe  of  the  plastron.  No  specimen  shows  these  nodules  on  the  lower  portion  of  the 
femur,  but  we  can  hardly  doubt  that  they  covered  also  these  portions  of  the  limb.  Fig.  599 
shows  the  bottom  of  the  hind  foot.  This  is  seen  to  have  been  heavily  armored  with  these 
bony  plates.  Those  near  the  ungual  phalanges  are  smaller;  those  at  the  heel,  quite  large  and 
thin.    Others  quite  small  appear  to  have  been  found  somewhat  higher  up  on  the  foot. 


446 


FOSSIL    TURTLES    OK    NORTH    AMERICA. 


In  fig.  603  we  have  a  view  of  the  dermal  armor  that  covers  the  end  of  the  tail.  This  con- 
sists principally  of  about  12  polygonal  bones  which  are  suturally  joined.  Around  these  are 
arranged  smaller  bony  scutes  which  are  less  closely  joined,  and  which  evidently  permitted  a 
bending  of  the  skin.  The  lower  border  of  the  fragment  here  figured  rested  on  the  upper  sur- 
face of  the  hinder  border  of  the  plastron,  doubtless  just  in  the  position  occupied  during  life. 
On  another  fragment  (fig.  604),  belonging  higher  up  on  the  tail,  there  are  other  ossicles  and 
a  conical  bony  spur.  This  spur  is  38  mm.  long,  18  mm.  in  diameter  at  the  base,  and  some- 
what curved.  The  coat  of  mail  found  on  and  around  the  tail  resembles  that  found  in  T. 
osborniana.  Its  purpose  was  evidently  to  close  up  effectually  the  space  between  the  feet  when 
these  were  withdrawn  into  the  shell. 

There  can  scarcely  be  a  doubt  that  the  dermal  bones  and  the  ungual  phalanx  described 
as  cited  in  the  synonymy,  by  Professor  Cope,  under  the  name  Caryoderma  snovianum  and 
thought  by  him  to  belong  to  a  glyptodont,  belong  in  reality  to  this  species.  Entirely  similar 
bones  are  among  the  specimens  of  T .  orthopygia  collected  for  this  author  and  described  by  him 
in  1878.  Dr.  S.  W.  Williston  first  made  the  observation  that  these  supposed  Edentate  bones 
were  those  of  a  turtle  and  referred  them  with  doubt  to  Testudo  undata.  The  types  of  Caryo- 
derma snovianum  are  in  the  University  of  Kansas  and  were  found  in  the  Loup  Fork  deposits 
of  northern  Kansas. 


601.  602.  60  j. 

Figs.  601-603. — Testudo  orthopygia.     Femur  and  tail.     X  ^-     No.   1325  A.  M.  N.  H. 

601.  Two  caudal  vertebrs,  lower  side.  602.  Proximal  end  of  femur,  ventral  surface,  with  dermal  bones. 

603.  Tail,  upper  surface,  covered  with  an  armor  of  dermal  ossicles. 

In  Cope's  description  of  his  Xerobates  cyclopygia  three  specimens  appear  to  have  been 
studied.  In  his  table  of  measurements  these  are  designated  as  "No.  I,"  "No.  2,"  and  "No.  3." 
His  "No.  i"  is  identified  by  the  present  writer  as  No.  1322  (plate  19,  fig.  6)  of  the  American 
Museum  of  Natural  History,  since  there  is  no  other  in  the  Cope  collection  that  comes  so  near 
answering  the  requirements.  The  length  of  the  hinder  lobe  is  said  to  be  140  mm.,  and  the 
width  240  mm.;  but  the  latter  is  really  270  mm.  With  this  specimen  are  many  fragments  of 
the  carapace.  The  anterior  lobe  of  the  plastron  is  missing.  A  portion  of  the  entoplastron  is 
present,  but  not  enough  to  determine  its  dimensions.  The  bottom  of  the  plastron  is  quite  flat, 
there  being  only  the  slightest  concavity  in  front  of  the  hinder  lobe.  The  form  of  the  hinder  lobe 
is  that  of  the  type  of  T .  orthopygia.  The  notch  in  the  hinder  border  has  a  width  of  76  mm. 
The  hyoplastra  occupied  112  mm.  of  the  midline;  the  hypoplastra,  122  mm.;  the  xiphiplastra, 
86  mm.  The  notch  has  a  depth  of  32  mm.  The  sutures  separating  the  hyoplastra  from  the 
xiphiplastra  are  extremely  coarse.  The  sulcus  which  runs  lengthwise  thru  the  middle  of  the 
plastron  is  very  wide  and  deep.  The  humero-pectoral  and  the  pectoro-abdominal  sulci  are  like- 
wise deep  but  narrow.  The  pectoral  scutes  are  extremely  narrow,  not  more  than  4  mm.  wide 
at  the  midline  but  widening  right  and  left.  The  abdominal  scutes  meet  along  the  midline 
190  mm.;  the  femoral  scutes,  57  mm.  The  femoro-anal  sulci  are  angulated  about  the  middle 
of  their  length.  The  areas  occupied  by  the  abdominal  scutes  are  broadly  grooved.  These 
grooves  indicate  the  stages  of  growth  of  the  scutes. 


TESTUDINID^. 


447 


Considerable  portions  of  the  carapace  of  this  specimen  are  preserved;  but  they  are  in  a 
fragmentary  condition.    The  costals  are  crost  by  conspicuous  ridges  and  grooves. 

Cope's  "No.  2,"  No.  1323  of  the  American  Museum,  presents  an  imperfect  carapace 
(plate  19,  fig.  7),  most  of  the  lateral  and  all  of  the  hinder  border  being  gone.  Cope  states  that 
the  axial  length  was  330  mm.;  but  it  is  certain  that  it  was  in  life  considerably  longer.  Cope 
describes  the  carapace  as  being  flattened,  but  this  appearance  is  undoubtedly  due  to  the  bad 
state  of  the  specimen.  The  front  outline  is  truncate,  with  the  nuchal  and  peripheral  bones  flared 
considerably  upward.  The  sutures  between  the  various  neurals  and  costals  are  not  well  shown. 
The  nuchal  scute  is  said  by  Cope  to  be  4  mm.  long,  but  this  appears  to  be  a  misprint  for  40  mm. 
Its  width  anteriorly  is  17  mm.;  posteriorly,  24  mm.  The  second  and  third  marginal  scutes  are 
67  mm.  wide  fore  and  aft.  The  first  vertebral  scute  is  1 10  mm.  wide  in  front  and  Jj  mm.  wide 
behind.  The  second  and  the  third  are  1 10  mm.  wide  across  the  middle,  and  this  width  is  about 
that  of  the  costal  scutes.  On  the  hinder  portion  of  the  first  vertebral  scute  area  is  a  conspicuous 
boss,  from  which  a  ridge  continues  forward  some  distance.     On  each  of  the  other  vertebral 


Figs.  604-606. — Testudo  nrthopygia.    Carapace  and  dermal  ossicles.    X  \- 

604.  Patch  of  dermal  armor  near  the  tail,  showing  a  bony  spur. 
605.  Plan  of  carapace,  constructed  from  various  specimens  in  A.  M.  N.  H.  606.  Ilium. 

areas  there  is  a  depression,  horseshoe-shaped,  with  the  opening  forward.  The  costal  bones  are 
grooved  and  ridged  parallel  with  the  borders  of  the  carapace. 

Cope's  "No.  3"  is  evidently  the  specimen  now  bearing  the  American  Museum's  number 
1324,  and  furnishes  the  hinder  half  of  the  carapace.  It  is  a  smaller  specimen  than  the  one 
described  above,  the  width  of  the  carapace  at  the  inguinal  notches  being  only  250  mm.  The 
hinder  border  is  rounded,  most  of  the  peripherals  are  somewhat  flared  upward  at  the  border, 
and  the  free  edges  are  acute.  The  fifth  vertebral  scute  is  33  mm.  wide  in  front,  100  mm.  behind 
and  62  mm.  long  in  the  midline.  All  of  the  costal  scute  areas  and  that  of  the  fifth  vertebral 
are  sculptured  with  grooves  and  ridges  which  run  parallel  with  the  border  of  the  carapace. 

After  a  study  of  all  the  materials  at  hand  the  writer  has  concluded  that  the  specimens 
called  cyclopygia  are  merely  the  young  and  half-grown  individuals  of  T.  orthopygia.  The 
grooving  of  the  carapace  may  be  observed  on  some  of  the  costals  of  specimens  that  must  be 
referred  to  orthopygia.  The  width  of  the  pectoral  scutes  varies  in  diflFerent  examples  and  prob- 
ably becomes  relatively  greater  in  the  older  individuals.  The  same  remark  may  be  made 
regarding  the  notch  in  the  rear  of  the  plastron.  The  anterior  lip  of  the  plastron  is  likewise 
variable, but  within  what  limits  it  is  hard  to  say.    The  usual  form  in  the  larger  individuals, some 


448 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


of  which  would  belong  to  cyclopygia,  is  that  of  the  type  of  T .  orthopygia.  In  one  specimen  of 
" cyclopygia, "  a  young  individual,  there  is  a  broad  longitudinal  groove  running  along  the  under 
side  of  the  lip,  and  another  on  the  upper  side.  This  specimen  and  others  of  similar  size  appear 
to  indicate  that  usually  during  growth  the  upper  groove  disappeared  and  this  surface  of  the  lip 
became  roof-shaped.  The  lip  of  No.  1325,  which  has  been  described  and  figured,  deviates 
most  from  the  typical  form  and  under  other  circumstances  might  possibly  be  regarded  as 
belonging  to  a  distinct  species. 

Fig.  605  is  a  diagram  of  the  carapace  made  up  from  the  various  specimens  in  the  Cope 
collection,  of  fossil  reptiles,  now  in  the  American  Museum  of  Natural  History. 

Plate  79,  figs.  I,  2  and  plate  80,  fig.  i,  present  views  of  this  species  seen  from  above,  below, 
and  from  the  right  side.  The  plastral  view  is  taken  almost  wholly  from  No.  2415,  A.  M.  N.  H., 
except  the  tip  of  the  anterior  lip  and  the  border  of  the  carapace  in  front  of  the  axillary  notch. 
These  parts  are  furnisht  by  No.  3931,  an  individual  of  the  same  size.  The  other  figures  have 
been  taken  mostly  from  No.  2415,  but  those  parts  in  front  of  an  irregular  line  extending  from 
the  front  of  the  third  neural  forward  and  outward  to  the  free  border  a  little  in  front  of  the 
axillary  notch  are  taken  from  Nos.  3931  and  2320.  The  tip  of  the  plastral  lip  is  completed  from 
No.  3931.    These  figures  reveal  the  great  height  of  the  peripheral  bones. 


607. 


608. 


Figs.  607  and  608. — Testudo  sp.  indet.     Pelvis  and  femur.     Xi-     No.  2416  A.  M.  N.  H. 
607.  Pelvis  showing  slender  lateral  pubic  process.  608.  Right  femur. 

Judging  from  the  numbers  of  this  species  in  the  Cope  collection,  it  must  have  been  very 
abundant.  Another  and  quite  perfect  specimen  is  in  the  museum  of  the  University  of  Kansas. 
Fig.  606  represents  an  ilium  of  No.  2426  of  the  American  Museum  of  Natural  History.  It  is 
that  of  the  right  side. 

Plates  81  and  82  are  reproduced  from  photographs  of  a  large  specimen  of  this  species 
which  belongs  to  the  American  Museum  of  Natural  History.  It  has  the  catalog  number  6108. 
This,  with  several  other  fine  specimens,  was  collected  in  the  year  1905,  by  Mr.  Charles  H. 
Sternberg,  in  the  typical  locality,  Decatur  County,  Kansas.  The  specimen  figured  has  the 
shell  complete,  with  the  exception  of  the  third,  fifth  and  sixth  costal  plates.  The  length  from 
the  anterior  end  of  the  plastron  to  the  hinder  border  of  the  carapace  is  710  mm.  The  plastron 
projects  beyond  the  anterior  border  of  the  carapace  80  mm.  The  width  of  the  carapace  is  520 
mm.    The  height  is  about  330  mm. 

The  plastron  is  622  mm.  long.  The  epiplastral  lip  is  nearly  flat  below,  roof-shaped  above. 
The  thickening  on  the  upper  surface  continues  backward  113  mm.     Here  the  thickness  is 


TESTUDINID^. 


449 


about  75  mm.  The  limbs  and  the  region  about  the  tail  present  the  armor  that  has  been  already 
described.  Another  shell  collected  by  Mr.  Sternberg  and  now  in  the  American  Museum  has 
a  total  length  of  800  mm. 

Among  the  materials  collected  by  Mr.  C.  H.  Sternberg  and  his  party,  in  1877,  in  the  Loup 
Fork  beds  of  Decatur  County,  Kansas,  are  some  portions  of  a  large  tortoise  which  appears  to 
be  specifically  different  from  T.  orthopygia.  The  portions  represented  by  determinable  bones 
are  the  greater  portion  of  the  shoulder-girdle,  the  right  half  of  the  pelvis,  and  the  femur.  The 
number  of  the  specimen  is  2416  of  the  American  Museum  of  Natural  History. 

The  length  of  the  coracoid,  from  the  suture  in  the  glenoid  fossa  to  the  inner  hinder  angle, 
is  135  mm.,  the  breadth  of  the  inner  border,  no  mm.,  and  the  breadth  across  the  neck  of  the 
bone  37  mm.  The  procoracoid  process  is  a  stout  bone,  without  distinctive  characters.  Only 
a  portion  of  the  scapula  remains. 

The  width  of  the  pelvis  (fig.  607),  from  the  pubic  border  of  one  acetabulum  to  that  of  the 
other,  was  226  mm.;  the  length  along  the  midline,  from  the  hinder  border  of  the  ischia  to  the 
notch  in  the  pubes,  135  mm.  The  least  width  of  the  ischium  mesiad  of  the  ischial  tuberosity 
is  43  mm.;  laterad  of  the  tuberosity,  28  mm.  The  least  width  of  the  pubis  mesiad  of  the 
lateral  process  is  32  mm.;  posterior  to  the  lateral  process,  38  mm.  The  symphysis  of  the 
ischia  is  very  thick,  22  mm.;  that  of  the  symphysis  of  the  pubes,  only  10  mm.  The  chief 
feature  which  distinguishes  the  pelvis  from  that  of  T.  orthopygia  is  found  in  the  lateral  process 
of  the  pubis.  In  T.  orthopygia  this  is  relatively  short,  but  broad  and  comprest,  with  the  upper 
surface  convex,  the  lower  concave,  the  distal  end  broadly  rounded,  and  the  horizontal  diameter 
nearly  twice  the  perpendicular.  In  the  pelvis  here  described  the  process  is  nearly  twice  as 
long  as  in  T.  orthopygia,  tapering,  convex  above,  with  a  prominent  ridge  below,  and  the 
horizontal  diameter  less  than  the  perpendicular. 

The  right  femur  (fig.  608)  is  nearly  complete,  the  head  only  being  somewhat  damaged.  It 
is  a  somewhat  slenderer  element  than  the  corresponding  bone  of  T.  orthopygia.  The  table  pre- 
sents the  measurements  of  this  bone 
compared  with  those  of  the  femur 
of  T.  orthopygia.  No.  1 325,  American 
Museum  Natural  History. 

While  the  articular  head  of  the 
femur  of  the  form  here  described  is 
damaged  so  that  its  exact  dimensions  ' 
can  not  be  determined,  it  appears  not 
to  have  been  so  large  as  that  of  the 
species  with  which  it  is  here  compared.  On  the  other  hand,  the  digital  fossa  is  much  larger 
than  in  T.  orthopygia,  having  nearly  twice  the  diameter.  It  is  to  be  observed  that  the  diameter 
thru  the  distal  tuberosities  of  the  present  form  is  greater  than  in  the  specimen  of  T.  orthopygia. 
The  type  of  the  latter  species  has  the  distal  end  of  the  femur  63  mm.  wide. 

It  is,  of  course,  possible  that  the  materials  here  described  belong  to  some  already  named 
species  of  Testudo,  but  this  can  be  determined  only  by  future  research. 


P    '     ■               of  femur. 

Diameter. 

Thru 

trochanters. 

1              1 

oL   c                  Thru 
Shaft.            . 

tuberosities. 

mm. 

Testudo     orthopygia.           143 
Undetermined  form.          155 

mm. 

63 
53 

ttim.                  mm. 
24.5                   60 
21                       64 

Testudo  gilbert!   Hay. 
Plate  80,  figs.  2-5. 

Xerohates?  undata,  Gilbert,  Kansas  Univ.  Quart.,  vii,  ser.  a,  1898,  p.  143,  fig.s.  1-4. 
Testudo  gilbertii,    Hay,   Amer.   Geologist,   xxiv,  1899,  p.  349;    Bibliog.  and  Cat.  Foss.  Vert.  N.  A., 
1902,  p.  451- 

The  only  part  of  this  animal  yet  known  is  the  skull,  including  the  lower  jaw.  This  was 
found  in  the  Loup  Fork  deposits  of  Phillips  County,  Kansas,  and  was  described  by  Mr.  J.  Z. 
Gilbert,  who  referred  it  with  some  doubt  to  Cope's  New  Mexican  species,  Xerohates  undata. 
The  latter  was  based  wholly  on  portions  of  the  carapace,  and  there  is  no  evidence  that  the  skull 
belongs  to  the  same  species,  except  that  the  two  occur  in  the  same  formation.  The  skull  has 
suffered  some  injuries.  The  squamosal  and  a  part  of  the  quadrate  on  the  left  side  are  gone, 
thus  exposing  the  tympanic  cavity.  The  pedicels  of  both  quadrates  are  broken  away,  as  well  as 
the  occipital  condyle. 
29 


450  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

The  skull  (plate  80,  fig.  2)  is  rather  narrow.  From  the  front  of  the  tympanic  cavity  the 
sides  converge  slowly  to  the  orbits;  then  more  rapidly  to  the  rounded  snout.  The  height  from 
the  cutting-edge  of  the  maxilla  to  the  level  of  the  frontais  is  contained  in  the  length  to  the 
occipital  condyle  2.5  times.     The  following  are  some  of  the  dimensions: 

Millimeters.  Millimeters. 

Snout  to  occipital  condylr 93  Width  of  interorbital  space 24 

Snout  to  end  of  supraoccipital no  Antero-posterior  diameter  of  orbit 23 

Width  at  base  of  quadrates 66  Width  of  palatine  fossa 23 

Width  at  hinder  ends  of  maxilla' 62 

Seen  from  the  side  (plate  80,  fig.  4)  the  upper  outline  of  the  skull  is  slightly  concave  at  the 
parietals  and  convex  over  the  orbits.  From  the  latter  the  profile  curves  gradually  downward 
to  the  tips  of  the  prefrontals.  The  nasal  opening  is  wider  than  high.  The  prefrontals  meet 
along  the  midline  for  18  mm.,  nearly  the  length  of  the  suture  between  the  frontais.  The  orbits 
are  nearly  circular.  The  jugal  arch  is  narrow,  being  only  7  mm.  wide.  The  maxillary  has  a 
width  of  12  mm.  from  the  orbit  to  the  cutting-edge.  The  latter,  seen  from  the  side,  is  concave 
from  the  premaxillary  to  the  hinder  end.  Any  notches  or  denticles  on  the  premaxillary  were 
small,  if  existent.  The  antero-posterior  extent  of  the  otic  region,  measured  across  the  par- 
occipital  and  the  prootic,  is  only  slightly  more  than  the  extent  of  the  temporal  opening  in  front 
of  the  prootic.  The  supraoccipital  extends  behind  the  line  joining  the  squamosal  processes  of 
the  skull  a  distance  of  13  mm. 

Seen  from  below  (plate  80,  fig.  3)  the  skull  displays  a  highly  vaulted  palate.  The  vomer 
is  highly  archt  in  the  middle  of  its  length,  and  is  traverst  thruout  its  length  by  a  median 
ridge.  The  masticatory  surface  presents  two  prominent  ridges  separated  by  a  groove.  The 
inner  ridge  is  broad  and  rough  behind.  The  outer  is  high  and  sharp,  and  somewhat  tootht. 
It  is  continued  forward  on  the  premaxilla,  being  separated  from  that  of  the  other  side  by  a 
very  distinct  groove.  The  distance  across  the  pterygoids,  where  narrowest,  is  18  mm.  There 
appear  to  have  been  no  ectopterygoid  processes. 

The  lower  jaw  (plate  80,  fig.  5)  is  represented  by  the  co-ossified  dentaries.  The  height  is 
12  mm.  in  front,  13  mm.  behind.  Each  dentary  presents  a  masticatory  surface  having  a  width 
of  9  mm.  This  is  occupied  by  2  ridges  separated  by  a  deep  groove.  The  inner  ridge  is  rough 
and  furnisht  anteriorly  with  small  tooth-like  processes.  The  outer  ridge  has  been  slightly 
serrated,  and  from  the  serrations  low  ridges  run  downward  on  the  outer  surface  of  the  bone. 
The  inner  and  outer  ridges  meet  both  in  front  and  behind,  thus  closing  up  the  groove. 

This  species  resembles  closely  the  one  described  here  as  7.  osborntana,  but  it  differs  in 
several  respects.  The  jugal  arch  is  narrower.  The  antero-posterior  extent  of  the  otic  region  is 
about  equal  to  the  distance  from  the  prootic  to  the  upper  end  of  the  postorbital  arch.  The 
squamosal  processes  are  thin  from  side  to  side,  and  rise  outwardly  to  a  crest  which  stands  over 
the  tympanic  cavity  at  a  level  considerably  higher  than  the  surface  of  the  paroccipital.  The 
whole  skull  seems  to  have  been  of  a  lighter  construction  than  that  of  T .  osborntana.  The  skull 
of  T.  orthopygia  is  relatively  broader,  has  a  considerably  wider  interorbital  region,  a  squamosal 
process  less  comprest  laterally  and  with  a  less  prominent  crest  above.  The  orbit  is  somewhat 
larger  and  the  snout  longer. 

Testudo  edae  Hay. 
Plate  83,  figs.  I,  2. 

Testudo  edce,  Hay,  Ann.  Carnegie  Mus.,  iv,  1906  (1907),  p.  19,  plates  vii,  viii. 

The  single  specimen  which  forms  the  type  of  the  present  species  was  collected  by  Mr.  O. 
A.  Peterson,  of  the  Carnegie  Museum,  in  Loup  Fork,  or  Nebraska,  deposits,  at  Running 
Water,  Sioux  County,  Nebraska.  The  catalog  number  is  1535.  The  specimen  consists  of  a 
carapace  and  plastron  from  which  is  missing  a  portion  of  the  right  side.  Altho  there  has 
occurred  some  crushing  together  of  the  carapace  and  the  plastron,  it  seems  evident  that  even 
in  life  the  shell  was  not  greatly  elevated.  The  middle  region  is  and  was  flat  from  side  to  side, 
as  far  out  as  the  outer  borders  of  the  vertebral  scutes.  Near  the  hinder  border  of  the  first 
vertebral  scute  there  is  a  low  elongated  median  boss.  At  the  sides  and  in  front  of  this  the 
scute  area  is  concave.  The  second  and  third  vertebral  scute  areas  are  likewise  slightly  con- 
cave. Furthermore,  the  areas  of  the  first,  second  and  third  marginal  scutes  are  decidedly 
concave.    The  peripherals  over  the  fore  and  hinder  limbs  flare  upward  somewhat.    The  lower 


TESTUDINID^. 


451 


border  of  the  pygal  is  drawn  in,  as  in  T.  arenivaga.    The  length  of  the  carapace  is  450  mm.; 
the  breadth  was  380  mm. 

The  first  and  third  neurals  are  four-sided;  the  second  and  fourth  are  octagonal;  the  fifth, 
sixth,  and  seventh  are  hexagonal.  There  appear  to  be  only  7  neurals,  of  which  the  table  gives 
the  dimensions. 


Dimensions  of  neurals. 

Dimensions  of  costals. 

Dimensions  of  vertebrals. 

No. 

Length. 

Width. 

No. 

Proximal         Distal 
width,     j     width. 

No. 

I 

2 
3 
4 
5 

Length. 

Width 
in  front. 

Greatest 
width. 

I 
1 
3 
4 
5 
6 

7 

48 
43 

37 
56 
40 

36 
40 

45 

74 
58 

7J 

65 
60 

40 

2 
3 

4 
5 
6 

30                  85 

54               17 
28                  70 
48                  31 
32                  53 

95 
83 
93 
75 
93 

115 
83 

loo 
90 

55 

115 

120 

130 
105 
140 

The  nuchal  is  92  mm.  long,  with  a  maximum  width  of  105  mm.  and  a  frontal  width  of 
73  mm.  All  the  peripherals  are  acute  on  the  free  border,  and  each  presents  a  projecting  point 
at  the  end  of  the  intermarginal  sulcus. 

The  costals  are  strongly  differentiated  as  regards  the  widths  of  the  opposite  ends.  The 
table  presents  their  widths. 

Some  measurements  of  the  pygal  and  the  eleventh  peripheral  are  given  under  the  descrip- 
tion of  T .  arenivaga. 

The  sulci  are  all  narrow  and  they  run  along  on  the  summits  of  low  ridges.  The  dimensions 
of  the  vertebral  scutes  are  shown  above. 

The  plastron  has  a  total  length  of  445  mm.  It  is  concave  especially  in  the  hinder  third,  a 
condition  that  indicates  that  the  individual  was  a  male.  The  anterior  lobe  is  155  mm.  long  and 
205  mm.  wide  at  the  base.  This  width  continues  forward  with  hardly  any  diminution  to  a 
point  in  front  of  the  hyoepiplastral  suture.  The  border  then  rounds  rapidly  to  the  base  of  the 
epiplastral  lip.  The  width  of  the  latter,  at  the  ends  of  the  gulo-humeral  sulci,  is  90  mm.  The 
lip  extends  forward  from  its  base  a  distance  of  55  mm.,  narrowing  rather  rapidly.  The  extrem- 
ity is  slightly  damaged,  so  that  its  exact  form  can  not  be  determined.  The  lower  surface  of  the 
lip  curves  upward  strongly,  like  the  runner  of  a  sled.  The  upper  surface  is  slightly  convex 
from  side  to  side.  The  greatest  thickness  of  the  lip  is  about  25  mm.  On  the  upper  side  the 
thickening  extends  backward  from  the  front  of  the  lip  a  distance  of  105  mm.,  thus  including  the 
front  end  of  the  entoplastron. 

The  length  of  the  entoplastron  is  84  mm.;  the  width,  88  mm.    The  bridge  is  185  mm.  wide. 

The  hinder  lobe  is  112  mm.  long  and  235  mm.  wide  at  the  base.  The  posterior  notch  is 
33  mm.  deep  and  70  mm.  wide.  At  the  inguinal  notch  the  thickness  of  the  hypoplastron  is  30 
mm.     This  becomes  rapidly  reduced  farther  backward. 

The  gulars  overlap  the  entoplastron  about  22  mm.  The  humerals  occupy  80  mm.  of  the 
midline;  the  pectorals,  only  25  mm.;  the  abdominals,  120  mm.;  the  femorals,  60  mm.;  the 
anals,  about  40  mm. 

This  species  is  named  in  honor  of  Mrs.  Eda  Peterson,  wife  of  the  discoverer  of  the  type 
specimen. 

Testudo  hollandi  Hay. 
Plate  84,  figs.  I,  2. 
Testudo  hollandi,  Hay,  Ann.  Carnegie  Mus.,  iv,  1906  (1907),  p.  18,  plates  v,  vi. 

The  type  of  this  species  belongs  to  Carnegie  Museum,  Pittsburg,  and  has  the  catalog 
number  I  561.  It  was  discovered  in  the  upper  beds  of  the  Loup  Fork,  or  Nebraska  beds,  near 
Running  Water,  Sioux  County,  Nebraska,  by  Mr.  O.  A.  Peterson.  The  shell  alone  is  preserved 
and  this  is  somewhat  crusht  downward.  The  carapace  is  broad,  truncated  in  front,  rounded 
behind,  with  the  free  borders  a  little  flaring  over  the  hind  limbs  and  a  little  drawn  in  on  each 
side  of  the  midline  behind.  The  region  along  the  middle  of  the  back  is  rather  flat,  and  pre- 
sents no  traces  of  a  keel.     From  the  free  border  of  the  carapace  in  front  of  the  axillary  notch 


452 


rOSSIL    TURTLES    OK    NORTH    AMERICA. 


a  sharp  carina  passes  backward  over  the  bridge  to  the  free  border  behind  the  inguinal  notch. 
Possibly  the  acuteness  of  this  has  been  accentuated  by  crushing. 

The  plastron  projects  considerably  in  front  of  the  carapace.  This  does  not  appear  to  be 
due  to  any  crushing,  for  the  hinder  end  of  the  plastron  approaches  closely  the  border  of  the 
carapace. 

The  length  of  the  carapace  is  305  mm.;  its  width,  280  mm.  All  the  free  borders  are  acute. 
The  nuchal  has  a  length  of  57  mm.,  a  maximum  width  of  67  mm.,  and  a  width  of  43  mm.  along 
the  free  border.  The  first  neural  is  oval,  the  second  and  fourth  octagonal;  the  third,  fifth,  and 
eighth  are  4-sided;   the  sixth  and  the  seventh,  hexagonal.    The  table  shows  their  dimensions. 


Di 

iiensions  of  neurals. 

Dimensions  of  costals. 

Dimensions  of  vertebrals. 

No. 

Length. 

Width. 

1    No. 

Pioximal         Distal 
width.          width. 

No. 

I       ,^     1     Width 
I'^"^*-    !   in  front. 

Greatest 

width. 

38 

V 

2 

21                    65 

I 

65         1        65 

65 

35 

50 

1      5 

39                 '5 

2 

57         1         57 

83 

28 

43 

4 

22                 58 

) 

60                  73 

9^ 

35 

55 

5 

28                 37 

4 

63                  71 

83 

5 

28 

4« 

*> 

20                 33 

5 

57                 43 

ICO± 

18 

50 

j      7 

17                 26 

7 

»4 

5' 

8 

26 

26 

i 

The  costal  plates  are  alternately  wide  and  narrow  at  their  proximal  ends  and  narrow  and 
wide  at  their  distal  ends.    The  widths  are  given  in  the  table  above. 

The  nuchal  scute  is  15  mm.  long  and  13  mm.  wide.  The  dimensions  of  the  vertebrals  are 
herewith  shown  in  tabular  form. 

The  plastron  has  a  length  of  325  mm.,  being  thus  longer  than  the  carapace.  The  anterior 
lobe  is  100  mm.  long  and  148  mm.  wide  at  the  base.  The  epiplastral  lip  is  70  mm.  wide  at  the 
ends  of  the  gulo-humeral  sulci  and  it  projects  beyond  these  a  distance  of  28  mm.  The  free 
borders  of  the  lobe,  including  the  lip,  are  acute.  The  anterior  border  of  the  lip  is  notcht. 
The  thickening  of  the  lip  is  continued  backward  a  distance  of  45  mm.  from  the  front;  it  then 
drops  off  suddenly,  forming  an  escarpment,  which  is  somewhat  excavated  beneath.  At  the  hyo- 
epiplastral  suture  the  width  of  the  superior  horn-covered  surface  is  27  mm.  The  entoplastron 
IS  6 1  mm.  long  and  58  mm.  wide.    The  bridge  has  a  width  of  150  mm. 

The  hinder  lobe  is  55  mm.  long  at  the  midline,  70  mm.  total,  and  has  a  width  of  155  mm. 
at  the  base.  Median  notch  15  mm.  deep  and  55  mm.  wide.  Near  the  inguinal  notch  the  free 
border  of  the  lobe  is  about  17  mm.  thick;  more  posteriorly  it  becomes  thin  and  finally  acute. 

The  gular  scutes  are  60  mm.  long  in  the  midline.  The  humerals  occupy  54  mm.  of  the 
midline;  the  pectorals,  24  mm.;  the  abdominals,  95  mm.;  the  femorals,  40  mm.;  the  anals, 
33  mm.    The  axillary  and  inguinal  scutes  are  present,  but  small. 

No.  1536  of  the  Carnegie  Museum  is  a  nearly  complete  shell,  smaller  than  the  preceding. 
It  is  referred  to  this  species.     It  presents  the  difference  of  having  a  smaller  epiplastral  lip. 

No.  1570  of  the  Carnegie  Museum  is  also  referred  to  the  present  species.  It  was  obtained 
in  1902,  by  Mr.  Earl  Douglass,  at  Cold  Spring,  Montana,  in  what  the  discoverer  regards  as 
Upper  Loup  Fork  beds. 

The  hinder  parts  of  both  carapace  and  plastron  are  wanting.  The  epiplastral  lip  does  not 
project  so  much  in  front  of  the  carapace  as  in  the  type,  but  this  may  be  due  to  some  distortion. 
The  entoplastron  is  52  mm.  long  and  60  mm.  wide,  differing  thus  somewhat  from  that  of  the 
type,  whose  entoplastron  is  longer  than  wide.     Pectoral  scutes  28  mm.  wide  at  midline. 

The  surfaces  of  this  shell  and  those  of  the  type  are  sculptured  by  the  growth  lines  of  the 
epidermal  scutes. 

This  species  differs  from  T.  farri  in  having  the  first  vertebral  scute  much  less  expanded,  in 
having  the  opposite  ends  of  the  costals  more  narrowed  and  more  widened,  and  the  epiplastral 
lip  more  strongly  developt.  It  differs  from  T.  vaga  in  having  a  more  projecting  epiplastral 
lip,  a  differently  shaped  entoplastron  and  pectoral  scutes  narrower  at  midline. 

This  species  is  dedicated  to  Dr.  W.  J.  Holland,  director  of  the  Carnegie  Museum,  Pitts- 
burg, Pennsylvania. 


TESTUDINID^.  453 

Testudo  turgida  Cope. 

Testudo  turgida,  CoPE,  Proc.  Amer.  Philos.  Soc,  xxx,  1892,  p.  127;  Amer.  Naturalist,  xxvi,  1892,  p.  50; 
3d  Ann.  Report  Geol.  Surv.  Texas,  1891  (1892),  p.  255;  4th  Ann.  Report  Geol.  Surv.  Texas,  1892 
(1893),  p.  47. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  452. — Gidley,  Bull.  Amer. 
Mus.  Nat.  Hist.,  xix,  1903,  p.  627. 

The  type  specimen  of  the  present  species  belongs  to  the  University  of  Texas.  It  was 
discovered  in  the  Blanco  beds  of  the  Pliocene,  near  Espuella,  Dickens  County,  Texas.  No 
figures  of  the  species  have  ever  been  publisht.  The  vifriter  examined  the  materials  in  the 
collection  at  the  University  of  Texas,  at  Austin,  but  was  not  able  to  find  Cope's  type  of  the 
species.  Remains  of  two  or  three  other  specimens  of  the  species  are  in  the  collection,  but  a 
description  of  them  would  add  little  to  what  Cope  has  recorded.  This  author's  description 
is  here  reproduced.  That  found  in  the  Third  Annual  Report,  as  cited  above,  is  identical  with 
that  found  in  the  Proceedings  of  the  American  Philosophical  Society.     It  runs  as  follows: 

This  species  is  represented  by  the  greater  part  of  a  chelonite  of  about  the  size  of  the  Xerobates  agasstzii 
of  Arizona.  It  is  remarkable  for  the  remarkable  depth  of  the  dermal  sutures  and  sculpture  lines,  and 
for  the  swollen  character  of  the  interspaces  which  separate  both.  The  general  shape  is  a  short,  wide 
oval,  with  steep  to  vertical  margins. 

The  plastron  is  widely  emarginate  posteriorly,  and  the  anal-femoral  dermal  sutures  form  a  deep 
notch  in  the  border.  The  anal  scuta  are  oblique  rhomboids,  with  equal  and  nearly  parallel  sides.  The 
median  longitudinal  dermal  suture  is  deep  and  wide,  cutting  half  through  the  thickness  of  the  plastron. 
It  sends  off  a  branch  on  each  side  bounding  the  gular  plates  in  front.  The  part  of  the  plastron  inclosed 
in  the  latter  forms  two  flattened  cones  appressed  together,  whose  vertical  diameter  exceeds  the  transverse, 
and  whose  subconic  apices  are  separated  by  a  deep  notch.  The  interclavicular  bone  is  very  large  and 
is  wide  diamond-shaped,  the  anterior  angle  being  larger  than  the  posterior.  The  transverse  humero- 
pectoral  suture  is  very  deep,  and  is  similar  to  the  median  longitudinal.  The  borders  of  the  anterior  lobe 
are  strongly  convex,  with  a  chord  only  twice  as  long  as  the  lateral  border  of  the  gular  plates. 

The  nuchal  bone  has  a  strongly  concave-emarginate  border.  On  the  posterior  vertebral  bones  is  a 
seat-like  cavity,  which  is  surrounded  by  a  ridge  which  forms  the  greater  part  of  a  circle.  The  costal  bones 
are  unequally  divided  by  the  costal  dermal  sutures,  which  are  very  deep.  Each  costal  scutum  is  divided 
into  two  areas,  one  of  which  is  marked  with  ribs  parallel  to  the  vertebral  axis  at  one  extremity  and  a 
seat-shaped  plane  with  a  bordering  ridge  at  the  other,  which  is  in  some  of  the  costals  smaller  and  more 
swollen.  The  other  half  or  part  of  the  scutal  area  is  swollen  in  the  longitudinal  direction,  but  not  for 
its  entire  length.  The  marginal  bones  are  massive  and  have  a  subacute  border  between  the  bridge  and 
the  median  points.  They  are  much  deeper  than  long,  and  are  deeply  divided  by  the  sutures  which 
separate  the  dermal  marginals.  These  grooves  cut  the  margin  into  deep  notches  at  some  points  and  into 
lower  ones  at  others.  The  areas  between  these  sutures  are  all  .swollen  in  the  same  way  as  the  alternate 
parts  of  the  costal  plates. 

Measurements. 
Millimeters.  Millimeters. 

Length  of  plastron  anterior  to  posterior  angle  of  Diameters  of  free  marginal  near  bridge: 

interclavicle  80  Antero-posterior    20 

Width  of  plastron  anterior  to  posterior  angle  of  Vertical    34 

interclavicle 112  Transverse  below 25 

Length  of  interclavicle 40        Diameters  of  marginal  of  bridge : 

Width  of  interclavicle 58  Antero-posterior    29 

Thickness  of  interclavicle 11  Vertical    44 

Length  of  free  lateral  margin  of  gular  plate 29  Transverse  below 21 

Width  of  base  of  both  gular  plates 45         Diameters  of  penultimate  vertebral  bones: 

Length  of  xiphiplastral  bone 32  Antero-posterior   17 

Width  of  xiphiplastral  bone  on  anterior  suture.  .  .      53  Transverse 30 

Width  of  emargination  of  posterior  lobe  of  plastron     50 

The  American  tortoise  which  has  produced  gular  areas  somewhat  like  those  of  this  species  is  the 
Testudo  cultrata  Cope  of  the  White  River  Neocene  of  Colorado.  That  species  is  however,  totally 
different  in  the  dermal  sutures  of  the  usual  character,  flat  marginals,  etc.,  and  the  gular  proces.ses  are 
not  conic,  but  trihedral  in  form. 

The  speciinen  above  described  comes  from  Espuella,  near  Dockum,  from  the  same  horizon  as 
that  of  Crosby  County,  or  the  Blanco  beds  of  Cummins. 

In  the  Fourth  Annual  Report,  as  cited  in  the  synonymy.  Professor  Cope  stated  that  7 
specimens  of  this  species  were  found  together  at  one  locality,  which  did  not  yield  any  other 
vertebrate  remains.  Fragments  of  2  other  individuals  were  found  at  other  localities  in  direct 
association  with  Mammalia. 


454 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


Testudo  pertenuis  Cope. 

Fig.  609. 

Testudo  pertenuis,  CoPE,  Proc.  Acad.  Nat.  Sci.  Phila.  1892,  p.  226;  4th  Ann.  Report  Geol.  Surv.  Texas, 
1892  (1893),  p.  47,  figs.  I,  2. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  451.— Gidley, 
Bull.  Amer.  Mus.  Nat.  Hist.,  xix,  1903,  p.  627. — Montgomery,  Biol.  Bull.,  viii,  1904,  p.  57. 

The  type  and  only  known  specimen  belongs  to  the  University  of  Texas.    It  was  discovered 
by  Professor  Cope  in  the  year  1892,  in  the  Blanco  beds  of  the  Pliocene,  near  Mount  Blanco, 

Crosby  County,  Texas.  Of  this  species  the  writer 
found  in  the  University  of  Texas  only  three 
or  four  large  fragments  which  had  been  glued 
to  sheets  of  paper.  These  fragments  may  or 
may  not  belong  to  the  type.  The  thickened  por- 
tions of  the  anterior  and  posterior  lobes  of  the 
plastron  appear  not  to  have  been  preserved. 
It  seems  probable  that  the  type  was  injured 
before  being  returned  to  the  collection  at  Austin. 
Under  the  circumstances,  nothing  more  can  be 
done  than  to  republish  Cope's  description  and 
his  apparently  more  or  less  diagrammatic  illus- 
tration (fig.  609).  In  this  figure,  I  represents 
the  carapace  and  part  of  the  front  of  the  plas- 
tron seen  from  above.  The  other  part  of  the 
figure,  2,  shows  the  hinder  lobe  of  the  plastron  as 
seen  from  above. 

Founded  on  a  large  specimen  measuring  three 
and  a  half  feet  in  length  by  three  in  width,  and  re- 
markable for  the  transverse  width  of  the  vertebral 
dermal  scuta.  The  carapace  is  rather  flat  and 
descends  steeply  posteriorly,  the  anal  marginal  bone 
being  somewhat  incurved.  Margins  of  carapace  flare 
outwards  above  the  legs.  The  plastron  has  a  rather 
wide  lip,  with  flat  base  and  straight  lateral  borders; 
its  anterior  border  is  lost.  The  posterior  lobe  is 
deeply  and  widely  notched,  terminating  on  each  side 
in  a  subequilateral  angular  prominence.  Both  cara- 
pace and  plastron  are  without  sculpture,  the  poste- 
rior angles  of  the  plastron  only  being  longitudinally 
grooved  below.  The  vertebral  scuta  are  considerably 

wider  than  long,  as  is  also  the  anal  scutum.     Both  carapace  and  plastron  are  very  thin,  not  exceeding 

one-quarter  inch  in  the  specimen  described,  except  at  the  borders. 


Fig.  609. — Testudo  pertenuis 


C.J.  I,  first  costal  scute;  tnt,  entoplastron;  epi,  epiplastron; 
V.  s.  2,  V.  5.  5,  first  and  fifth  vertebral  scutes.  From 
Copers  figure. 


Measurements. 

Feet. 

Length  over  all 4.2 

Width  over  all 4 

Width  of  penultimate  dorsal  scute i  .275 

Length 85 

Width  of  last  vertebral  scute 1.35 

Width  of  anal  scute 1.5 

Length 5 

Length  of  penultimate  costal  scute 9 


Feet. 

Length  of  last  costal 95 

Width  of  lip  of  plastron  at  base 8 

M'idth  of  anterior  lobe  at  axillae 2 

Width  of  posterior  lobe  of  plastron  at  base 2 

width  at  fundus  of  median  notch i .  i 

Width  at  apices  of  angular  processes 85 

Depth  of  notch 5 


This  is  the  largest  species  of  land-tortoise  yet  known  from  North  America. 

In  its  broad,  deprest  shell,  with  its  broad  vertebral  scutes,  this  species  appears  to  have 
resembled  somewhat  T.  pansa,  of  the  Pawnee  Miocene.  It  differs,  however,  in  several  im- 
portant respects.  The  carapace  of  T.  pertenuis  is  said  to  descend  steeply  behind  and  to  have 
the  pygal  somewhat  incurved.  In  T.  pansa  the  rear  of  the  shell  slopes  gradually  downward 
and  backward,  and  the  pygal  is  not  at  all  incurved.  The  shell  of  T .  pertenuis  is  stated  to  have 
the  borders  flaring  over  the  limbs,  a  condition  not  true  in  T .  pansa.    The  vertebral  scutes  of 


TESTUDINID^.  455 

T.  pertenuis  were  evidently  wider  than  those  of  T.  pansa.  In  the  former  the  penultimate 
vertebral  had  a  width  equal  to  0.36  of  the  whole  length  of  the  carapace;  while  in  T.  pansa  the 
corresponding  scute  has  been  only  0.26  as  long  as  the  carapace.  The  epiplastral  lip  of  T. 
pertenuis  has  had  straight  and,  according  to  Cope's  figure,  parallel  lateral  borders. 

Testudo  catnpester  sp.  nov. 
Figs.  610-613. 

Testudo  catnpester.  Hay,  Bull.  Anier.  Mus.  Nat.  Hist.,  xix,  1903,  p.  627,  in  paper  by  J.  W.  Ciidley  and 
without  description. 

The  remains  on  which  this  species  is  based  were  collected  for  the  American  Museum  of 
Natural  History  during  the  summer  of  1900,  by  Mr.  James  W.  Gidley.  They  were  found  in 
the  Blanco  beds  of  the  Pliocene  deposits,  near  Mount  Blanco,  Crosby  County,  Texas.  The 
materials  all  belong  to  one  individual,  and  consist  of  the  nearly  complete  plastron,  the  lateral 
and  the  posterior  peripherals  from  one  inguinal  notch  to  the  other,  a  portion  of  the  nuchal 
bone,  2  neurals  and  parts  of  a  few  others,  and  portions  of  several  costals.  The  shell  originally 
had  a  length  of  about  730  mm.  and  a  width  of  at  least  560  mm.  It  was  apparently  of  moderate 
convexity  and  of  medium  height.    The  number  of  the  specimen  is  3930. 

The  greater  portion  of  the  plastron  (fig.  610)  is  present,  but  it  has  suffered  some  damage 
thru  decay  of  the  bone  and  loss  of  fragments.  The  total  length  equals  670  mm.  It  is 
somewhat  concave  in  the  hinder  half,  and  the  anterior  lobe  was  lifted  above  the  plane  of  the 
rest  of  the  plastron.  The  length  of  the  anterior  lobe  equals  180  mm.;  its  width,  at  the  axillary 
notch,  has  been  close  to  325  mm.  From  the  axillary  notch  the  outline  of  the  anterior  lobe  is 
moderately  convex  as  far  as  the  gular  suture;  from  this  point  the  outline  changes  its  course 
and  runs  in  a  straight  line  forward  and  inward  to  the  outer  anterior  angle  of  the  lip. 

The  lip  was  quite  prominent.  Owing  to  some  damage  to  the  plastron  in  this  region  its 
width  can  not  be  determined  with  all  desirable  exactness;  but  it  was  very  close  to  125  mm. 
Its  front  is  truncated  or  slightly  convex  and  probably  without  notch;  but  the  portion  present 
does  not  extend  to  the  midline.  The  width  of  the  base  at  the  gular  sutures  was  about  175 
mm.;  the  length  in  the  midline  about  80  mm.  The  upper  surface  is  slightly  convex  from  the 
midline  to  the  lateral  border,  and  this  convexity  is  continued  backward  to  the  posterior  end  of 
each  of  the  epiplastra.  Antero-posteriorly  the  lip  is  very  slightly  convex  above.  The  lower 
side  of  the  lip  is  convex  both  longitudinally  and  transversely.  This  convexity  diminishes 
backward,  so  that  the  hinder  ends  of  the  epiplastra  are  nearly  plane.  The  free  border  of  the 
epiplastra  from  near  the  midline  of  the  lip  to  their  hinder  ends  is  rather  sharply  rounded. 
From  this  border  the  bone  thickens  rapidly,  so  that  at  the  middle  of  the  length  and  breadth  of 
the  epiplastron  the  thickness  equals  46  mm.,  while  at  its  hinder  end  the  thickness  is  37  mm. 

Seen  from  above  the  thickness  of  the  lip  continues  backward  for  about  100  mm.  and  then 
becomes  suddenly  reduced.  Whether  or  not  there  was  an  excavation  behind  the  thickened 
portion  is  uncertain. 

Altho  the  entoplastron  and  the  borders  of  the  epiplastra  joining  it  are  somewhat  eroded, 
it  is  evident  that  the  entoplastron  itself  was  transversely  oval.  Its  transverse  width  was  close 
to  160  mm.;  its  antero-posterior  extent  about  130  mm. 

The  antero-posterior  extent  of  the  hyoplastra  in  the  midline  is  155  mm.  That  of  the  hypo- 
plastra  is  almost  exactly  the  same.  The  xiphiplastra  meet  along  the  midline  for  a  distance  of 
105  mm.    At  their  anterior  ends  each  has  a  width  of  130  mm. 

The  posterior  lobe  of  the  plastron  has  a  total  length  of  105  mm.,  and  it  is  nearly  300 
mm.  wide.  At  its  hinder  extremity  there  is  a  right-angled  notch  whose  width  behind  is  90  mm. 
and  whose  depth  is  45  mm. 

Seen  from  above,  the  posterior  lobe  presents  a  broad,  shallow  basin,  surrounded  at  the 
sides  by  a  bony  wall.  Just  behind  the  inguinal  notch  this  wall  rises,  from  the  lower  side  of  the 
plastron,  to  a  height  of  55  mm.  Here  the  outer  face  of  the  bone  overhangs  somewhat.  Further 
behind,  the  wall  descends,  and  the  outer  face  looks  more  and  more  upward  and  the  summit  of 
the  wall  is  rounded  off.  From  the  posterior  part  of  this  summit  a  low  ridge  runs  to  the  tip  of 
each  of  the  terminations  of  the  plastron. 

Most  of  the  sulci  separating  the  dermal  scutes  of  the  plastron  are  remarkable  for  their 
depth.    Along  the  midline  runs  a  groove  so  deep-as  to  cut  halfway  thru  the  bone,  and  of  about 


456 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


15  mm.  in  width  on  the  hinder  lobe,  and  30  mm.  at  the  junction  of  hyoplastra  and  hypo- 
plastra.  The  width  on  the  entoplastion  can  not  be  determined,  but  it  has  caused  the  latter  to 
break  along  the  midline.  The  gular  sulci  are  not  distinct,  but  they  appear  to  have  been  broad, 
and  they  extended  on  the  entoplastron.  The  humero-pectoral  sulcus  starts,  narrow  and  well 
imprest,  at  the  axillary  notch,  runs  backward  and  inward  nearly  75  mm.,  then  turns  sharply 
and  runs  directly  across  the  plastron,  passing  behind  the  entoplastron.  The  sulcus  between 
the  pectorals  and  the  abdominals  is  convex  forwards.  Laterally  the  pectorals  have  a  width 
of  only  45  mm.,  but  at  the  midline  they  are  75  mm.  wide.  The  abdominals  have  a  width  of 
175  mm.  along  the  midline.  The  sulcus  between  these  and  the  femorals  is  wide  and  deep, 
and  it  runs  directly  across  the  plastron  in  front  of  the  inguinal  notches.  The  femorals  extend 
80  mm.  along  midline.    The  anal  scutes  meet  along  the  midline  for  a  distance  of  about  50  mm. 

The  inner  half  of  the  lower  surface  of  each  hypoplastron  is  markt  by  longitudinal  grooves. 

The  remains  of  the  carapace  (figs.  611,  612,  613)  of  this  species  testify  that  it  is  a  true 
Ti'studo.    One  of  the  neurals  (fig.  611 )  is  octagonal,  and  the  few  costals  present  show  that  some 


610. 


611. 


Figs.  610  and  611. — Testudo  campester.     No.  3930  A.  M.  N.  H. 

610.  Plastron.    Xj.    Partly  restored  in  front. 

611.  Portion  of  anterior  half  of  carapace.    Xj.    Most  of  nuchal  and  whole  of  first  neural  restored. 

were  broad  at  the  proximal  end  and  narrow  distally,  while  others  were  narrow  proximally  and 
wide  distally. 

The  large  octagonal  neural  is  the  second  in  the  series.  Its  fore-and-aft  diameter  along  the 
midline  is  67  mm.;  its  width  across  the  middle  of  the  length  is  86  mm.  The  sides  are  concave, 
the  angles  truncated.  The  third  costal  articulated  with  the  right  hinder  angle  of  the  second 
neural.  Its  greatest  width  is  87  mm.;  its  distal  width  was  about  50  mm.;  its  length  about 
240  mm.    The  second  vertebral  scute  was  about  160  mm.  wide  from  side  to  side. 

There  is  present  the  upper  end  of  another  costal  plate,  probably  the  fourth  on  the  right 
side.  The  upper  end  is  48  mm.  wide;  the  lower  end  of  the  fragment,  perhaps  a  third  of  the 
costal,  is  75  mm.  wide. 

The  proximal  portion  of  the  right  first  costal  is  among  the  remains.  Its  proximal  end  is 
100  mm.  wide  and  most  of  this  is  concave  and  was  in  contact  with  the  first  neural.  The  latter 
must  therefore  have  had  convex  sides.  On  the  outer  half  of  the  upper  surface  of  the  first  costal, 
are  several  deep,  wide,  and  curved  grooves,  which  mark  the  stages  of  growth  of  the  scute 
which  covered  it.  Similar  grooves  are  found  on  other  costals.  The  costals  are  about  13  mm. 
in  thickness. 


TESTUDINID^. 


457 


A  portion  of  the  rear  (fig.  612)  of  the  carapace  along,  and  tor  a  short  distance  on  each  side 
of,  the  midline  is  preserved.  It  includes  the  left  hinder  corner  of  the  hexagonal  sixth  neural. 
This  is  seen  to  have  had  a  width,  across  the  hinder  end,  of  74  mm.  Behind  it  is  a  little  more 
than  the  left  half  of  the  seventh  neural.  This  is  broadest  in  front,  and  hexagonal,  thru  having 
the  anterior  angles  truncated;  and  with  a  maximum  width  of  about  go  mm.  The  fore-and-aft 
extent  was  about  50  mm.  It  is  succeeded  by  the  eighth  neural,  which  has  a  length  of  about 
40  mm.  and  a  width  of  about  45  mm.  Behind  this  is  a  fragment  of  the  first  suprapygal. 
On  it  are  indications  of  the  fourth  and  fifth  vertebral  scutes.  The  exact  length  and  breadth  of 
these  can  not  be  determined.  The  fourth  was  80  mm.  wide  behind  and  the  width  increases 
forward;   while  the  fifth  is  80  mm.  broad  at  its  anterior  end  and  expands  rapidly  backward. 

The  thickened  marginal  portion  of  the  nuchal  bone  (fig.  611)  is  among  the  remains.  Its 
extent  along  the  front  is  about  105  mm.  It  is  slightly  emarginated  at  the  midline,  the  edge  is 
abruptly  rounded  and  from  the  front  it  thickens  rapidly  backward,  until  at  a  distance  of  40  mm. 
from  the  edge  it  is  42  mm.  There  appears  to  have  been  a  nuchal  scute  20  mm.  wide.  It  is 
quite  probable  that  all  the  anterior  peripherals  were  thickened  and  had  obtuse  edges.  Large 
portions  of  the  peripherals  from  the  axillary  notches  backward  are  present.  Those  behind  the 
inguinal  notches  are  higher  than  long;  subacute  at  the  free  borders,  nearly  vertical,  not  flaring, 
except  that  the  second  and  third  on  each  side  of  the  caudal  peripheral  flare  slightly.  The  first 
behind  the  inguinal  buttress  is  160  mm.  high.  Behind  this  the  others  descend,  until  the  pygal 
(fig.  613)  is  115  mm.  high  at  its  lateral  border.    They  are  all  about  80  mm.  long  at  their  free 


612. 


613. 


Figs.  612  and  613. — Testudo  campester.     Portions  of  rear  of  carapace  of  type. 

6ii.  c.f.  8,  eighth  costal  plate  of  type;   n.  7,  n.  8,  seventh  and  eighth  neurals;   sfy,  suprapygal. 
613.  Pygal  and  eleventh  peripherals,    a,  section  of  eleventh  peripheral;   per.  11,  eleventh  peripheral; 


613a. 

xi 


py,  pygal- 

borders.  The  pygal  is  notcht  at  its  upper  border  for  the  second  suprapygal,  95  mm.  wide  at 
this  border,  and  65  mm.  wide  at  the  free  border.  The  thickness  of  the  peripherals  is  about  40 
mm.;  where  they  articulate  with  the  costals  and  the  pygal  the  thickness  is  about  15  mm.  The 
free  border  of  the  peripherals  is  very  slightly  notcht  where  it  is  crost  by  the  sulcus. 

It  is  proper  to  compare  this  species  with  others  which  have  been  described  from  the  Plio- 
cene deposits. 

T.  crassiscutata  (Leidy,  Trans.  Wagner  Free  Inst.,  11,  1899,  p.  31,  plate  vi)  differs  in  having 
the  plastron  much  broader  at  its  hinder  end  and  with  a  much  wider  and  shallower  notch.  The 
lip  of  the  anterior  lobe  is  also  diflFerent. 

T.  hexagonata  Cope,  of  the  Equus  beds  of  Texas  (4th  Ann.  Rep.  Geol.  Surv.  Texas,  1893, 
p.  jy,  plate  xxii,  fig.  2)  has  both  anterior  and  posterior  lobes  of  the  plastron  quite  different. 
Especially  is  it  stated  that  the  sulci  defining  the  pectoral  scutes  in  front  and  behind  approach 
each  other  at  the  midline.    In  T.  campester  these  sutures  are  far  apart  at  the  midline. 

T.  laticaiidata  Cope,  of  the  Equus  beds  of  Texas  (op.  cit.,  p.  75,  plate  xxii,  fig.  i),  has  the 
anterior  lip  of  the  plastron  notcht  in  the  middle  so  as  to  be  doubly  convex,  and  the  lower  side 
of  the  lip  has  two  longitudinal  fossae.  The  posterior  lobe,  with  its  notch,  is  also  different,  the 
notch  being  much  wider  and  much  shallower. 


458 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


T.  pertenuis  Cope,  of  the  Blanco  beds  of  Texas  (op.  cit.  p.  47,  figs.  I,  2),  is  a  large  species 
with  the  bones  of  the  carapace  and  plastron  not  exceeding  about  6  mm.  in  thickness,  except 
at  the  borders.  The  bones  are  also  devoid  of  sculpture.  The  depth  of  the  posterior  notch  at 
the  plastron  is  very  nearly  half  the  width  of  the  plastron  at  the  bottom  of  the  notch.  In  T. 
campester  the  depth  of  the  notch  is  not  one-third  of  the  width  of  the  plastron  at  the  point 
indicated.  The  vertebral  scutes  of  T .  pertenuis  were  much  wider  than  in  T .  campester.  Those 
of  our  specimen  of  the  latter  would  be  about  250  mm.  wide  if  their  ratio  to  the  length  of  the 
animal  were  the  same  as  in  T .  pertenuis. 

T.  turgida  (Proc.  Amer.  Philos.  Soc,  xxx,  1892,  p.  127)  has  not  been  figured.  It  also  is 
from  the  Blanco  beds  of  Texas.  So  far  as  known  it  is  a  small  species.  The  anterior  lip  is 
described  as  resembling  two  "flattened  cones  apprest  together,  whose  vertical  diameter  exceeds 
the  transverse  and  whose  subconic  apices  are  separated  by  a  deep  notch."  Relatively  to  the 
size  of  the  animal  the  hinder  plastral  notch  was  much  wider  than  it  was  in  T.  campester.  Other 
important  differences  appear  on  comparison  of  the  descriptions. 


Testudo  obtusa  (Leidy). 

Figs.  614,  615. 

Eupachemys  obtusus,  Leidy,  Jour.  Acad.  Nat.  Sci.  (2),  viii,  1877,  p.  232,  plate  xxxiv,  figs.  4,  5. — Hay, 

Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,   1902,  p.  448. 
Eupachemys  rugosus,  Leidy,  Trans.  Wagner  Free  Instit.,  11,  1889,  p.  29  (errore). 

Dr.  Leidy's  Eupachemys  obtusus  was  based  on  a  single  peripheral  bone  which  was  sent 
to  him  by  Prof.  F.  S.  Holmes,  this  bone  having  been  found  in  the  phosphate  beds  of  Ashley 
River,  South  Carolina.  The  exact  age  of  the  fossil  is  impossible  of  determination;  but  its  time 
of  existence  was  undoubtedly  somewhere  between  the  end  of  the  Eocene  and  the  beginning  of 
the  Pleistocene.  Dr.  Leidy  founded  for  this  turtle  the  new  genus  Eupachemys,  but  he  did  not 
attempt  to  define  it.    This  name  and  the  fact  that  he  compared  the  bone  with  a  peripheral  of 

Emys  seem  to  indicate  that  he  believed 
the  relationships  of  the  animal  to  be 
with  the  aquatic  emyds.  The  bone 
was  evidently  derived  from  a  turtle 
about  a  meter  in  length.  None  of  the 
Emydidae  attains  such  great  size,  and 
without  other  evidence  the  probability 
would  be  that  the  animal  was  a  species 
of  Testudo.  To  this  genus  it  is  here 
referred.  There  are  some  reasons  for 
suspecting  that  it  is  the  same  turtle 
that  was  later  described  by  Leidy 
under  the  name  Testudo  crassiscutata. 
However,  until  more  is  known  about 
the  two  forms  it  seems  best  to  retain 
them  distinct. 

Dr.  Leidy  regarded  the  bone  de- 
scribed by  himself  as    probably   the 


614. 


615. 


Figs.  614  and  615. — Testudo  obtusa. 
of  type  peripheral. 


Outline  and  section 

xj. 

614.  Outline  of  upper  surface.  615.  Section  at  posterior  end. 

eighth  of  thejeft  side.  If  this  were  true  the  anterior  end  might  be  expected  to  be  thicker 
than  the  posterior;  but  of  this  we  have  no  evidence.  The  fore-and-aft  extent  of  the  bone 
(fig.  614)  is  120  mm.  The  height  at  the  posterior  end  is  136  mm.;  the  greatest  thickness, 
72  mm.  At  the  costal  border  the  bone  is  thinned  down  to  15  mm.  The  lower,  or  free,  border 
(fig.  615)  is  obtuse,  a  rare  condition  in  turtles.  What  Leidy  regarded  as  the  upper  surface,  and 
probably  correctly,  rises  in  a  prominent  fore-and-aft  ridge  just  below  the  middle  of  the  height. 
From  this  ridge  to  the  costal  border  the  surface  is  concave;  from  the  ridge  to  the  free  border, 
it  is  plane.  The  lower,  or  inner,  surface  is  strongly  convex  from  the  costal  to  the  free  borders. 
The  upper  surface  of  the  bone  is  rough  and  eroded.  It  exhibits  no  sulci  separating  the 
marginal  scutes.  The  inner  surface  is  smooth  and  presents  a  longitudinal  sulcus  running 
along  near  the  costal  border  and  more  feeble  indications  of  another  that  ran  between  the  two 


TESTUDINID^. 


459 


marginal  scutes  which  occupied  the  bone.  In  fig.  615,  which  represents  the  posterior  end  of  the 
peripheral,  the  outer  surface  is  toward  the  left  hand. 

In  the  collection  of  turtle  remains  from  Peace  Creek,  Florida,  Dr.  Leidy  found  a  thick  and 
rounded  peripheral  which  he  thought  (Trans.  Wagner  Free  Inst.,  11,  p.  29)  might  belong  to 
his  earlier  publisht  Eupachemys  obtusa,  which  he  referred  to  mistakenly  under  the  name 
Eiipachemyi  rugosus. 

In  the  collection  of  the  U.  S.  National  Museum  at  Washington  there  is  a  large  peripheral 
which  was  collected  by  Dr.  W.  H.  Dall  at  Caloosahatchie,  Florida.  It  has  a  length  of  145  mm. 
The  costal  border  is  broken  oiF.  The  free  border  is  obtuse.  The  greatest  thickness  is  37  mm. 
It  is  possible  that  it  belongs  to  the  present  species. 

Testudo  crassiscutata  Leidy. 
Figs.  616-624. 

Testudo  crassiscutata,  Leidy,  Trans.  Wagner  Free  Instit.,  n,  1889,  p.  31,  plate  vi,  figs.  4-7;   Bull.  U.  S. 
Geol.  Surv.,  No.  84,  1892,  p.  129. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  451. 

The  materials  described  by  Dr.  Leidy  under  the  above  name  consisted  of  a  number  of 
fragments  of  one  individual,  mingled  with  a  few  fragments  of  the  shells  of  two  others.  These 
remains  indicated  a  tortoise  whose  carapace  measured  about  1520  mm.  in  length.  The 
specimens  are  now  in  the  U.  S.  National  Museum  and  have  the  number  986.  They  were 
discovered  in  the  Peace  Creek  beds,  at  Arcadia,  Florida.  As  the  type  those  bones  must  be 
taken  which  were  figured  by  Dr.  Leidy.    These  are  the  greater  portion  of  the  right  epiplastron. 


Figs.  616  and  617. — Testudo  crassiscutata. 
Portions  of  plastron  of  type.     X  J- 


616.  Portion  of  anterior  lobe. 


Portion  of  hinder  lobe. 


617. 


616. 


wrongly  mentioned  by  Leidy  as  the  left,  a  portion  of  the  right  hyoplastron,  the  thickened 
borders  of  the  hinder  lobe  of  the  plastron,  the  left  femur,  and  the  left  tibia. 

The  anterior  lobe  of  the  plastron  (fig.  616)  had  a  length  of  280  mm.,  measured  at  the  mid- 
line, and  a  width  close  to  475  mm.  at  the  base.  Dr.  Leidy  gives  the  width  as  520  mm.;  but  he 
measures  outward  to  the  middle  of  the  axillary  notch.  From  the  base  the  lobe  narrows  rapidly 
to  the  front,  where  the  width  is  about  80  mm.  The  lip  does  not  project  beyond  the  general 
curvature  of  the  lobe,  but  it  does  project  beyond  the  ends  of  the  gulo-humeral  sulci.    From  the 


460  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

subacute  free  border  of  the  lip  the  bone  rises  on  the  upper  side  to  a  point  105  mm.  behind  the 
front  and  then  drops  off  suddenly.  The  greatest  thickness  attained  is  70  mm.  The  upper 
surface  of  the  lip  is  convex.  There  is  no  conspicuous  notch  where  the  gulo-humeral  sulcus 
crosses  the  border. 

The  entoplastron  was  about  245  mm.  wide.  Its  length  is  conjectural.  It  was  pointed  in 
front.  Its  greatest  thickness  at  the  midline  is  70  mm.,  while  the  thickness  of  the  hyoplastron 
is  46  mm. 

The  hinder  lobe  (fig.  617)  had  a  length  of  about  160  mm.  along  the  midline  and  a  basal 
width  of  about  530  mm.  Posteriorly  there  is  a  median  notch  220  mm.  wide  and  only  45  mm. 
deep.  At  the  inguinal  notch,  on  the  upper  surface  of  the  lobe,  a  great  wall  begins  and  runs 
backward  along  the  free  border.  The  outer  face  of  this  wall  is  perpendicular  and,  at  the 
notch,  100  mm.  high.  At  the  femoro-anal  sulcus  the  height  is  40  mm.,  and  the  outer  face  is 
inclined  at  an  angle  of  about  45°.  From  the  beginning  the  inner  face  slopes  at  an  angle  of 
about  45°. 


Jigs.  618-620. — Testudo  crassisiutnta.     Neurals  and  costals.     X  J- 
6i8.  Third  and  fourth  neurals.  619.  Costal  bone.  620.  Costal  bone. 

In  the  U.  S.  National  Museum  is  a  collection  of  fossil  tortoise  bones.  No.  4963,  which  were 
collected  near  Tampa,  Florida,  by  Mr.  A.  M.  Lambert.  They  are  believed  to  belong  to  this 
species.  There  are  2  successive  neurals,  the  third  and  the  fourth  (fig.  6i8).  They  are  remark- 
able for  their  size  and  great  thickness.  The  third  has  a  length  of  about  1 10  mm.  and  a  width 
of  155  mm.  It  is  crost  by  a  deep  sulcus.  From  each  end  of  the  bone  the  surface  slopes  toward 
this  sulcus,  so  that  the  bottom  of  the  latter  is  15  mm.  below  the  level  of  the  ends  ot  the  bone. 
The  fourth  neural,  like  that  of  most  other  species  of  the  genus,  is  much  larger  than  the  third 
and  is  octagonal  in  form.  Its  length  is  130  mm.;  its  width,  200  mm.;  and  its  thickness,  44 
mm.  Each  side  was  in  contact  with  the  third,  fourth,  and  fifth  costals.  An  estimate  makes  it 
probable  that  the  carapace  of  this  individual  was  about  4  feet  in  length. 

Fig.  619  represents  the  proximal  end  of  a  costal  belonging  to  this  collection,  either  the  third 
or  the  fifth.  Its  greatest  width  is  150  mm.,  but  at  the  distal  end  of  the  fragment  the  width  is 
reduced  to  1 11  mm.    At  the  proximal  end  the  thickness  is  40  mm.    Here  it  was  in  contact  with 


TESTUDINID^. 


461 


3  neurals.  The  median  vertebral  scutes  of  this  individual  must  have  been  about  240  mm. 
long  and  about  300  mm.  wide.  A  costal  bone  (fig.  620)  very  similar  to  this  was  figured  by  Dr. 
Leidy  in  F.  S.  Holmes's  Post-Pliocene  Fossils  of  South  Carolina,  plate  xxviii,  fig.  i.  This 
was  secured  from  the  Ashley  River  deposits  and  its  age  is  uncertain.  It  now  belongs  to  the 
American  Museum  of  Natural  History.  Its  size  is  almost  the  same  as  that  of  the  costal  just 
described.  The  thickness  is  33  mm.  It  appears  to  belong  to  the  present  species,  and  to  furnish 
evidence  that  7.  crassiscutata  lived  during  the  time  when  T.  (Eupachemys)  obtusa  existed. 
On  the  other  hand.  Dr.  Leidy  (Trans.  Wagner  Free  Instit.,  11,  p.  29)  mentions  the  finding, 
among  bones  collected  at  Peace  Creek,  Florida,  of  a  peripheral  that  resembled  that  forming 
the  type  of  T .  obtusa.  There  is  no  certainty  that  T.  obtusa  and  T.  crassiscutata  are  not  one  and 
the  same  species,  but  for  the  present  it  may  be  better  to  regard  them  as  distinct.  With  the 
neurals  and  the  costal  of  No.  4693  of  the  U.  S.  National  Museum  there  is  a  posterior  peripheral. 
Its  fore-and-aft  extent  is  1 15  mm.  The  height,  following  the  curvature,  is  220  mm.  It 
curves  upward  as  the  free  border  is  approacht.  This  border  is  acute.  The  greatest  thickness  of 
the  bone  is  35  mm.  Prof.  F.  W.  Putnam  has  given  to  the  American  Museum  of  Natural 
History  some  turtle  bones  that  were  dredged  in  the  Alifia  River,  Florida.  The  beds  are 
probably  of  the  same  age  as  the  Peace  Creek  beds.  Among  these  is  a  large  peripheral,  the 
length  of  which  along  the  free  border  is  148  mm.     Fig.  621  represents  a  section  of  this  bone. 


621.  622f.  622«. 

Figs.  621  and  622. — TestuJo  crassiscutata. 

621.  Section  across  a  hinder  peripheral.    Xj.    No.  6094  A.  M.  N.  H. 

622.  Left  epiplastral  of  young  individual.    X§.    a,  upper  surface;    h,  section  of  symphysis;   r,  lower  surface. 

As  will  be  seen,  it  is  much  turned  upward  toward  the  free  border.  The  thickness  is  35  mm. 
The  free  edge  is  acute.  It  is  possible  that  the  obtuse  peripheral  forming  the  type  of  T .  obtusa 
belonged  to  the  anterior  part  of  the  carapace,  while  the  acute-edged  peripherals  just  described 
belonged  posteriorly.  Another  peripheral  from  the  Alifia  River  has  a  thickness  of  48  mm. 
Its  free  border  is  eroded  away;    but  as  far  as  represented  the  upper  surface  is  concave. 

The  Jarman  collection  of  fossil  bones,  made  in  Hillsboro  County,  Florida,  and  now  in 
Vanderbilt  University,  contains  a  left  epiplastron  which  is  referred  with  some  doubt  to  this 
species  (fig.  622,  a,  b,c).  If  it  is  correctly  identified  it  belongs  to  a  relatively  young  and  small 
individual.  The  greatest  length  of  the  bone  is  82  mm. ;  the  bone  of  type  of  the  species  was  270 
mm.  long.  The  feature  in  which  the  present  specimen  differs  from  that  of  the  type  is  the  great 
thickness  of  the  bone  where  it  joined  the  epiplastron  of  the  other  side.  In  the  type  the  greatest 
thickness  of  the  epiplastron  is  70  mm.  If  the  present  specimen  retained  the  same  proportions 
its  thickness  would  be  21  mm.  It  is,  however,  37  mm.  thick.  There  is  more  or  less  variation 
in  these  beaks  among  the  Testudos  and  for  the  present  it  seems  best  to  refer  this  specimen  to 
Leidy's  species.  In  the  same  collection  is  a  peripheral  that  appears  to  be  the  right  ninth,  with 
the  costal  border  broken  away.  This  peripheral  has  a  length  of  154  mm.  along  the  free  border. 
The  greatest  height  of  the  bone,  as  preserved,  is  186  mm.  and  this  does  not  extend  beyond  the 


462 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


costo-marginal  sulcus.  Where  thickest,  at  the  line  where  on  the  inner  surface  the  horny  scute 
met  the  soft  skin,  the  bone  is  45  mm.;  elsewhere  from  22  mm.  to  30  mm.  Considering  the 
great  thickness  of  the  neurals  and  costals  we  might  expect  the  peripherals  of  T .  crassiscntata 
to  be  thicker  than  is  the  bone  here  described. 


Testudo  laticaudata  Cooe. 
Figs.  623,  624.. 

Testudo  laticaudata,  CoPE,  Gaol.  Surv.  Texas,  iv,  1903,  reprint  p.  75,  plate  xxii,  fig.  I. — Hay,  Bibliog. 
and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  451. 

The  type  of  Cope's  T.  laticaudata  consists  of  a  nearly  entire  right  epiplastron,  said  by 
Cope  to  be  the  left,  and  the  greater  part  of  the  right  xiphiplastron.  These  remains  were  found 
by  Prof.  W.  F.  Cummins,  of  the  Texas  Geological  Survey,  in  the  Equus  beds,  on  Rock  Creek, 
opening  into  Tule  Canyon,  in  Briscoe  County,  Texas.  These  bones  are  now  in  the  Univer- 
sity of  Texas,  where  the  writer  has  been  permitted  to  examine  them. 

The  form  of  the  anterior  lobe  of  the  plastron,  as  far  backward  as  the  hyoepiplastral 
suture,  can  be  seen  from  Cope's  figure  here  reproduced.  The  width  of  the  lobe  at  the  suture 
mentioned  was  very  close  to  205  mm.  The  epiplastral  lip  was  very  slightly  set  off  from  the 
remainder  of  the  lobe  and  was  rounded  and  slightly  tootht  in  front.  The  lower  surface  of  the 
bone  is  in  general  flat,  but  on  the  lip  there  are  two  broad  shallow  fossae.  The  free  border  is 
acute  posteriorly,  less  so  in  front  of  the  gulo-humeral  sulcus.  Along  the  epiplastral  symphysis 
the  bone  thickens   rapidly  (fig.  624)  rising  to  a  height  of  about  42  mm.     It  then  descends 


624. 


Figs.  623  and  624. — Testudo  laticaudata. 

623.  Right  epiplastral   and    xiphiplastral  bones  forming  type.    Xj.         a,  right  epiplastron,  lower  surface; 

b,  upper  surface  of  same  bone;    c,  lower  surface  of  right  xiphiplastron;   d,  upper  surface  of  same  bone. 

624.  Section  along  symphysis  of  epiplastral  bones.    Xs* 

perpendicularly  until  a  thickness  of  about  20  mm.  is  attained.  At  the  hyoepiplastral  suture 
the  thickness  of  the  bone  has  become  reduced  to  19  mm.  Along  the  suture  mentioned  the 
thickness  is  at  first  reduced  slowly,  then  rapidly  to  the  acute  free  border.  The  width  of  the 
bone  along  this  suture  is  54  mm.  The  entoplastron  had  a  width  of  about  100  mm.  Its  length 
can  not  be  determined. 

On  the  lower  side  of  the  bone  is  seen  a  portion  of  the  gulo-humeral  sulcus.  It  crost  the 
entoplastron,  then  ran  outward  and  forward,  then  outward  and  slightly  backward  to  the  free 
border  of  the  bone. 

Figure  623  <r,  J,  reproduces  Cope's  figures  of  the  right  xiphiplastron,  the  part  on  the  right 
representing  the  upper  side  of  the  bone,  that  on  the  left  the  lower  side.  At  the  hypoxiphi- 
plastral  suture  the  free  border  is  rather  obtuse.  From  the  border  the  bone  thickens  rapidly  to 
a  thickness  of  25  mm.  Further  backward  the  free  border  becomes  acute  and  the  maximum 
thickness  slightly  less.  At  the  midline  behind  it  is  23  mm.  The  hinder  angle  of  the  bone  is 
curved  slightly  upward.  The  horn-covered  surface  on  the  upper  face  of  the  bone  reaches  the 
free  border  at  a  distance  of  15  mm.  from  the  midline.    The  posterior  notch  was  about  120  mm. 


TESTUDINID.*:. 


463 


wide.  On  the  lower  surface  of  the  bone  is  seen  the  femoro-anal  sulcus,  running  parallel  with 
the  hinder  border  of  the  bone.  The  area  occupied  by  the  anal  scute  is  rough  and  it  occupies 
a  slightly  different  level  from  the  rest  of  the  bone. 

As  stated  by  Cope,  this  species  may  belong  to  the  genus  Gopherus  (Xerobates),  but  this 
can  not  be  determined  before  the  skull  has  been  found. 

Testudo  hexagonata  Cope. 
Figs.  625,  6i6. 

Testudo  hexagonata,  CoPE,  Geol.  Surv.  Texas,  iv,  1903,  reprint  p.  77,  plate  xxii,  fig.  2. — HAY.Bibliog. 
and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  451. — Gidley,  Bull.  Amer.  Mas.  Nat.  Hist.,  xix,  1903, p.  623. 

The  present  species  is  based  on  a  specimen  now  in  the  University  ot  Texas,  at  Austin, 
Texas,  where  the  writer  has  been  permitted  to  study  it.  The  specimen  was  found  by  Prof.  W.  F. 
Cummins,  of  the  Texas  Geological  Survey,  in  the  Equus  beds,  on  Rock  Creek,  a  stream 
emptying  into  Tule  Canyon,  in  Briscoe  County,  Texas. 

The  carapace  of  this  shell  is  considerably  crusht  and  fractured,  and  somewhat  weathered. 
Various  parts  of  the  free  border  are  missing.  It  is  therefore  difficult  to  secure  the  details  of  the 
structure,  and  this  portion  of  the  shell  was  not  described  by  Cope.  A  figure  is  here  presented 
(fig.  626)  which  gives  as  well  as  could  be  determined  the  structure  of  the  carapace. 


626. 


Figs.  625  and  626. — Testudo  hexagonata.     Shell  of  type. 
625.  Half  of  lower  surface  of  shell.    From  Cope's  figure.    Xj.  626.  Carapace,  partly  restored.    Xj. 

The  length  of  the  carapace  is  380  mm.;  the  width,  330  mm.  The  peripherals  in  front  and 
behind  the  bridge  appear  not  to  have  been  flared  upward  to  any  considerable  extent.  Poste- 
riorly the  carapace  appears  to  have  been  steep.  Not  much  can  be  determined  regarding  the 
arrangement  of  the  neurals,  on  account  of  distortion.  The  first  had  a  width  of  about  45  mm. 
The  second  is  octagonal,  with  a  length  of  45  mm.  and  a  width  of  nearly  70  mm.  The  third 
was  4-sided.  The  second  costal  bone  is  narrowed  proximally  and  greatly  widened  distally, 
being  here  about  65  mm.  wide.  The  fourth  and  sixth  costals  have  a  similar  form.  The  third 
and  fifth  are  widened  proximally  and  narrowed  at  the  distal  ends. 


464  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

The  vertebral  scutes  are  wide  and  strongly  angulated  where  their  lateral  boundaries  join 
the  intercostal  sulci.  The  first  is  130  mm.  wide  anteriorly  and  70  mm.  wide  behind.  The  others 
have  a  maximum  width  of  about  130  mm. 

The  plastron  was  described  and  figured  by  Cope.  His  drawing  is  here  reproduced  (fig.  625). 
When  in  Cope's  hands  the  epiplastral  lip  was  present,  but  this  is  now  missing.  The  length  of 
the  plastron  is  given  by  Cope  as  365  mm.  This  included  the  extremities  of  the  hinder  lobe  on 
each  side  of  the  notch.  The  anterior  lobe  has  a  width  of  about  180  mm.  and,  according  to 
Cope,  a  length  of  89  mm.  Cope  states  that  the  epiplastral  lip  had  a  simple  regularly  rounded 
outline,  which  was  distinctly  set  oflFfrom  the  rest  of  the  anterior  border.  From  his  description, 
confirmed  by  the  impression  on  the  matrix,  the  lip,  at  the  symphysis,  thickened  rapidly  back- 
ward on  the  upper  surface.  A  section  along  the  symphysis  would  closely  resemble  that  of  T . 
laticaudata.  The  thickness  reacht  was,  according  to  Cope,  27  mm.  The  width  of  the  lip  at 
the  base  was  90  mm.;  the  length  on  the  midline  of  its  upper  surface,  40  mm.  The  hinder  face 
of  the  thickening  was  excavated  to  form  a  thoracic  cavity.  Posteriorly  the  epiplastra  were 
greatly  reduced  in  thickness,  nowhere  along  the  hyoepiplastral  suture  exceeding  11  mm.  The 
bone  thins  gradually  to  the  free  border,  so  that  the  hinder  part  of  the  epiplastron  differs  con- 
siderably from  that  of  T .  laticaudata. 

The  entoplastron  was  of  hexagonal  form,  about  60  mm.  long  and  80  mm.  wide.  The 
bridge  has  a  width  of  180  mm.  The  width  of  the  hinder  lobe  may  be  regarded  as  200  mm. 
Cope  gives  it  as  240  mm.,  but  he  measures  to  the  middle  of  the  inguinal  notches.  The  length, 
to  the  extremities  of  the  hinder  angles  of  the  xiphiplastra,  is  100  mm.  The  notch  behind  is 
about  80  mm.  wide. 

The  gular  scutes  extended  well  backward  on  the  entoplastron.  The  humerals  extend  11 
mm.  behind  the  entoplastron,  on  the  midline.  The  pectorals  join  at  the  midline  a  distance  of  22 
mm.;  the  abdominals,  a  distance  of  120  mm.;  the  femorals,  a  distance  of  42  mm.;  the  anals, 
a  distance  of  40  mm. 

The  free  border  of  the  xiphiplastron  is  acute  from  the  hinder  angle  to  near  the  hypoxiphi- 
plastral  suture.  As  the  latter  is  approacht  the  bone  thickens  to  25  mm.  and  the  free  border 
becomes  obtuse. 

Cope  states  this  species  may  belong  to  the  genus  Gopherus  {Xerobates),  but  this  can  not 
be  settled  before  the  skull  is  found. 

Testudo  atascosse  Hay. 

Figs.  627-628. 

Testudo  atascoste,  Hay,  Proc.  Acad.  Nat.  Sci.  Phila.  1902,  p.  383,  figs.  1-5. 

In  the  collection  of  the  Academy  of  Natural  Sciences  of  Philadelphia  the  writer  has  found 
certain  bones  which  belong  apparently  to  an  undescribed  species  of  the  genus  Testudo.  These 
bones  are  accompanied  by  a  label  to  this  effect :  "Miocene,  E.  W.  Marnock,  Atascosa  County, 
Texas."  There  is  no  record  of  how  this  material  came  to  the  Academy.  Mr.  Witmer  Stone  has 
suggested  that  it  may  have  been  derived  from  Dr.  Leidy's  collection;  we  know  also  that  Mr. 
G.  W.  Marnock  collected  in  Atascosa  County,  Texas,  for  Professor  Cope,  but  beyond  this 
there  is  no  indication  that  these  bones  were  ever  in  the  hands  of  either  Professor  Cope  or  Dr. 
Leidy.    The  initial  "E"  in  the  name  above  given  is  probably  an  error  for  G. 

These  remains  consist  of  the  left  half  of  the  anterior  lobe  of  the  plastron  and  the  greater 
portion  of  the  left  side  of  the  hinder  lobe.    Figures  of  these  parts  are  presented  (figs.  627,  628). 

The  species  was  one  of  considerable  size.  The  xiphiplastron  had  a  length  of  about  no  mm., 
the  whole  posterior  lobe  a  length  approximately  of  120  mm.  The  anterior  lobe  had  about  the 
same  length.  We  may  perhaps  safely  estimate  200  mm.  for  the  length  of  the  bridge,  thus  mak- 
ing the  plastron  440  mm.  long. 

The  anterior  lobe  (fig.  627)  was  close  to  200  mm.  in  width.  The  entoplastron  had  a  width 
of  100  mm.;  its  length  was  probably  about  80  mm.,  but  its  hinder  border  is  missing.  The 
gular  scutes  encroach  on  its  anterior  border.  A  broad  rounded  lip  projected  beyond  the  gulo- 
humeral  sulci  about  28  mm.  It  had  a  width  of  80  mm.,  and  is  not  notcht  in  front.  The  whole 
border  of  the  anterior  lobe  is  acute,  thru  the  beveling  off  of  the  upper  side.  Figure  627  repre- 
sents a  section  thru  the  lip  at  the  midline  and  shows  this  beveling.     The  greatest  thickness  at 


TESTUDINID^. 


465 


the  lip  is  23  mm.;  at  a  point  halfway  to  the  axillary  notch  this  thickness  is  reduced  to  only 
21  mm.;  near  the  notch  it  is  about  10  mm.  Superiorly  the  lip  extends  back  about  50  mm. 
From  the  summit  of  the  lip  two  ridges,  with  a  shallow  valley  between  them,  run  toward  the 
axillary  notch,  diverging  gently.  There  was  evidently  no  thoracic  excavation  in  the  hinder 
face  of  the  lip. 

The  posterior  lobe  (fig.  628)  was  broadly  notcht  behind,  the  notch  having  a  width  of  about 
90  mm.  and  a  depth  of  35  mm.  The  terminal  lobules  are  directed  outward  and  upward,  ear- 
like, somewhat  as  they  are  in  Gopherus  polyphemus,  but  not  so  narrow  as  they  are  in  the  latter. 
From  the  midline  behind,  the  border  is  acute  around  the  lobules  and  as  far  forward  as  about 
35  mm.  behind  the  hypoxiphiplastral  suture.  Here  it  rather  suddenly  becomes  broadly  rounded 
as  shown  by  the  cross-section  (fig.  628a).  At  the  suture  mentioned  the  thickness  of  the  bone 
is  30  mm.     The  wall  thus  formed  continues  backward,  descending  somewhat,  and  meets  the 

627a. 


627.  628.  6284. 

Figs.  627  and  628. — TestuJo  atascoste.     Plastron  of  type.     X  i- 

627.  Anterior  lobe;   a,  section  of  epiplastral  symphysis. 

628.  Hinder  lobe;   a,  section  at  hypoxiphiplastral  suture;   b,  at  extremity  of  xiphiplastron. 

midline  15  mm.  or  more  in  front  of  the  bottom  of  the  notch.  Fig.  628A  presents  also  a  section 
thru  one  of  the  lobules  in  a  direction  from  its  tip  toward  the  center  of  the  hinder  lobe.  The 
greatest  thickness  is  22  mm. 

The  femoro-anal  sulcus  runs  from  the  midline  outward,  so  as  to  make  the  outer  end  of  the 
anal  scute  somewhat  wider  than  the  mesial  end.  Antero-posteriorly,  at  the  middle  of  its  width, 
the  scute  is  40  mm.  long. 

The  deposits  in  which  this  tortoise  was  found  belong  to  the  Equus  beds  of  the  Pleistocene. 

In  the  same  region  Mr.  Marnock  collected  Terrapene  marnocht  (Cope)  and  Trachemys 
hisornata  (Cope)  (Proc.  Amer.  Philos.  Soc,  xvii,  1878,  pp.  228,  229;  Amer.  Naturalist, 
XXIII,  1889,  p.  161). 

It  is  not  improbable  that  this  species  belongs  to  the  genus  Gopherus. 

Superfamily  TRIONYCHOIDEA. 

Thecophora  with  skull  and  neck  in  all  essential  respects  like  the  same  parts  in  the  Crypto- 
dira.  Horny  jaws  concealed  beneath  fleshy  lips.  Peripheral  bones  rarely  present.  Plastron 
ligamentously  connected  with  the  carapace.  Epiplastra  separated  from  the  hyoplastra  by  the 
entoplastron.  Pelvis  not  suturally  connected  with  the  carapace  and  plastron.  ,  So  far  as  known, 
no  epidermal  scutes. 

Of  the  Trionychoidea,  2  families  are  here  recognized — the  Trionychidae  and  the  Plasto- 
menidae.    The  former  family  is  represented  by  numerous  living  species;   the  latter  is  extinct. 

In  his  Bibliography  and  Catalogue  of  the  Fossil  Vertebrata  of  North  America,  constitut- 
ing Bulletin  No.  179  of  the  U.  S.  Geological  Survey,  publisht  in   1902,  the  author  regarded 

30 


4.66  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

the  Trionychoidea  as  one  of  three  suborders  of  the  Testudines,  the  other  two  being  the  Athecae 
and  the  Thecophora.  Further  consideration  of  the  subject  has  convinct  him  that  the  group 
is  too  closely  related  to  the  Cryptodira  to  justify  such  a  wide  separation  of  the  two.  On  the 
other  hand,  there  are  structural  differences  of  too  great  value  to  permit  the  trionychids  to  be 
reduced  to  the  status  of  one  or  two  families  under  the  Cryptodira.  It  is  now  believed  that  their 
relationships  to  other  turtles  will  be  correctly  exprest  by  making  them  a  superfamily  of  the 
Thecophora,  the  other  superfamilies  being  the  Amphichelydia,  the  Cryptodira,  and  the 
Pleurodira.  This  classification  is  that  adopted  by  Dr.  Boulenger  in  his  Catalogue  of  Chelon- 
ians,  etc.,  in  the  British  Museum. 

For  a  discussion  of  the  structure  and  relationships  of  the  trionychids  the  reader  is  referred 
to  Baur's  papers  in  the  Zoologischer  Anzeiger,  vol.  x,  1887,  p.  96;  vol.  xi,  1888,  p.  736;  vol.  xii, 
1889,  pp.  241-243,  and  American  Naturalist,  vol.  xxiv,  1870,  p.  530;  Dr.  Boulenger's  catalog 
referred  to  above,  and  to  a  paper  by  the  present  writer  (Bull.  Amer.  Mus.  Nat.  Hist.,  xi, 
1905,  pp.  137-175).  For  a  discussion  of  Haeckel's  view  that  the  Trionychoidea  are  the  most 
primitive  of  the  Thecophora  the  reader  is  referred  to  page  25  of  the  present  work. 

The  geographical  distribution  of  the  living  Trionychidae  is  discust  on  page  35  and  is 
illustrated  by  fig.  16. 

Family  PLASTOMENID.a;  Hay. 

Trionychoidea  with  skull  like  that  of  the  Trionychidae.  Neck  unknown,  but  probably 
like  that  of  the  Trionychidae.  No  peripheral  bones.  Epiplastra  separated  from  the  hyoplastra 
by  the  large,  crescentic  entoplastron.  Hyoplastra,  hypoplastra,  and  xiphiplastra  closely  united, 
as  in  the  Emydidae.     Feet  unknown. 

Up  to  the  present  time  only  one  genus  is  known  which  may  be  referred  to  this  family — • 
the  genus  Plastomenus  Cope.  The  structure  of  this,  so  far  as  determined,  has  been  learned 
from  the  Bridger  species.     The  cervical  vertebrae  and  the  feet  are  unknown. 

The  Plastomenidae  differ  from  the  Trionychidae,  so  far  as  known,  principally  in  the 
structure  of  the  plastron.  In  the  latter  family  the  ventral  armor  differs  much  from  that  of  the 
Cryptodira.  The  bones  have  suffered  reduction,  so  that  great  fontanels  intervene  between  the 
bones  of  the  opposite  sides  and  between  the  entoplastron  and  the  hypoplastra.  The  ento- 
plastron is  V-shaped  and  excludes  the  epiplastra  from  the  hypoplastra.  In  the  Plastomenidae 
the  three  hinder  pairs  of  bones  join  their  fellows  closely  at  the  midline,  as  in  the  Cryptodira, 
and  the  hypoplastra  are  closely  sutured  to  the  hyoplastra  and  to  the  xiphiplastra.  There 
appears  to  have  been  little  space  between  the  entoplastron  and  the  hypoplastra.  Indeed,  the 
plastron  is  more  completely  closed  than  in  the  Chelydridae  and  Cheloniidae.  Furthermore, 
the  entoplastron,  if  we  may  form  our  conclusion  from  Plastomenus  ceJemius,  was  broad  fore 
and  aft  and  elongate  kidney-shaped.  We  do  not  know  what  were  the  form  and  connections  of 
the  epiplastra. 

A  peculiarity  of  structure  displayed  by  some  species  of  the  family  is  the  great  development 
of  the  eighth  pair  of  costals.  In  most  species  of  Trionychidae  the  eighth  costals  are  greatly 
reduced  and  in  some  cases  wholly  wanting.  In  Plastomenus  thomasi  and  some  other  species 
this  pair  of  costals  is  greatly  developt.  The  character  does  not,  however,  appear  to  be  shared 
by  all  the  species. 

Genus  PLASTOMENUS  Cope. 

At  the  present  time  the  generic  characters  oi  Plastomenus  can  not  be  separated  from  those 
assigned  above  to  the  family.  So  far  as  known  there  is  present  a  preneural  bone,  and  some  of 
the  hinder  neurals  are  wanting. 

Type:    Plastomenus  thomast  Cope. 

Professor  Cope's  first  definition  of  the  genus  Plastomenus  (Proc.  Acad.  Nat.  Sci.  Phila. 
1873,  p.  278)  is  hardly  sufficient  to  distinguish  it  from  other  trionychids.  For  a  reason  which 
the  present  writer  does  not  understand  he  concluded  that  there  was  present  "a  nuchal  marginal 
which  does  not  exist  in  Trionyx,"  but  no  such  bone  has  been  shown  to  have  existed.    He  was 


PI.ASTOMENID^.  467 

especially  struck  by  the  configuration  of  the  inner  end  of  the  hyoplastral  bone,  which  appeared 
to  him  greatly  different  from  that  of  Trionyx;  but  he  does  not  mention  the  condition  of  the 
median  and  hinder  portions  of  the  plastron. 

In  1877  (Wheeler's  Surv.  looth  Merid.,  iv,  p.  47),  Cope  concluded  that  the  hyoplastrals 
were  not  greatly  different  from  those  of  Trionyx,  while  the  hypoplastrals  were  materially 
different.  They  are  stated  to  have  displayed  a  transverse  width  behind  the  inguinal  region 
more  hke  an  emydoid  than  a  trionychoid  genus.  The  more  extended  ossification  of  all  these 
bones  in  Plastonienus  than  in  other  genera  of  trionychids  was  recognized.  Cope's  remarks 
on  the  genus  in  the  work  referred  to  were  copied  into  his  work  of  1884  on  the  vertebrates  of  the 
Tertiary  formations. 

Even  as  late  as  the  year  1882  (Amer.  Naturalist,  xvi,  991)  Professor  Cope  was  uncertain 
whether  or  not  this  genus  belonged  to  the  Emydidae. 

Several  of  the  species  referred  to  this  genus  are  based  on  very  fragmentary  and  incomplete 
materials,  and  it  is  not  improbable  that  when  more  complete  remains  shall  have  been  dis- 
covered some  of  these  species  will  have  to  be  placed  in  other  genera. 

Analysis  of  Species  Referrkij  to  Plastomenus. 

A^.  Judith  River  and  Laramie  species: 

1.  Costals  with  angular  pits,  5  in  10  mm.,  and  crost  by  prominent  welts costatus 

A^.  Arapahoe  species: 

2.  Costals  without  welts;   pits  fine,  not  angular,  6  in  10  mm punctulatus 

3.  Costals   not  known;     free   border  of  hypoplastron   acute;    lower  surface  with 

angular  pits insignis 

/f'.  Puerco  or  Torrejon  species: 

4.  Carapace  with  welts.     Carapace  and  plastron  with  small  pits acupictus 

A*.  Wasatch  species: 

5.  Like  P.  thomasi,  but  ridges  between  pits  broader;   7  pits  in  a  line  15  mm.  long         catenalus 

6.  Costals  thick;  pits  on  distal  ends  of  costals  in  rows;  3  or  4  pits  in  a  line  of  10  mm.        leptomitus 

7.  Costals  thick;  sculptured  with  pits  and  welts;   pits  circular,  7  on  10  mm lachrymnlis 

8.  Costals  of  moderate  thickness,  pits  angular,  7  in  10  mm;  some  of  the  intervening 

ridges  weltlike jractus 

g.   Pits  of  costals  abruptly  sunken;    5  in   10  mm.  ;   no  welts;    plastron  with  ver- 

miculate  ridges corrugatus 

10.  Costals  thick;  pits  circular,  4  in  10  mm.;  oblique  welts  on  some  costals;  plastron 

with  rows  of  circular  pits communis 

A".   Bridger  species: 

11.  Carapace  with  welts  and  pits;   four  pits  in  a   10  mm.  line.     Costals  of  eighth 

pair  as  long  as  wide thomasi 

12.  Carapace  with  welts  and  pits;    five  or  six  pits  in  10  mm.;  eighth  costals  much 

shorter  than  broad visendus 

13.  Carapace  with  welts  and  pits;    eight  pits  in  10  mm.;    hinder  costals  about  as 

long  as  wide tunttllus 

14.  Carapace  with  welts  on  hinder  end;   three  or  four  pits  in  10  mm wdemius 

15.  Like  oedemius  but  with  from  five  to  seven  pits  in  10  mm molopin 


us 


Plastomenus  costatus  Cope. 
Plate  85,  figs.  1,  2. 

Plastomenus  costatus,  Cope,  Vert.  Cret.  Form.  West,  1875,  pp.  94,  261,  plate  viii,  fig.  8;  Proc.  Acad. 
Nat.  Sci.  Phila.  1875,  p.  9;  Brit.  N.  A.,  Bound.  Comm.  Report  on  Geol.  etc.,  1875,  p.  337. — Hay, 
Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  452. — Hatcher,  Bull.  U.  S.  Geol.  Surv.  No.  257,  p.  74. 

This  species  was  described  from  materials  collected  by  Dr.  G.  M.  Dawson,  south  of  Wood 
Mountain,  Assiniboia.  The  deposits  from  which  they  were  derived  were  supposed  to  belong 
to  the  Laramie,  but  are  now  known  to  belong  to  the  Judith  River.  These  materials  are  now 
the  property  of  the  Geological  Survey  of  Canada.  They  consist  of  a  piece  of  a  costal,  a  frag- 
ment of  probably  the  right  hypoplastron,  and  another  small  undetermined  fragment.  The 
costal  fragment  was  figured  by  Cope  as  cited.    The  bone  is  remarkable  for  the  relative  thick- 


468  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

ness  of  the  portion  occupied  by  the  rib.  Some  of  Cope's  measurements  appear  to  be  sHghtlv 
erroneous.  The  thickness  of  the  edge  of  the  bone  is  nowhere  quite  5  mm.;  where  thinnest 
only  3  mm.  The  thickness  thru  the  rib  is  a  Httle  less  than  9  mm.  The  border  of  the  plastral 
fragment  is  10  mm.  thick.  The  ornamentation  of  the  surface  of  the  costal  is  distinct  and 
peculiar.    There  are  about  5  of  the  angular  pits  in  a  line  10  mm.  long. 

The  fragment  of  the  plastron  appears  to  be  a  portion  of  the  right  hypoplastron  extending 
from  the  inguinal  notch  backward.  There  are  some  indications  that  it  extended  to  the  xiphi- 
plastral  suture.     The  free  border  is  rounded. 

There  are  in  the  American  Museum  some  portions  of  a  carapace  and  a  plastron  which 
were  collected  by  Mr.  Barnum  Brown  in  1902,  in  Laramie  deposits,  12  miles  south  of  the 
Missouri  River,  on  Hell  Creek.  The  locality  is  130  miles  west  of  Miles  City,  Montana.  It  is 
not  certainly  known  that  the  various  bones  belong  to  the  same  individual.  Their  number  in 
the  American  Museum  is  6131.  Figure  i  of  plate  85  represents  the  distal  end  of  one  costal, 
as  seen  from  the  upper  surface.  The  thickness  at  the  articular  border  is  5  mm.;  that  thru  the 
rib  is  8  mm.  In  this  specimen,  as  in  Cope's  type,  the  rib  stands  out  on  the  lower  surface  of 
the  bone  with  great  distinctness.  It  likewise  extended  a  considerable  distance  beyond  the  free 
border  of  the  costal.  These  borders  are  beveled  off  obliquely  to  the  upper  surface.  The 
ornamentation  consists  of  a  network  of  ridges,  which  anastamose  irregularly  and  inclose  pits 
and  winding  and  interrupted  valleys.  The  ridges  are  rather  low,  and  there  are  from  4  to  6 
of  them  in  a  line  10  mm.  long.  On  the  costal  plate  here  figured  we  find  2  welts  crossing  it, 
such  as  we  find  in  P.  thomasi.    Another  costal  does  not  show  these. 

Figure  2  of  plate  85  represents  the  right  xiphiplastron.  A  comparison  of  this  bone  with  that 
of  P.  thomasi  will  reveal  many  similarities.  There  is  no  doubt  that  this  bone  articulated  with 
the  one  of  the  opposite  side  thruout  its  entire  length.  At  the  anterior  end  of  this  median  border 
there  are  two  processes  which  entered  pits  in  the  opposite  bone  and  received  between  them  a 
process  from  that  opposite  bone.  The  anterior  border  also  almost  certainly  articulated  its  full 
length  with  the  hypoplastron.  At  the  outer  anterior  angle  there  are  two  strong  processes 
for  digitation  with  the  hypoplastron.  At  the  base  of  these  processes  the  thickness  is  12  mm.; 
while  at  the  median  border  the  thickness  is  5  mm.  The  sculpture  of  the  bone  agrees  well  with 
that  of  the  portion  of  plastron  described  by  Cope.  It  is  similar  to  that  of  the  carapace  but  the 
pits  are  not  so  deeply  imprest.     It  covers  the  whole  lower  surface  of  the  bone. 

Plastomenus?  punctulatus  Cope. 

?Plastomenus  punctulatus,  CoPE,  Ann.  Report   U.  S.  Geol.  and  Geog.  Surv.  Terrs.,  1873  (1874),  p.  45J; 

Bull.  U.  S.  Geol.  and  Geog.  Surv.  Terrs.,  I,  No.  2,  1874,  p.  29;  Vert.  Cret.  Form.  West,  1875,  pp.  94, 

261,  plate  vi,  fig.  9. 
?Plastomenus  punctulatus,  Cope,  Bull.  U.  S.  Geol.  and  Geog.  Surv.  Terrs.,  m,  1877,  p.   575. 
Plastomenus  punctulatus.  Hay,   Bibliog.  and  Cat.   Foss.  Vert.  N.  A.,  1902,  p.  453. — Hatchkr,  Bull. 

U.  S.  Geol.  Surv.,  No.  257,  1905,  p.  74. 

Cope's  type  of  the  present  species  consists  of  only  a  fragment  of  a  costal  plate,  which  the 
describer  figured  in  his  monograph  on  Cretaceous  vertebrates,  as  cited  above.  This  type  is 
now  in  the  American  Museum  and  has  the  catalog  number  1845.  It  was  collected  in  north- 
eastern Colorado,  in  association  with  the  type  of  Trionyx  vagans  Cope;  and  therefore  on 
Bijou  Creek,  in  deposits  believed  by  Whitman  Cross  to  belong  to  the  Arapahoe  formation. 
Professor  Hatcher,  as  cited  above,  thought  that  the  type  locality  was  doubtful,  because  Cope, 
in  his  latest  description  (Vert.  Cret.  Form.  West,  p.  94)  says  that  the  species  was  "established 
on  a  costal  bone  in  association  with  the  preceding  species,"  and  the  "preceding  species" 
there  is  Plastomenus  costatus,  of  the  Judith  River  beds  of  British  America.  This  comes  from 
Cope's  having  transferred  without  change  his  original  description,  which  was  preceded  by 
his  Trionyx  vagans,  to  his  monograph,  where  it  was  preceded  by  Plastomenus  costatus.  There 
can  be  no  doubt  whatever  that  the  present  species  was  found  on  Bijou  Creek,  Colorado.  The 
type  is  accompanied  by  a  label  in  Cope's  handwriting  as  follows:  "Plastomenus  punctulatus, 
10-9-1873,  Colorado."  Cope  states  that  he  had  examined  several  fragments  of  the  same 
species  that  had  been  collected  by  Dr.  Hayden  at  Long  Lake,  in  the  present  state  of  North 
Dakota;  but  at  present  we  can  not  depend  on  the  determination. 


PLASTOMENID^.  469 

No  additional  material  having  been  discovered,  we  can  do  little  more  than  reprint  Cope's 
description: 

Established  on  a  costal  bone  found  in  association  with  the  preceding  species,  and  referred  to  the 
genus  Plastomenus  provisionally,  and  with  a  probability  that  it  will  be  found  not  to  pertain  to  it  when 
fully  known.  That  genus  has  so  far  only  been  found  in  the  Eocene  formation.  The  bone  is  rather  thin 
and  sufficiently  curved  to  indicate  a  convex  carapace  of  moderate  thickness.  The  surface  is  marked 
with  closely  packed  shallow  pits  without  material  variation  of  form  on  the  proximal  end  of  the  bone. 
The  result  is  an  obsolete  sculpture  quite  similar  to  that  seen  in  some  species  of  the  genus  to  which  it 
is  at  present  referred. 

Measurements. 

Meter. 

Width  of  costal  bone o .  0250 

Thickness  of  costal  bone 003;; 

Number  of  pits  in  o.oio  meter,  6. 

Lignite  Cretaceous  of  Colorado;  also  several  fragments  from  Long  Lake,  Nebraska,  from  Dr. 
Hayden. 

It  will  be  observed  that  the  pits  of  this  carapace  are  small,  and  measurements  made  on 
the  specimen  show  that  there  are  sometimes  seven  pits  in  a  line  10  mm.  long.  The  thick- 
ness of  the  bone  at  the  neural  border  is  nearly  5  mm.;  thru  the  swelling  caused  by  the  rib  on 
the  under  side,  it  is  5  mm.     Cope's  measurement  was  taken  at  the  sutural  border. 

The  type  locality  being  known,  it  does  not  appear  necessary  to  despair  of  finding  and 
identifying  other  specimens  of  this  trionychid. 

It  is  possible  that  this  species  belongs  to  the  genus  Plastomenus,  but  of  this  we  can  not  be 
assured  before  additional  carapacial  materials  shall  have  been  found  accompanied  by  the 
plastron. 

Plastomenus?  insignis  Cope. 

Plastomenus';'  insignis,  Cope,  Ann.  Report  U.  S.  Geol.  and  Geog.  Surv.  Terrs.,  187J  (1874),  pp.  433,454; 
Bull.  U.  S.  Geol.  and  Geog.  Surv.  Terrs.,  I,  No.  2,  1874,  p.  29;  Vert.  Cret.  Form.  West,  1875,  pp.  95, 
261,  plate  vi,  fig.  10.— Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  452.— Hatcher,  Bull. 
U.  S.  Geol.  Surv.  No.  257,  1905,  p.  75. 

This  species  was  based  on  a  single  fragment  of  the  hypoplastron,  presenting  a  part  of  the 
free  border  of  the  hinder  lobe  close  to  the  inguinal  notch.  This  type  belongs  to  the  American 
Museum  of  Natural  History  and  has  the  number  1846.  It  is  accompanied  by  a  label  in  Cope's 
handwriting  as  follows:  "Plastomenus  insignis.  10-9-1873,  Colorado."  In  his  description 
Cope  states  that  this  specimen  was  found  in  the  same  locality  as  his  P.  punctulatus;  and  as 
shown  under  the  latter  species,  page  468,  this  locality  was  somewhere  on  BijouCreek,Colorado. 
The  formation  is  believed  to  be  the  Arapahoe.  Professor  Hatcher  regarded  the  type  locality 
as  doubtful,  and  this  species  as  therefore  worthless  from  a  biological  and  a  stratigraphical 
point  of  view.  There  can  be  no  doubt  about  the  type  locality,  and  the  present  writer  believes 
that  it  will  be  possible  to  identify  other  materials  coming  from  this  locality  and  having  the  same 
part  present. 

The  fragment  has  a  length  of  23  mm.  and  a  width  of  1 1.5  mm.  It  extends  forward  to  the 
suture  with  the  hyoplastron  and  backward  nearly,  if  not  actually,  to  the  suture  with  the 
xiphiplastron.  The  acute  free  border  of  the  bone  extends  forward  within  10  mm.  of  the 
hyohypoplastral  suture.  This  fact  shows  that  the  species  must  have  been  a  small  one, 
perhaps  not  more  than  150  mm.  long.  At  the  suture  with  the  hyoplastron  the  bone  is  4 
mm.  thick. 

Cope  states  that  the  suture  with  the  xiphiplastron  was  gomphosial.  At  the  hinder  end  ot 
the  bone  there  is  a  smooth  pit  which  may  have  received  a  process  from  the  xiphiplastron. 
The  writer  can  not  convince  himself  that  any  other  part  of  the  suture  is  present.  There 
is  no  excavation  of  the  free  border  for  a  forwardly  directed  process  of  the  xiphiplastron,  such 
as  we  might  have  expected. 

The  specimen  affords  no  characters  that  confirm  or  that  refute  the  reference  of  the  species 
to  the  genus  Plastomenus. 


47° 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


1907,  p.   852,  plate    liv,  figs   l-j; 


r--- 


L--- 


FlG.  629. — Plasfomenus  acupictus. 
Plastron  of  type.     X  i. 


Plastomenus  acupictus  Hay. 
Fig.  629. 

Plastomenus   acupictus.  Hay,   Bull.  Amer.   Mus.   Nat.   Hist.,  xxiii, 
text-fig.  8. 

The  fragmentary  remains  of  this  species  are  a  part  of  the  Cope  collection  in  the  American 
Museum  of  Natural  History.    The  catalog  number  is  1025.     The  bones  were  collected  for 

Professor  Cope  many  years  ago,  apparently  from  Torrejon 
deposits,  in  New  Mexico,  by  Mr.  David  Baldwin.  The 
individual  was  a  small  one. 

A  costal  bone,  believed  to  be  the  third,  is  10  mm.  wide 
and  3  mm.  thick  at  the  neural  border.  The  seventh  costal 
is  16  mm.  wide  at  the  distal  end,  3  mm.  thick  at  the  sutural 
edge,  and  4.5  mm.  thru  the  ridge  formed  by  the  rib. 

On  the  hinder  costals  are  seen  6  or  7  welts.  The  pits 
covering  all  the  upper  surface  except  the  beveled  free  bor- 
der, are  unusually  small,  there  being  5  in  a  line  5  mm.  long. 

The  hinder  lobe  had  a  width  of  about  60  mm.  at  the 
base.  The  suture  between  the  hypoplastron  and  the  xiphi- 
plastron  (fig.  629)  is  27  mm.  long.  At  the  bridge  the  hypo- 
plastron is  8  mm.  wide  and  5  mm.  thick.  As  in  other 
species  of  the  genus,  there  seem  to  have  been  no  fontanels 
on  the  midline  of  the  plastron. 

There  are  no  welts  on  the  plastral  bones  and  the  pits 
are  somewhat  smaller  than  on  the  carapace. 

Plastomenus  catenatus  Cope. 
Plate  86,  fig.  i. 

Plastomenus  catenatus.  Cope,  Syst.  Cat.  Vert.  Eocene  New  Mexico,  p.  35;  Ann.  Report  Chief  Engineers, 

1875,  Append,  ll,  p.  1016  (of  reprints,  p.  96). 
Plastomenus  multtfoveatus,  CoPE,  Wheeler's  Report  Surv.  West  looth  Merid.,  1877,  iv,  p.  49,  plate  xxv, 

fig.  II. 

The  fragment  of  costal  plate  on  which  Cope  based  the  present  species  is  in  the  U.  S. 
National  Museum  and  bears  the  number  1 138.  It  was  discovered  in  the  Wasatch  Eocene 
beds,  in  the  region  of  the  Gallinas  River,  New  Mexico.  When  Cope  came  to  figure  the  speci- 
men, in  1877,  he  had  come  to  the  conclusion  that  it  belonged  to  a  species  that  he  had  already 
described  from  the  Bridger  beds  of  Wyoming,  a  species  which  he  called  P.  multtfoveatus,  but 
which  is  here  described  as  P.  thomasi.  The  present  writer  has  examined  the  type  of  P.  catenatus 
and  has  become  convinct  that  it  belonged  to  a  species  distinct  from  the  Bridger  form  men- 
tioned. As  the  fragment  has  already  been  named,  figured,  and  described,  it  appears  to  be 
best  to  retain  for  it  the  original  name  and  await  the  finding  of  additional  materials  from  the 
type  locality.    Cope's  figure  of  the  fragment  is  reproduced  on  plate  86,  fig.  i. 

The  piece  of  costal  is  25  mm.  wide,  4  mm.  thick.  The  ridges  separating  the  pits  are 
wider  than  in  the  case  of  P.  thomasi,  and  the  slope  into  the  pits  is  more  abrupt.  In  a  line  15 
mm.  long  there  are  7  of  the  pits.     In  some  cases  two  or  more  of  them  appear  to  have  coalesct. 

Plastomenus?  leptomitus  (Cope). 
Plate  86,  fig.  z;   teit-fig.  630. 

Trionyx  leptomitus,  CoPE,  Syst.  Cat.  Vert.  Eocene  New  Mexico,  1875,  p.  35;  Append,  ll,  Ann.  Report 
Chief  Engineers,  1875,  p.  1015  {separata,  p.  95);  Wheeler's  Surv.  W.  looth  Merid.,  iv,  1877,  p.  44, 
plate  xxv,  figs.  27-31,  plate  xxvi,  figs.  1-4.;  Vert.  Tert.  Form.  West,  1884,  p.  118. — King,  U.  S. 
Geol.  Explor.  40th  Parallel,  Syst.  Geol.,  I,  1878,  p.  377. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N. 
A.,  1902,  p.  454. 

The  known  remains  of  this  species  were  collected  by  Professor  Cope  in  the  year  1874,  in 
deposits  belonging  to  the  Wasatch  formation,  in  Rio  Arriba  County,  New  Mexico.  These 
specimens  are  now  in  the  U.  S.  National  Museum,  at  Washington,  and  bear  the  numbers 


PLASTOMENID^.  4/1 

1 1 10  and  1 1 13,  the  specimens  appearing  on  Cope's  plate  xxvi  having  the  latter  number. 
Professor  Cope  states  (Syst.  Cat.,  p.  35)  that  4  individuals  were  represented  in  his  collection. 
All  these,  it  yet  present,  are  included  under  the  catalog  numbers  just  given.  The  originals 
of  Cope's  figs.  I,  2,  and  3,  of  his  plate  xxvi,  were  considered  by  him  to  constitute  the  type  of 
the  species,  and  are  said  to  belong  to  a  single  individual.  Fig.  i  represents  the  outer  end  of 
the  left  hypoplastron;  fig.  2,  apparently  a  fragment  of  the  left  hypoplastron  at  the  bridge; 
while  Cope's  fig.  3  is  the  distal  end  of  a  costal.  In  Cope's  fig.  2  the  left  side  represents  the 
sutural  border  for  articulation  with  the  hyoplastron,  and  the  concave  edge  on  the  upper  right- 
hand  side  is  the  inguinal  notch,  which  is  here  quite  acute.  If  this  identification  of  the  bone  is 
correct,  the  notch  was  more  abruptly  formed  than  is  usual  in  species  of  Trionychidae,  and 
quite  as  abruptly  as  in  Flastomenus  thomasi.  In  order  to  understand  the  relations  of  the  bones 
represented  by  the  two  figures,  fig.  2  must  be  conceived  as  being  removed  to  the  left  of  fig.  i 
in  such  a  way  that  the  left  edge,  the  sutural  one,  shall  be  turned  90  degrees  and  placed  about 
parallel  with  the  upper  border  of  fig.  i .  When  the  two  figures  are  thus  placed,  there  should  be 
perhaps  about  35  mm.  of  space  between  their  lower  borders.  Fig.  630  represents  these  bones 
in  the  position  suggested. 

The  fragment  of  costal  plate  represented  by  Cope's  fig.  3,  plate  xxvi,  has  a  thickness  of 
10  mm.    The  figure  is  reproduced  (plate  86,  fig.  2).    The  upper  surface  is  beveled  off  some- 
what and  the  upper  layer  of  bone  overhangs  the  deeper 
p^^^ — -^  layers.    The  upper  surface  of  the  bone  is  sculptured  with 

(  \ narrow  ridges  which  run  parallel  with  the  free  border  ot 

the  costal.  Between  these  sharp  ridges  are  furrows, 
which  are  occasionally  divided  into  pits  by  intersecting 
ridges.  There  are  4  of  these  furrows  in  a  distance  ot 
10  mm.  One  fragment  of  the  upper  end  of  a  costal  is 
found  with   the  type.     It  shows  the  rib-head  and  was 

,  ,-  u,    ,  ;    .      ■.        orieinallv  about   20   mm.  wide.     The  thickness  at  the 

riG.    bm. — rlastomenus    leptomitus.  ,    ,        .       ■     ^  .  1        -i    •     ■  t^i 

Combination  of  two  of  Cope's  fig-    sutural   border  is  6  mm.;  thru  the  rib  it  is  7  mm.    The 

ures  to  show  their  relative  positions,    angle  between  the  articular  border  for  the  corresponding 

Xj.    No.  1113  U.  S.  N.  M.    Type,    neural  and  that  for  the  outer  hinder  angle  of  the  neural 

next  in  front  shows  that  the  neurals  were  much  wider 
behind  than  in  front.  The  upper  25  mm.  of  the  upper  surface  is  covered  with  large  irreg- 
ular pits,  about  3  in  10  mm.  Distally  they  become  smaller.  It  is  possible  that  this  tragment 
does  not  belong  to  this  species,  but  other  fragments  appear  to  form  the  transition  to  the 
original  of  Cope's  fig.  3,  plate  xxvi. 

The  fragments  which  belonged  to  Cope's  third  specimen,  and  which  furnisht  figs.  27  to  31 
of  his  plate  xxv,  belonged  to  a  larger  animal.  It  is  possible,  too,  that  they  belonged  to  a 
distinct  species.  As  in  the  type,  the  costal  is  thickened  distally  and  the  sculpture  consists  ot 
ridges  crossing  the  costal  and  connected  at  intervals  by  intersecting  ridges.  In  the  type  ot  the 
species  the  ridges  are  of  nearly  uniform  size  or  perhaps  they  increase  slightly  in  breadth  and 
distance  apart  toward  the  free  margin  of  the  costal.  In  the  third  specimen,  however,  they  are 
broader  and  more  obtuse  and  they  become  distinctly  narrower  and  more  crowded  toward 
the  margin,  as  is  shown  in  Cope's  figures.  Furthermore,  the  sculptured  layer  of  the  type 
overhangs  the  deeper  layers,  at  the  free  margin,  more  than  it  does  in  the  originals  of  Cope's 
figs.  29-31.  All  these  differences  may,  however,  be  due  to  variations  in  age  and  size  or  to 
varying  positions  in  the  carapace. 

In  the  lot  of  bones  representing  this  species  there  is  a  portion  of  a  plastron,  apparently  a 
part  of  the  left  hypoplastron  from  the  inguinal  region,  and  hence  corresponding  to  the  piece 
represented  by  Cope's  fig.  2,  plate  xxvi.  This  presents  a  sculpture  in  which  the  ridges  run  at 
right  angles  with  the  hyohypoplastral  suture.  At  this  suture  the  thickness  is  8  mm.,  but  nearer 
the  free  border  it  is  15  mm.  An  outer  extremity  of  a  hypoplastron  in  the  lot  shows  a  sculpture 
different  from  that  of  the  type  individual,  and  more  like  that  of  Amyda  ventricosa. 

More  and  much  better  materials  are  needed  in  order  to  determine  the  structure  and 
relationships  of  this  tortoise.  The  form  of  the  hypoplastron  of  the  type  and  to  some  extent 
the  sculpture  of  the  carapace  seem  to  indicate  that  the  species  belongs  to,  or  is  near,  the  genus 
Plastomenus. 


472  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

Plastomenus  ?  lachrymalis  Cope. 
Plate  86,  fig.  3. 

Plastomenus  lachrymalis,  CoPE,  Append.  FF,  Ann.  Report  Chief  of  Engineers,  1874,  p.  603  {oi  separata, 
p.  96);  Syst.  Cat.  Vert.  Eocene  N.  Mex.,  1875,  p.  35;  Wheeler's  Surv.  W.  looth  Merid.,  IV,  pt.  II, 
1877,  pp.  48,  51,  plate  XXV,  figs.  7-7*;  Vert.  Tert.  Form.  West,  1884,  p.  123. — Hay,  Bibliog.  and 
Cat.  Foss.  Vert.  N.  A.,  1902,  p.  452. 

This  insufficiently  known  species  was  secured  by  Cope  in  the  Wasatch  deposits  of  New 
Mexico.  It  was  based  on  a  single  individual  and  apparently  on  only  fragments  of  costal  plates. 
Of  these  2  were  figured.  These  remains  were  evidently  referred  to  Plastomenus  because  of 
the  character  of  the  sculpture.  We  can  not  be  sure  of  the  correctness  of  this  assignment  before 
similar  costals  shall  have  been  found  associated  with  the  plastral  bones.  The  writer  does  not 
know  where  the  specimen  now  is. 

Professor  Cope's  description  is  given  below,  and  one  of  his  figures,  that  of  the  distal  end 
of  a  costal  bone,  is  reproduced  on  the  plate  referred  to  above.  The  part  of  the  figure  indicated 
by  a  shows  the  thickness  of  the  bone. 

Costals  with  finer  pits  [than  in  P.  serialis],  the  welts  broken  into  tubercles  posteriorly. 

The  largest  species  of  the  genus  represented  in  the  Eocene  of  New  Mexico.  The  costal  bones  are 
rather  finely  punctate,  the  posterior  as  well  as  the  anterior.  The  anterior  costal  bones  are  crossed  by 
numerous  ridges  from  side  to  side  obliquely;  the  obliquity  increasing  posteriorly.  On  the  posterior 
bones  they  are  broken  into  vertical  bars,  separated  by  considerable  intervals,  and  of  linear  form.  The 
posterior  costals  reach  a  thickness  of  0.006  m.  and  a  width  of  0.025  m. 

The  pitting  of  the  posterior  part  of  the  carapace  distinguishes  this  species  from  the  P.  cedemius. 

But  one  specimen  obtained. 

Plastomenus?  fractus  Cope. 
Plate  86,  fig.  4. 

Plastomenus  fractus,  CoPE,  Syst.  Cat.  Vert.  Eocene  New  Mexico,  1875,  p.  35;  Append.  LL  of  Wheeler's 

Report  to  Chief  Engineers,  1875,  p.  1016  {o(  separata,  p.  96);  Wheeler's  Surv.  W.  looth   Merid., 

IV,  pt.  ii,  1877,  p.  49,  plate  xxv,  figs.  12-19;  Vert.  Tert.  Form.  West,  1884,  p.  123. — Hay,  Bibliog. 

and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  452. 

** 

The  types  and  all  other  specimens  of  this  species  having  apparently  been  lost,  the  present 

writer  must  content  himself  with  reprinting  Cope's  description  and  one  of  his  figures.     It 

may  be  said,  however,  that  there  is  nothing  about  the  specimens  or  the  description  that  either 

confirms  or  disproves  the  correctness  of  the  reference  of  the  species  to  the  genus  Plastomenus. 

Important  parts  of  the  plastron  are  needed  for  the  settling  of  this  question.     The  species 

comes  from  the  Wasatch  beds  of  New  Mexico;  but  the  exact  locality  was  not  given  by  Cope. 

It  was,  however,  from  the  region  of  the  Gallinas  River. 

Five  individuals  in  a  fragmentary  condition  represent  this  turtle,  and  present  greater  uniformity  of 
character  than  some  of  the  others.  The  sculpture  is  a  honeycomb,  where  the  fossae  are  wider  than  the 
separating  ridges,  [and]  which  is  traversed  at  intervals  of  two  or  three  fossae  by  elevated  lines,  which  are 
transverse  or  oblique  to  the  long  axis  of  the  costal  bones  as  they  are  situated  in  the  carapace.  These 
lines  are  elevated  portions  of  those  separating  the  fossa;,  and  hence  differ  entirely  from  the  smooth,  thick 
welts  of  the  species  of  the  genus  which  follows.  They  are  usually  zigzag  in  their  course,  as  defining  the 
pits,  and  sometimes  inclose  small  pits.  The  vertebral  bones  are  strongly  pitted.  None  of  the  specimens 
indicate  large  size. 

Measurements. 

Meter. 

Width  of  a  vertebral  bone 0.012 

Width  of  a  costal  bone 012 

Thickness  of  same 005 

Interval  between  two  raiseii  lines 007 

Plate  86,  fig.  4,  is  reproduced  from  Cope's  work  of  1877,  cited  above.  The  figs,  w  and  x 
represent  the  outer  and  the  inner  surfaces  of  the  proximal  end  of  a  costal.  Figs,  y  and  2  show 
middle  parts  of  costals.  It  is  greatly  to  be  desired  that  far  better  specimens  of  this  and  other 
Wasatch  species  of  turtles,  so  often  based  on  fragmentary  specimens,  shall  soon  be  found. 


PLASTOMENID^.  473 

Plastomenus  comigatus  Cope. 

Plate  86,  fig.  5. 

Plastomenus  corrugatus.  Cope,  Syst.  Cat.  Vert.  Eocene  New  Mexico,  1875, p.  35;  Append.  LL  of  Wheeler's 
Report  to  Chief  of  Engineers,  1875,  p.  1016  {oi  separata,  p.  96);  Wheeler's  Surv.  W.  lOOth  Merid., 
IV,  pt.  II,  1877,  pp.  48,  50,  plate  XXV,  figs.  20-26;  Vert.  Tert.  Form.  West,  1884,  p.  123. — Hay, 
Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  452. 

Professor  Cope  stated  in  his  monograph  on  the  fossil  vertebrates  of  New  Mexico  that  he 
had  remains  of  6  individuals  which  he  referred  provisionally  to  the  present  species.  Of  these 
he  figured  fragments  of  2.  One  of  these  two  was  represented  by  only  a  portion  of  the  left 
hypoplastron;  and  this  was  regarded  as  the  type  of  the  species.  It  is  represented  by  his  fig.  20, 
which  is  here  reproduced  (plate  86,  fig.  5).  The  other  bones  figured  were  portions  of  costals 
except  the  one  represented  by  his  figure  25.  The  present  writer  is  not  aware  where  these  figured 
specimens  now  are.  They  were  collected  in  the  Wasatch  beds  of  New  Mexico.  The  exact 
locality  was  not  designated,  but  it  was  doubtless  from  the  Gallinas  River  region. 

Of  the  type  bone,  the  hypoplastral,  Cope  makes  the  following  statements: 

This  bone  is  ornamented  with  sharp,  raised,  narrow  ridges,  which  are  straight  or  vermiculate,  and 
which  inosculate  but  little.  The  broken  base  of  the  bridge  is  particularly  stout,  and  the  thickening 
continues  within  the  inguinal  border  to  the  postabdominal  extremity.  The  inguinal  edge  is  thinner,  and 
is  incurved  at  the  postabdominal  gomphosis. 

Measurements. 

Meter. 

Thickness  of  the  hyposternal  at  middle 0.007 

Thickness  of  hyposternal  at  bridge 009 

Seven  ridges  measure 010 

Judging  from  Cope's  figures  of  the  costal  bones,  they  presented  a  very  different  style  of 
ornamentation.  Here  we  find  what  Cope  has  called  a  honeycombed  structure.  There  were 
apparently  abruptly  sunken  pits,  about  5  in  a  line  10  mm.  long;  while  the  intervening  ridges 
were  about  as  wide  as  the  pits  themselves.  Professor  Cope  presented  no  measurements  of  these 
bones,  so  that  we  do  not  know  their  thickness.  Altho  they  are  so  different  in  their  style  of 
ornamentation  from  the  type  plastral  bone  they  appear  to  be  connected  with  it  by  the  bone 
represented  by  Cope's  fig.  25.  Cope  regarded  this  bone  as  a  part  of  the  left  hyoplastron;  but 
a  comparison  of  it  with  the  plastron  of  Plastomenus  thomasi  makes  it  more  probably  the  outer 
end  of  the  right  hyoplastron.    The  fig'ure  ought  to  be  inverted. 

Plastomenus  communis  Cope. 

Plate  86,  figs.  6-8. 

Plastomenus  communis, Cope,  Syst.  Cat.  Vert.  Eocene,  New  Mexico,  1875,  p.  35;  Append.  LL  of  Wheeler's 
Report  to  Chief  of  Engineers,  1875,  p.  1016  (of  separata,  p.  g6);  Wheeler's  Surv.  West  lOOth  Merid., 
IV,  pt.  II,  1877,  pp.  48,  50,  plate  XXV,  figs.  1-3,  .''4;  Vert.  Tert.  Form.  West.  1884,  pp.  123,  126. — 
Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  452. 

That  specimen  which  is  represented  by  fig.  I,  plate  xxv,  of  Cope's  memoir  publisht  in  the 
fourth  volume  of  the  Wheeler  Survey,  must  be  regarded  as  the  type  of  the  present  species. 
This  type  belongs  to  the  U.  S.  National  Museum  and  bears  the  catalog  number  1 132.  It  con- 
sists of  the  distal  ends  of  a  number  of  costal  plates  and  a  portion  of  the  left  hyoplastron.  These 
were  collected  by  Professor  Cope  in  Wasatch  beds  in  New  Mexico,  doubtless  in  the  region 
of  the  Gallinas  River. 

While  the  known  remains  of  this  turtle  indicate  a  distinct  species  and  one  which  may  be 
recognized  when  other  considerable  parts  shall  have  been  discovered,  they  do  not  enable  us 
to  obtain  an  accurate  idea  of  the  animal.  It  must  have  attained  a  considerable  size,  since  one 
of  the  costals  had  a  width  of  44  mm.  It  had  a  thick  and  coarsely  sculptured  shell  (plate  86, 
figs.  6,  7).  There  were  no  rib-ends  protruding  beyond  the  borders  of  the  carapace.  The  form 
of  the  fragment  of  the  hyoplastron  (plate  86,  fig.  8)  present  indicates  pretty  certainly  that  the 
species  belongs  to  the  genus  Plastomenus. 


474  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

The  free  borders  of"  the  costals  are  thick  and  obtuse,  resembling  the  edge  of  one's  little 
finger  (plate  86,  fig.  6b).  That  costal  which  forms  the  lower  part  of  fig.  6  here  presented  has  a 
thickness  of  12  mm.  The  upper  surface  of  the  costals  is  ornamented  with  pits,  of  which  there 
are  about  4  in  a  line  10  mm.  long,  being  somewhat  larger  than  stated  by  Cope.  On  what  are 
evidently  posterior  costals  there  are  conspicuous  welts,  which,  at  the  distal  ends  of  the  costals, 
run  parallel  with  the  sutural  borders.  The  pits  are  in  rows  parallel  with  the  free  borders  of 
the  costals. 

The  portion  of  the  hypoplastron  belonging  to  the  type  agrees  closely  in  form  with  that  of 
P.  thomast.  Cope's  figure  is  reproduced  on  page  86,  fig.  8.  The  lower  border  joined  the  hypo- 
plastron. The  lower  half  of  the  border  on  the  left  joined  the  hyoplastron  of  the  opposite  side. 
The  oblique  border  above  this  formed  a  part  of  the  boundary  of  a  fontanel.  The  lower  sur- 
face, as  seen,  was  sculptured  with  pits,  arranged  in  rows  parallel  with  the  mesial  border.  These 
pits  are  smaller  than  those  of  the  carapace,  there  being  about  6  or  7  of  them  in  a  10  mm.  line. 

In  his  description  given  in  the  Wheeler  Survey  Cope  includes  some  fragments  in  this 
species  that  he  afterwards  (Vert.  Tert.  Form.  West,  p.  125)  referred  to  P.  molopinus,  the  type 
of  which  came  from  the  Bridger  beds.  While  these  specimens  quite  certainly  do  not  belong 
to  P.  communts,  it  is  doubtful  if  they  belong  to  P.  molopinus.  It  is  to  be  noted  that  in  the 
text  of  the  Wheeler  Survey  Cope  refers  to  these  specimens  as  representing  a  "var.  ii,"  but  in 
the  explanation  of  his  plate  xxv  he  speaks  of  them  as  "var.  i." 

Plastomenus  thomasi  Cope. 

Text-figs.  633-637. 

Trionyx  tliomasit,  CoPE,  1872,  Proc.  Amer.  Philos.  Soc,  xil,  p.  462. 

Plastomenus  thomasii,  Cope,  Proc.  Acad.  Nat.  Sci.  Phila.  1873,  p.  278  (name  only);    6th  Ann.  Report 

U.  S.  Geol.  Surv.  Terrs.,  1872  (1873),  p.  618;    Ann.  Report  Chief  Engineers,  1875,  Append,  ll,  p. 

1016  (of  reprint,  p.  g6.) — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  453. 
Plastomenus  multifoveatus,  CoPE,  1 873,  Proc.  Acad.  Nat.  Sci.  Phila.  p.  278  (name  only);     6th  Ann. 

Report  U.  S.  Geol.  Surv.  Terrs.,  1872  (1873),  p.  619;  Vert.  Tert.  Form.  West,  1884,  pp.  123,  125, 

plate  xviii,  figs.  2-8. 

The  original  description  of  the  present  species  was  extremely  brief;  and  we  could  only 
with  difficulty  know  that  it  applied  to  the  species,  had  not  Professor  Cope  quoted  it  in  subse- 
quent and  more  detailed  descriptions.  Only  portions  of  the  carapace  were  mentioned.  What 
appears  to  be  the  next  reference  to  the  species,  that  in  the  Proceedings  of  the  Philadelphia 
Academy,  was  accompanied  by  no  characters  to  distinguish  it  from  related  species.  With  it 
was  mentioned  another  species  called  P.  multifoveatus.  It  was  in  this  communication  that  the 
genus  Plastomenus  was  proposed,  the  characters  of  which  were  based  on  both  carapace  and 
plastron.  In  Hayden's  Report  for  1872,  as  cited  above,  there  appear  descriptions  of  both  P. 
thomasi  and  P.  multifoveatus.  With  the  former  were  briefly  described  some  plastral  bones. 
In  the  fourth  volume  of  the  Wheeler  Survey,  Professor  Cope  described  New  Mexican  specimens 
which  he  regarded  as  belonging  to  P.  multifoveatus.  To  this  species  he  now  refers  the 
specimens  which  he  had  originally  called  /-•.  thomasi,  while  the  latter  name  is  restricted  to 
plastral  bones  which  he  states  were  more  like  those  of  Trionyx.  In  the  Vertebrata  of  the 
Tertiary  Formation  of  the  West,  1884,  he  writes  as  follows  under  P.  multifoveatus: 

When  I  stated  there  [Report  Geol.  Surv.  1872]  that  P.  thomasii  is  the  type  of  the  genus  Plastomenus 
I  referred  to  these  specimens;  it  is  therefore  to  be  observed  that  the  type  of  the  genus  is  really  the  P. 
multifoveatus.    The  true  P.  thomasii  was  founded  on  sternal  bones  perhaps  of  a  small  species  of  Trionyx . 

Regarding  this  statement  the  following  may  be  said:  (i)  No  plastral  bones  were  men- 
tioned in  the  original  description  of  P.  thomasi.  (2)  The  description  of  P.  thomasi  found  in 
the  Hayden  Survey  report  of  1872  was  taken  bodily  into  the  description  of  1884.  (3)  We 
know  of  no  description  of  the  plastral  bones  on  which  Cope  says  that  P.  thomasi  \V3s  founded. 
In  view  of  these  facts  we  must  say  that  whatever  Cope  had  in  mind,  he  did  not,  according  to 
the  recognized  rules  of  nomenclature,  attach  the  name  P.  thomast  to  the  Trionyx-like  plastral 
bones,  but  did  attach  it  to  those  specimens  which  he  afterward  called  P.  multifoveatus.  The 
latter  name  therefore  becomes  a  synonym  of  the  former. 


PLASTOMENID^. 


475 


The  bones  of  the  plastron  which  Professor  Cope  was  disposed  to  take  as  the  type  of  P. 

thomasi  are  now  in  the  American  Museum  of  Natural  History,  and  are  described  under 

Platypeltis  serialis. 

Those  specimens  which  Professor  Cope  figured  in  his  great  work  of  1884  under  the  name 

P.  multifoveatus  must  be  regardetl  as  the  type  of  the  present  species.     Of  these  specimens 

that  which  furnisht  fig.  6  of  plate  xviii  is 
now  in  the  American  Museum  of  Natural 
History.  The  others  are  in  the  U.  S. 
National  Museum  at  Washington.  Of 
these  figures,  2  and  5  represent  the  distal 
ends  of  2  costals;  fig.  3,  the  outer  end  of 
the  right  hyoplastron;  fig.  4  is  the  left 
hypoplastron;  and  fig.  7,  the  right  hypo- 
plastron.  Figs.  2  and  5  seem  to  indicate 
that  the  sculpture  is  irregular,  but  in  the 
text  Cope  states  that  the  ribs  intervening 
between  the  pits  tend  to  connect  into  ridges 
running  diagonally  across  the  costal  bones. 
These  specimens  were  obtained  on  Cotton- 
wood Creek. 

The  American  Museum  party  of  1903 
operating  in  the  Badlands  of  the  Bridget 
Basin  discovered  a  nearly  complete  shell 
which  is  identified  as  belonging  to  Cope's 
P.  thomasi.  It  was  found  at  Grizzly 
Buttes,  and  the  catalog  number  of  the 
specimen  is  6018.  The  carapace  lacks  only 
unimportant  fragments.     From  the  plas- 


FlG.  631. — Plastomenus  thomasi.     Carapace. 
No.  6018  A.  M.  N.  H. 


XJ. 


tron  there  are  missing  the  entoplastron,  the  epiplastra,  the  median  end  of  the  right  hyo- 
plastron, and  the  right  xiphiplastron. 

The  carapace  (fig.  631)  has  a  length  of  218  mm.  and  a  breadth  of  210  mm.  The  upper 
surface  was  evidently  moderately  convex  during  life.  The  nuchal  bone  extends  from  side  to 
side  a  distance  of  97  mm.  and  from  front  to  back  30  mm.    There  are  present  a  preneural  and 

six  neurals.  It  is  probable  that  there  was  a  small  seventh 
neural  in  a  notch  between  the  costals  of  the  seventh  pair. 
The  table  shows  the  dimensions  of  these  elements. 

The  costals  of  the  eighth  pair  meet  along  the  midline 
48  mm.  and  each  measures  48  mm.  along  the  free  border. 
The  outer  ends  of  the  ribs  extend  but  little  beyond  the  bor- 
der of  the  disk.  The  outer  ends  of  the  costals  are  about  7 
mm.  thick;  and  between  the  upper  and  lower  layers  of  the 
bone  there  is  a  channel  running  around  most  of  the  border. 
On  each  side  of  the  upper  surface  there  are  seen  about 
8  low  and  broad  welts;  2  or  3  of  these  extend  on  the  nuchal. 
The  nuchal  and  the  outer  ends  of  the  costals  are  ornamented  with  shallow  pits.  These  are 
mostly  arranged  in  rows  parallel  with  the  border  of  the  disk.  A  line  10  mm.  long  extends 
across  4,  sometimes  5  pits.  On  the  neurals  and  the  proximal  ends  of  the  costals  the  pits  are 
nearly  obsolete. 

The  form  of  the  plastron  and  the  proportions  of  its  diflFerent  parts  may  be  seen  in  fig.  632. 
The  width  of  the  plastron  between  the  ends  of  the  hyohypoplastral  suture  is  210  mm.;  the 
length  along  the  midline,  excluding  the  missing  elements,  is  135  mm.  The  bones  of  the 
opposite  sides  are  joined  by  jagged  sutures.  The  hyohypoplastral  suture  of  each  side  makes 
an  angle  of  about  75°  with  the  median  longitudinal  suture.  The  greatest  width  of  the  hyo- 
plastron is  47  mm.;  the  width  of  the  midline,  25  mm.  The  width  of  the  hypoplastron  at  the 
midline  is  49  mm.;  of  the  xiphiplastron,  60  mm.  The  width  of  the  hinder  lobe,  at  its  base,  is 
100  mm.;    its  length  is  85  mm.     The  thickness  of  the  hyoplastron  at  the  midline  is  5  mm.; 


Element.              Length. 

Width. 

Preneural 15 

Neural  i 19 

Neural  2 20 

Neural  3 19 

Neural  4 18 

j  Neural  5 17.5 

Neural  6 14 

g 

476 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


of  the  hyoplastron,  7  mm.;  of  the  xiphiplastron,  5  mm.  In  front  of  the  hyoplastra  there  was 
probably  a  small  fontanel,  indicated  by  a  notch  in  each  bone.  The  notch  farther  from  the 
midline  received  one  end  of  the  entoplastron.  The  lower  surface  of  all  the  plastral  bones  is 
covered  with  shallow  pits.  Most  of  these  are  in  rows  parallel  with  the  free  borders  of  the 
plastron.  There  are  four,  sometimes  five,  sometimes  only  three  pits  in  a  line  10  mm.  long. 
Mr.  Walter  Granger,  in  1903,  discovered  at  Grizzly  Buttes  the  skull  and  the  outer  end  of 
the  left  hypoplastron  of  a  trionychid  which  proves  to  belong  to  the  present  species.  Judging 
from  the  portion  of  hypoplastron,  the  individual  was  about  half-grown.  The  specific  identity 
of  this  bone  with  that  of  the  larger  individuals  is  furnisht  by  a  hypoplastron  belonging  to  tlie 
Cope  collection,  No.  1030  of  the  American  Museum  of  Natural  History.  Of  the  skull  (figs. 
633-635)  practically  all  portions  are  represented;  but  the  palatal  region  has  not  been  cleaned 
of  the  matrix.  The  premaxillary  bone  is  wanting  and  the  occipital  condyle  is  broken  away, 
but  the  length  of  the  skull  from  the  extremity  of  the  one  of  these  bones  to  the  other  has  been 
close  to  50  mm.  From  the  snout  to  the  end  of  the  supraoccipital  process  has  been  57  mm. 
The  head  is  narrow,  24.5  mm.  wide,  slightly  less  than  one-half  the  length  to  the  occipital 
condyle.     The  snout  is  long  and  narrow.     The  upper  surface  of  the  skull  forms  a  regular 


634- 
Figs.  632-6^5. — PJostomenus  thomasi.     Plastron  and  skull. 


633- 


63Z.  Plastron.    X^    No.  6oi8  A.  M.  N.  H. 
634.  Skull,  side  view.    Xi.    No.  6015  A.M.  N.H. 


633.  Skull,  upper  view.    Xi.    No.  6015  A.  M.  N.  H. 
635.  Lower  jaw,  from  below.    Xi.     No.  6015  A.M.N.  H. 


curve  from  the  snout  to  the  end  of  the  supraoccipital  process.  The  orbit  has  an  antero-posterior 
diameter  of  10  mm.,  and  the  space  between  this  and  the  nostril  was  the  same.  No  postfrontal 
bone  has  been  discerned.  The  postorbital  process  of  the  jugal  reaches  the  parietal  and  this 
bone  enters  into  the  formation  of  the  orbit,  a  very  unusual  arrangement.  In  PlatypelUs 
spintfera  the  postfrontal  bone  is  small,  but  it  excludes  the  parietal  from  the  orbit.  In  Plasto- 
menus  thomasi  the  interorbital  space  has  a  width  of  4  mm.  The  squamosal  process  was 
formed  as  in  Platypeltis.  The  lower  jaw  (fig.  635)  is  narrowed  in  front;  the  symphysis  is  14 
mm.  long. 

The  respects  in  which  this  species  differs  from  P.  visenJus,  referred  in  a  former  publication 
to  P.  thomast,  will  be  given  under  P.  vtsendus. 

Plastomenus  visendus  sp.  nov. 
Plate  87,  figs.  I,  2;  teit-figs,  636,  637. 
Plastomenus  thomasii,  Hay,  Amer.  Geologist,  xxxv,  1906,  p.  334,  figure. 

Among  the  materials  included  in  the  Cope  collection  now  in  the  American  Museum  of 
Natural  History  there  was  found  a  cigar-box  of  fragments  which  had  been  collected  in  the 
Bridget  deposits  of  the  Rattlesnake  Hills,  Wyoming,  in  1895,  by  Mr.  Stanley  Stuart.  On 
being  fitted  together  these  fragments  furnisht  a  nearly  complete  carapace  and  plastron  of  a 


PLASTOMENID^. 


477 


species  of  Plastomenus.  It  was  originally  supposed  that  this  was  Cope's  P.  thomasi,  but  the 
fortunate  discovery  of  a  specimen  of  the  latter  at  Grizzly  Buttes,  near  the  type  locality,  shows 
that  the  specimen  from  the  Rattlesnake  Hills  belongs  to  a  distinct  and  hitherto  undescribed 
species.     The  catalog  number  of  the  specimen  is  1895. 

In  form  this  species  is  broadly  oval,  with  the  broadest  portion  somewhat  in  front  of  the 
middle  of  the  carapace.  The  latter  appears  to  have  been  only  moderately  archt.  The  total 
length  of  the  carapace  (plate  87,  fig.  i;  text-fig.  636)  is  207  mm.  along  the  midline.  The 
greatest  width  is  204  mm.  There  were  no  fontanels  in  the  carapace,  and  the  ribs  extended 
beyond  the  disk  probably  nowhere  more  than  about  12  mm.  There  is  no  evidence  that  there 
were  any  peripheral  bones.  The  nuchal  is  firmly  united  with  the  first  pair  of  costals.  Only  a 
fragment  of  the  preneural  is  preserved.  There  are  present  remains  of  4  neurals.  Of  the  first 
there  is  only  a  fragment.  The  fifth  and  sixth  neurals  are  missing.  The  costals  of  the  seventh 
and  eighth  pairs  meet  in  the  midline  for  their  whole  breadth;    hence  corresponding  neurals 


YlGS.  636  AND  637. — Plnstomenus 
visenJus.     X  4. 


636.  Carapace. 


637.  Plastron. 


were  not  developt.  The  nuchal  has  a  lateral  extent  of  90  mm. ;  and  a  fore-and-aft  extent  of 
20  mm.  Its  outer  ends  neither  overlap  nor  underlap  the  anterior  border  of  the  first  costals. 
These  costals  are  somewhat  narrower  at  their  distal  ends  than  at  the  proximal.  The  other 
costals,  except  the  seventh,  are  wider  at  the  outer  ends  than  proximally.  The  seventh  costals 
are  much  wider  along  the  midline  than  any  of  the  others,  and  form  a  large  part  of  the  rear  of 
the  shell.  They  extend  along  the  midline  a  distance  of  50  mm.,  and  laterally  from  the  midline 
a  distance  of  75  mm.  The  edges  of  the  carapace  are  rounded  or  cut  off  rather  abruptly.  The 
thickness  of  the  costals  at  the  free  edges  is  about  5  mm.  The  only  neural  which  is  complete 
is  the  third.    It  has  a  length  of  18  mm.  and  a  width  of  12  mm.  posteriorly. 

The  ornamentation  consists  of  a  number  of  longitudinal  welts  and  of  numerous  pits.  Of 
the  welts  there  are  about  10  on  each  side.  These  resemble  a  series  of  waves,  those  near  the 
midline  being  somewhat  nearer  together  than  those  near  the  borders  of  the  carapace.  On  the 
hindermost  costals  the  welts  are  sharper  and  somewhat  broken  up  into  elongated  nodules. 
On  the  nuchal  and  costals  of  the  first  pair  the  welts  are  obsolete.  The  pits  are  rather  shallow 
and  are  separated  by  ridges  which  are  rounded  or  flat  on  their  summits.  There  are  5  or  6  of 
the  pits  in  a  line  10  mm.  long.  They  are  less  distinct  on  the  neurals  and  the  proximal  ends  of 
the  costals.  On  the  outer  halves  of  most  of  the  costals  the  pits  are  arranged  to  a  great  extent 
in  rows,  parallel  with  the  axis  of  the  animal  or  with  the  adjacent  free  border  of  the  carapace. 

Of  the  plastron  (plate  87,  fig.  2;  text-fig.  637)  the  entoplastron,  both  epiplastra,  and  a 
small  portion  of  the  left  hypoplastron  are  missing.    The  parts  present  are  shown  on  the  plate 


478  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

cited.  As  will  be  observed,  there  was  a  median  fontanel  partly  inclosed  by  the  hyoplastrals. 
Behind  this  the  elements  of  the  plastron  met  along  the  midline  to  the  hinder  extremity  of  the 
xiphiplastrals,  just  as  in  Chrysemys.  While  the  hypoplastra  join  the  xiphiplastra  by  digitations 
near  the  outer  borders  of  these  bones,  these  digitations  are  more  feeble  than  in  most  trionychids. 
The  digitations  reaching  from  one  xiphiplastron  to  the  other  are  hardly  discernible.  At  the 
outer  ends  of  the  hyoplastron  and  of  the  hypoplastron  the  space  between  the  outwardly  pro- 
jecting processes  is  more  nearly  filled  up  than  usual  in  trionychids.  Everywhere  the  distinction 
between  the  bone  of  the  "callosities"  and  that  forming  the  framework  of  the  plastron  is  less 
obvious  than  in  ordinary  trionychids. 

The  length  of  the  plastron,  from  the  line  joining  the  antero-interior  angles  of  the  hyoplastra 
to  the  hinder  border  of  the  xiphiplastra,  is  133  mm.  Of  this  distance  the  union  of  the  hyo- 
plastra occupies  about  10  mm.,  that  of  the  hypoplastra  45  mm.,  that  of  the  xiphiplastra  92  mm. 
The  greatest  width  of  the  hyoplastron  is  33  mm.  From  the  extremity  of  one  postero-external 
process  of  the  hypoplastron  to  the  other  is  210  mm.  The  width  of  the  posterior  lobe  of  the 
plastron  at  its  base  is  108  mm.  The  width  of  the  bridge  is  48  mm.,  of  which  the  hyoplastron 
occupies  33  mm. 

On  the  plastron  there  are  no  welts,  such  as  appear  on  the  carapace.  The  pits  are  not  to  be 
distinguisht  from  those  of  the  upper  part  of  the  shell.  They  are  largest  and  deepest  on  the 
outer  end  of  each  hypoplastron.  They  are  often  arranged  in  rows  which  are  parallel  with  the 
nearest  border  of  the  bone.     These  rows  of  pits  are  most  conspicuous  on  the  hyoplastron. 

This  species  differs  from  P.  thomasi  in  several  particulars.  Both  the  nuchal  and  the  hyo- 
plastron have  the  fore-and-aft  width  considerably  less  than  in  P.  thomasi.  The  hinder  border 
of  the  bridge  portion  of  the  hypoplastron  makes  a  larger  angle  with  the  midline  than  in  P. 
thomasi,  and  the  pits  of  the  median  portions  of  the  bones  of  the  plastron  are  larger.  Espe- 
cially, the  costals  of  the  eighth  pair  extend  farther  along  the  hinder  border  of  the  carapace  than 
they  do  in  P.  thomasi.  The  front  of  the  carapace  of  the  latter  appears  to  be  more  pointed  than 
that  of  the  present  species. 

Plastomenus  tantillus  sp.  nov. 
Figs.  638,  639. 

The  present  specific  name  is  applied  to  a  specimen  which  was  found  by  the  writer  in  the 
Bridger  beds,  near  the  mouth  of  Cottonwood  Creek,  Wyoming,  in  the  year  1903.  The  level 
is  that  designated  as  B.  The  individual  is  a  small  one,  with  thin  and  delicate  bones,  and  it  was 
probably  a  young  animal.  It  has  been  greatly  flattened  by  pressure,  and  to  this  is  due  the 
spreading  apart  of  some  of  the  costals  at  their  distal  ends.  There  are  present  nearly  the  com- 
plete carapace  and  the  greater  portion  of  the  plastron.  The  specimen  bears  the  American 
Museum's  catalog  number  5980. 

The  outline  of  the  carapace  (fig.  638)  is  rather  elongated.  There  was  probably  a  slight 
excavation  in  the  anterior  border  of  the  nuchal.  The  hinder  border  is  rounded.  The  length 
of  the  carapace  is  105  mm.;  the  width,  excluding  the  extension  of  the  free  ends  of  the  ribs,  is 
90  mm.  The  rib-ends  projected  beyond  the  disk  an  undetermined  distance.  The  nuchal  has 
a  lateral  extent  of  46  mm.;  a  fore-and-aft  extent  of  13  mm.  There  is  a  wide  band  in  front  and 
at  the  ends  which  is  devoid  of  the  enameled  and  sculptured  band.  This  bone  was  quite  cer- 
tainly in  contact  with  a  preneural,  but  the  latter  is  not  preserved.  There  are  seven  neurals, 
but  the  hindermost  one  is  very  small,  having  a  length  of  only  2  mm.  The  other  neurals  are 
comparatively  broad.  Most  of  them  have  the  usual  hexagonal  form  seen  in  the  Trionychoidea; 
but  the  first  is  4-sided.  The  third  has  a  length  of  a  little  more  than  10  mm.,  and  a  width  of 
9  mm.    Both  in  front  of  and  behind  the  third,  the  others  are  slightly  smaller. 

There  are  8  pairs  of  costals.  They  are  thin,  the  bone  having  a  thickness  of  only  1.5  mm. 
at  the  sutural  margins  and  but  little  more  than  2  mm.  where  thickest.  The  rib  of  each  costal 
occupies  about  one-half  of  the  whole  width  of  the  plate.  The  first  costal  has  a  width  of  17  mm. 
Those  of  the  seventh  pair  join  in  the  midline.  Those  of  the  eighth  pair  join  for  their  whole 
length  along  the  midline,  a  distance  of  16  mm. 

The  ornamentation  of  the  carapace  consists  of  narrow  longitudinal  welts,  shallow  pits, 
and  punctae.  There  are  5  or  6  low  welts  on  each  side  of  the  carapace.  The  pits  are  distinct 
ever}'where,  except  on  the  neurals  and  the  proximal  ends  of  most  of  the  costals,  where  they  are 
replaced  by  the  punctas.    Of  the  pits  there  are  usually  8  in  a  line  10  mm.  long. 


PLASTOMENID^. 


479 


The  plastron  (fig.  639)  resembles  in  general  that  of  P.  thomasi,  but  the  bones  have  not 
joined  so  closely  along  the  midline,  a  condition  indicative  of  youth.  The  bones  average  about 
2  mm.  in  thickness.  At  the  inguinal  notch  the  hypoplastron  is  4  mm.  thick.  On  a  line 
joining  the  axillary  and  inguinal  notches,  the  hypoplastron  is  nearly  as  wide  as  the  hyoplas- 
tron;  but  this  is  quite  certainly  a  feature  due  to  immaturity.  The  same  difference  may  be 
noted  between  the  young  and  the  adult  ot  Plafypeltts  spmifera. 

The  plastral  bones  are  covered  with  a  network  of  ridges  inclosing  shallow  pits,  except  on 
the  processes.  The  pits  are  like  those  of  the  carapace  in  size  and  distance  apart.  They  are, 
to  a  great  extent,  arranged  in  rows  parallel  with  the  nearest  border  of  the  bone.  This  is  most 
evident  on  the  xiphiplastra. 

This  individual  differs  in  various  respects  from  the  specimens  which  are  referred  to  P. 
thomasi;   but  many  of  these  differences  may  be  due  to  the  immature  condition  of  the  animal. 


KiGS.  638  AND  639. — Plastomenus  tantillus.     Carapace  and  plastron  of  type.     X  I- 

638.  Carapace,    c.p.  i,  c.p.  i,  first  and  eighth  costals;    n.  i,  n.  6,  first  and 

sixth  neurals;    nu.  p.,  nuchal  plate;    pren,  preneural. 

639.  Plastron,     hyo,  hyoplastron;    hypo,  hypoplastron;  xiph,  xiphiplastron. 

The  carapace  would  probably  become  somewhat  broader  with  age,  as  the  space  between  the 
free  ends  of  the  ribs  became  filled  up.  The  anterior  costals  are  relatively  broader,  fore  and 
aft,  than  in  P.  thomasi.  The  eighth  costals  meet  along  the  midline  a  distance  which  is  con- 
tained in  the  entire  length  of  the  carapace  6.5  times;  whereas,  in  the  adult  specimens  of  P. 
thomasi,  the  length  of  their  union  is  contained  in  the  entire  length  only  4.5  times.  In  the 
latter  species  the  hinder  border  is  somewhat  excavated;  in  P.  tantillus  it  is  convex.  The 
sculpture  of  P.  thomasi  is  considerably  coarser  than  that  of  the  species  here  described;  and 
it  is  believed  by  the  writer  that  the  coarseness  of  the  sculpture  of  Trionychoidea  changes 
little,  if  at  all,  with  increase  in  size  of  the  individual. 

Plastomenus  oedemius  Cope. 

Figs.  640,  641 . 

Anostira  cedemia,  Cope,  Pala;ont.  Bull.  No.  1,  July  2q,  1872,  p.  461;   Proc.  Amer.  Philos.  Soc.  xn,  1873, 

p.  461. 
Plastomenus  wdemius,  CoPE,  6th  Ann.  Kept.  U.  S.  Geol.  Surv.  Terrs.,  1873,  p.  619;    Proc.  Acad.  Nat. 

Sci.   Phila.   1873,  p.  279;   Wheeler's  Surv.  West.  looth  Merid.,  iv,  1877,  p.  48;   Vert.  Ten.  Form. 

West,  1884,  pp.  123,  126,  plate  xviii,  figs.  15-17.— Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902, 

p.  453;    Amer.  Geologist,  xxxv,   1905,  p.  334. 

The  type  specimens  of  this  species,  figured  by  Cope  as  cited  above,  are  now  a  part  of  the 
Cope  collection  in  the  American  Museum  of  Natural  History.  With  these  are  other  specimens 
which  were  collected  by  Cope,  but  they  are  fragmentary  and  throw  little  light  on  the  structure 


480 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


of  the  species.  Some  of  the  specimens  mentioned  by  that  author  are  either  not  present  or  have 
not  been  recognized.  They  had  all  been  collected  in  the  Bridget  beds  of  Wyoming.  The  type 
came  from  Cottonwood  Creek  and  therefore  from  level  B,  and  has  the  American  Museum's 
number  3937, 

In  the  year  1903  the  American  Museum  of  Natural  History  sent  a  party  into  the  Eocene 
Badlands  in  the  region  of  Fort  Bridger,  Wyoming.  Among  the  materials  collected  by  this 
party  is  a  nearly  complete  carapace  and  a  fragmentary  plastron,  which  are  believed  to  belong  to 
the  above  species.  These  parts  are  represented  by  figs.  640  and  641.  The  specimen  bears  the 
catalog  number  5978. 

In  form  the  carapace  is  oval,  or  elliptical,  narrowed  in  front,  rounded  behind.  It  is  con- 
siderably archt,  the  midline  rising  to  a  height  of  73  mm.  above  the  borders.  The  length  is 
310  mm.;  the  width,  270  mm.  The  carapace  (fig.  640)  consists  of  a  nuchal,  8  pairs  of  costals, 
a  preneural,  and  6  neurals.    The  nuchal  has  a  length  of  145  mm.  and  a  fore-and-aft  width  of 


641. 


Figs.  640  and  641. — Plastomenus  cedemius.     Carapace  and  plastron. 
Xi     No.  5978  A.  M.  N.  H. 


640.  Carapace. 


641.  Plastron. 


38  mm.  along  the  midline.  Its  hinder  border  is  somewhat  excavated  for  the  preneural.  The 
costals  widen  toward  their  distal  ends.  The  free  border  of  each  is  beveled.  The  free  ends  of 
the  ribs  are  very  short.  The  thickness  of  the  costals  is  about  5  mm.  Those  of  the  sixth  pair 
inclose  between  their  proximal  ends  the  sixth  neural;  but  behind  this  they  join  in  the  midline. 
The  costals  of  the  seventh  and  eighth  pairs  also  meet  in  the  midline,  the  former  for  a  distance 
of  20  mm.,  the  latter  for  a  distance  of  65  mm. 

The  preneural  is  pentagonal,  24  mm.  long,  and  of  about  the  same  width.  The  first  neural 
is  pentagonal,  25  mm.  long  and  19  mm.  wide.  The  right  postero-lateral  side  is  very  short,  and 
articulates  with  the  second  right  costal.  The  third  neural  is  four-sided,  34mm.  long  and  i6mm. 
wide.  The  next  3  neurals  are  hexagonal,  with  the  narrow  end  forward.  The  fifth  is  13  mm. 
wide.    The  last  neural  is  small,  15  mm.  long  and  6  mm.  wide. 

The  sculpture  of  the  surface  consists  of  longitudinal  ridges,  or  welts,  and  shallow  pits. 
Neither  the  welts  nor  the  pits  are  conspicuous.  The  welts  are  obsolete  on  the  anterior  half  of 
the  carapace,  most  distinct  posteriorly.  Running  longitudinally  as  they  do,  they  cross  the  cos- 
tals of  the  middle  of  the  carapace  at  right  angles.  Posteriorly  they  cross  the  costals  obliquely. 
A  close  examination  of  the  welts  shows  that  they  resemble  those  of  the  type  of  the  species.  On 
the  last  costal  they  run  in  the  same  direction  and  become  resolved  into  low  tubercles,  but  these 
are  not  so  swollen  as  in  the  type. 


plastomenidjS:.  481 

The  pits  are  shallow  and  in  many  portions  of  the  carapace,  especially  near  the  midline  and 
on  the  rear,  they  are  obsolete.  Many  of  them  form  what  Cope  has  designated  punctae.  They 
cover  the  nuchal,  the  outer  halves  of  the  anterior  costals,  and  distal  thirds  of  hinder  costals. 

A  considerable  portion  of  the  plastron  (fig.  641)  is  preserved,  but  it  is  fragmentary  and, 
in  many  cases,  there  is  contact  between  the  fragments  present.  It  is  believed,  however, 
that  the  restoration  presented  by  fig.  641  is  not  far  from  correct.  The  specimen  has  furnisht 
the  entoplastron,  a  part  not  hitherto  known  in  the  genus. 

The  length  of  the  plastron,  from  the  front  of  the  entoplastron  to  the  hinder  end  of  the 
xiphiplastrals,  is  about  245  mm.;  the  width  about  275  mm.  Evidently  there  were  no  fontanels 
in  the  midline,  except  a  short  and  wide  one  just  behind  the  entoplastron.  The  latter  bone  is 
more  like  that  o{  Cyclanorhis  senegalensis,  as  figured  by  Siebenrock  (Sitzber.  Akad.  Wissensch. 
Wien,  xci,  1902,  p.  34),  than  like  that  of  any  other  living  species.  The  lateral  branches  of  the 
bone  made  an  obtuse  angle  with  each  other.  The  original  bones  are  covered  with  a  thick 
callosity  and  this  has  filled  up  the  angle  between  them.  The  bone  measures  38  mm.  on  the 
midline,  and  is  from  6  mm.  to  8  mm.  thick. 

The  hyoplastra  meet  along  the  midline  a  distance  of  50  mm.;  the  hypoplastra,  a  distance 
of  about  75  mm.  The  hinder  sutural  border  of  the  hypoplastron  is  not  present,  and  the  xiphi- 
plastron  ought  possibly  to  have  been  removed  somewhat  further  backward,  but  certainly  not 
much  further.  The  hyoplastra  were  flat  for  a  distance  of  about  60  mm.  on  each  side  of  the 
midline;  then  they  have  sloped  upward  and  outward.  Where  the  slope  begins,  the  bone  is 
about  12  mm.  thick.  The  outer  ends  are  considerably  thinner.  The  outer  end  of  the  hypo- 
plastron is  13  mm.  thick,  and  terminates  in  2  processes.     The  inguinal  notch  was  abrupt. 

The  hinder  portion  of  the  hypoplastron  which  is  shown  in  the  figure  preserves  the  sutural 
border  which  joined  the  bone  of  the  opposite  side.  It  shows  therefore  the  width  of  that  part  of 
the  hinder  lobe.  This  was  close  to  1 25  mm.  The  hypoplastron  had  a  thickness  of  about  1 2  mm . 
at  the  inner  border,  but  thinned  toward  the  free  border. 

The  median  and  anterior  sutural  borders  of  the  xiphiplastron  have  not  been  preserved, 
but  the  bone,  both  mesially  and  anteriorly,  evidently  approaches  these  sutures  closely.  The 
outer,  or  free,  border  of  the  hinder  lobe  was  quite  certainly  concave  at  the  hypoxiphiplastral 
suture  and  convex  both  in  front  and  behind  it.  The  hinder  half  of  the  xiphiplastron  has  a 
thickness  near  the  mesial  border  of  6  mm.;  near  the  free  border,  4  mm.  The  hinder  border  of 
the  lobe  was  probably  slightly  excavated. 

The  whole  lower  surface  of  the  plastron,  except  possibly  the  epiplastra,  which  are  not 
known,  is  sculptured  into  a  network  of  ridges,  which  inclose  pits  of  varying  sizes  and  depths. 
On  the  entoplastron  the  pits  are  irregularly  arranged  and  shallow,  and  there  are  5  or  6  of  them 
in  a  line  10  mm.  long.  The  median  half  of  the  hyoplastron  is  similarly  ornamented,  altho 
toward  the  suture  with  the  hypoplastron  the  pits  become  obsolete.  The  outer  extremity  of 
the  hypoplastron  is  furnisht  with  large  pits,  three  or  four  in  a  line  of  10  mm.  That  portion  of 
this  bone  which  enters  into  the  hinder  lobe  has  the  pits  arranged  in  regular  rows  which  run 
parallel  with  the  free  border  of  the  lobe.  Four  rows  of  pits  occupy  a  distance  of  10  mm.  The 
xiphiplastra  are  similarly  ornamented,  but  the  pits  become  somewhat  smaller  posteriorly  and 
the  rows  less  regular.  This  specimen  was  collected  in  the  western  portion  of  Grizzly  Buttes. 
Cope  states  that  two  of  his  specimens  came  from  Cottonwood  Creek. 

Plastomenus  molopinus  Cope. 
Plate  85,  fig.  3;    text-fig.  642. 

Trionyx,  Leidy,  Contrib.  Ext.  Fauna  West.  Terrs.,  1873,  p.  180,  plate  xvi,  figs,  i,  2. 

Anostira  molopinus,  CoPE,  Palaeont.  Bull.  No.  I,  July  29,  187],  p.  461;    Proc.  Amer.  Philos.  Soc,  xil, 

1873,  p.  461. 
Plastomenus  molopinus,  CoPE,  6th  Ann.  Rapt.  U.  S.  Geol.  Surv.  Terrs.,  1873,  P- ^  ^°'  P""*"^-  Acad.  Nat. 

Sci.    Phila.    1873,  p.  279;  Vert.  Tert.  Form.  West,   1884,  pp.  123,   125,  plate  xviii,  figs.   9-14. — 

Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  452. 
Plastomenus  communis  var.  ii.  Cope,  Wheeler's  Surv.  W.  looth  Merid.,  1877,  p.  50,  pi.  xxv,  figs.  5,  6. 

Professor  Cope  stated  that  he  possest  remains  of  8  individuals  of  this  species  from  the 
Bridger  beds  of  Wyoming.  The  specimens  figured  by  him  in  his  Vertebrata  of  the  Tertiary 
Formations  of  the  West  belonged  to  one  individual,  and  consist  wholly  of  fragmentary  costal 
plates.    They  are  now  in  the  American  Museum  of  Natural  History  and  have  the  number  6072. 

31 


482 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


Cope  did  not  clearly  distinguish  this  species  from  P.  cedemtus.  One  last  costal  is  indeed 
mentioned  as  being  crost  by  longitudinal  ridges;  and  he  states  that  if  these  had  been  broken 
up  into  tubercles  he  would  have  referred  the  specimen  to  P.  wdetnius. 

In  the  collection  of  turtles  secured  by  the  American  Museum  expedition  of  1903  there  are 

2  specimens  which  the  writer  refers  to  P.  molopinns.  These  were  obtained  at  Grizzly  Buttes, 
from  the  level  known  as  B.  One  of  these,  No.  5941,  presents  a  practically  complete  carapace 
and  a  few  fragments  of  the  plastron;  the  other,  No.  5945,  consists  of  a  portion  of  the  carapace 
and  some  parts  of  the  plastron.  These  remains  show  great  resemblances  to  P.  aedemius,  and 
it  is  possible  that  they  should  be  referred  there,  and  that  P.  molopinus  is  not  different  from 
the  former  species.  There  is,  however,  one  difference  between  the  two  forms  which  appears 
to  be  constant.  This  is  found  in  the  ornamentation  of  the  outer  surfaces.  Little  if  any  differ- 
ence is  to  be  seen  in  the  character  of  the  welts,  but  the  pits,  or  punctae,  of  P.  molopinus  are 
smaller  and  closer  together  than  they  are  in  P.  cedemius.    In  the  latter  there  are  usually  only 

3  or  4  pits  in  a  space  of  10  mm.;   while  in  P.  molopinus  there  are  quite  constantly  6  or  7, 

occasionally  but  5.  To  the  eye,  the  sculpture  of  the 
latter  has  a  much  finer  appearance.  In  the  case  of  both 
species,  the  longitudinal  welts  are  broken  up,  on  the  last 
costals,  into  elongated  tubercles.  It  is  also  to  be  noted 
that  the  pits  and  punctae  of  P.  molopinus  are  more  gen- 
erally distributed  over  the  carapace  than  they  are  in 
P.  cedemius. 

In  P.  ledemius  the  neurals,  the  proximal  ends  of 
most  of  the  costals,  and  the  whole  of  the  hindermost  cos- 
tals, are  smooth  or  nearly  so,  except  where  varied  by 
the  presence  of  welts. 

The  sculpture  on  No.  5941  is  not  very  distinct,  a 
fact  that  is  due  principally  to  the  dirty  color  of  the  speci- 
men. No.  5945  is  of  a  clear  sage-green  and  has  been 
weathered  free  from  all  matrix.  It  shows  the  welts  and 
the  punctae  with  great  distinctness. 

No.  5941  f plate  85,  fig.  3;  text-fig.  642)  has  a  length 

of  200  mm.  and  a  width  of  180  mm.     It  resembles  closely 

the  specimen.  No.  5978,  which  has  been  described  here 

as  P.  wdemius.     It  was,  in  life,  evidently  quite  convex. 

It  differs  from  P.  cedemius,  as  represented  by  No.  5978, 

in  having  the  costals  of  the  sixth  pair  wholly  separated 

by  the  sixth  neural.    No.  5945  differs  from  No.  5978  in 

the  same  way;    but  it  differs  from  No.  5941  in  having 

a  minute  seventh  neural.     This  neural  is  regarded  as  having  no  specific  value.     No.  5945 

further  differs  from  No.   5941    in  the  somewhat   broader  neurals,   and   in   having  the  free 

borders  of  the  costals  less  abruptly  beveled. 

Of  both  specimens,  No.  5941  and  No.  5945,  the  mesial  end  of  the  hyoplastron  is  present. 
It  differs  from  the  same  region  in  P.  cedemius  in  having  a  notch  in  the  front  border,  mesiad 
of  the  process  against  which  the  outer  end  of  the  entoplastron  rests;  but  whether  or  not  this 
might  appear  with  greater  age  is  uncertain.  The  distal  end  of  the  hypoplastron  is  present  in 
No.  5945.  It  differs  somewhat  from  that  of  P.  cedemius,  but  it  is  impossible  to  say  how  con- 
stant this  difference  is  likely  to  be. 

The  sculpture  of  the  plastron  differs  from  that  of  the  plastron  of  P.  aedemius  in  consisting 
of  smaller  and  more  closely  placed  pits  and  punctae.  Of  course,  in  making  the  comparison 
corresponding  regions  must  be  compared. 

Both  the  specimens  here  referred  to  P.  molopinus  were  secured  in  the  Bridget  beds  of  the 
western  end  of  Grizzly  Buttes.  Cope  figures  specimens  from  the  Wasatch  of  New  Mexico 
under  the  name  P.  communis.  These  are  indicated  in  the  text  (Wheeler  Surv.,  iv,  p.  50)  as 
"var.  ii,"  but  in  the  explanation  of  plate  xxv  as  "var.  i."  We  must  be  uncertain  about  this 
identification  until  additional  materials  of  the  supposed  molopinus  have  been  secured  in  the 
Wasatch  beds. 


Fig.    642. — Plastomenus     molopinus. 
Carapace.  Xj.  No.  5941  A.M.N.  H. 


TRIONYCHID^.  483 

FamUy  TRIONYCHIDiE. 
Trionychoidea  having  the  carapace  devoid  of  peripheral  bones,  except  in  the  case  of 
Tnotiyx  {Emyda  Gray),  in  vi^hich  the  few  nodules  may  be  of  secondary  origin.  Epiplastra 
separated  from  the  hyoplastra  by  lateral  prolongations  of  the  slender,  archt  or  V-shaped  ento- 
plastron.  More  or  less  extensive  fontanels  between  the  hyoplastra,  hypoplastra,  and  xiphi- 
plastra  of  the  two  sides.  Pelvis  not  suturally  joined  to  either  the  carapace  or  the  plastron. 
So  far  as  known,  no  epidermal  scutes.     Only  3  digits  with  claws. 

The  Trionychidae  constitute  a  family  of  tortoises  remarkable  on  account  of  their  structure, 
their  numbers,  their  geographical  distribution,  and  their  geological  history.  The  oldest  forms 
at  present  known  to  us  come  from  the  Upper  Cretaceous  of  New  Jersey,  Wyoming,  Montana, 
and  Alberta,  British  America.  It  is  probably  not  now  possible  to  determine  which  deposits 
are  the  older,  the  lower  marl  beds  of  New  Jersey,  which  furnish  the  little  known  Amyda  prisca 
and  AI  halophtla,  or  the  Judith  River  beds,  from  which  we  obtain  Aspideretes  coalescens, 
A.  foveatus,  and  A.  splendidiis.  So  far  as  the  shells  are  concerned,  we  find  in  the  Judith  River 
forms  only  specific  differences  when  compared  with  living  species.  Aspideretes  beecheri,  of  the 
Laramie  and  probably  too  of  the  Judith  River  beds,  furnishes  practically  all  portions  of  the 
skeleton,  except  the  skull;  and  these  agree  in  all  essential  respects  with  the  skeletons  of  living 
trionychids.  So  far  as  the  writer  is  aware,  the  oldest  known  trionychid  skull  is  that  of  Con- 
chochelys  admtrabtlis  Hay  of  the  Puerco  deposits.  This  presents  some  differences  when 
compared  with  modern  trionychids.  The  next  oldest  skull,  that  oi  Aspideretes  singularis,  of  the 
Torrejon,  differs  little  from  that  of  Platypeltus  ferox,  now  living  in  Florida. 

Trionychids  are  at  present  found  in  Asia,  Africa,  and  North  America.  Asia  furnishes  at 
least  15  species,  Africa  5  species,  and  North  America  about  7. 

All  these  data  point  to  a  very  ancient  origin  for  the  Trionychidae.  We  may  expect  to  find 
more  primitive  forms  in  fresh-water  deposits  of  the  Lower  Cretaceous  or  even  in  those  of  the 
Jurassic.  It  is  probable  that  these  primitive  forms  will  approach  more  closely  the  Cryptodira 
than  do  the  Plastomenidae. 

//'.   Skull  broad,  with  narrowed  pterygoids  and  wide  maxillary  alveolar  surfaces Conchochelys 

//■*.  Skull  unknown;  carapace  and  plastron  covered  with  pustular  elevations Helopanoplta 

//'.  Skull  usually  not  so  broad;    pterygoid  region  of  the  palate  broad: 

a^.   Plastron  smooth;    no  ridges  and  pits Axestemys 

a'.  Carapace  and  plastron  ornamented  with  ridges  and   pits. 

1.  Eight   pairs  of  costal   bones;    a   preneural   present Aspideretes 

2.  Eight  pairs  of  costal  bones;    no  preneural Amyda 

3.  Seven  pairs  of  costals,  or  those  of  the  eighth  pair  vestigial;  no  preneural.  .  Platypeltis 

Genus  CONCHOCHELYS  Hay. 

Skull  broad.  Masticatory  surfaces  broad  and  concave.  Pterygoid  region  narrow.  Basi- 
occipital  region  short.  Choanae  behind  the  orbits.  Posterior  squamosal  process  apparently 
much  shortened. 

Type:    Conchochelys  admirahilis  Hay. 

In  its  broadened  form,  its  narrowed  pterygoid  region,  and  in  its  apparently  abbreviated 
posterior  squamosal  processes,  this  trionychid  presents  such  deviations  from  known  genera  that 
the  writer  is  led  to  the  conclusion  that  it  represents  a  genus  distinct  from  all  others  hitherto 
described.  Until  more  shall  have  been  discovered  regarding  the  structure  of  the  animal,  the 
characters  given  above  may  serve  to  distinguish  this  genus.  The  name  Conchochelys,  given 
in  reference  to  the  supposed  nature  of  the  food  of  the  turtle,  was  first  publisht  in  the  Bulletin 
of  the  American  Museum  of  Natural  History,  vol.  xxi,  1905,  page  335. 

Conchochelys  admirahilis  Hay. 
Plate  88,  figs.  1-3. 
Conchochelys  admirahilis.  Hay,  Bull.  Amer.  Mus.  Nat.  Hist,  xxi,  1905,  pp.  335-^38,  figs.  1-3. 

The  skull  which  is  here  described  was  collected  in  the  year  1892  by  Mr.  O.  A.  Peterson, 
who  accompanied  Dr.  J.  L.  Wortman,  then  in  charge  of  a  collecting  party  from  the  American 
Museum  of  Natural  History.    It  was  obtained  in  the  Puerco  beds  of  the  northern  part  of  New 


484  KOSSIL    TURTLES    OF    NORTH    AMERICA. 

Mexico.  The  exact  locality  is  Coal  Creek  Canyon,  in  the  southeastern  corner  of  San  Juan 
County.  The  specimen  bears  the  catalog  number  6090.  The  skull  is  quite  complete,  with  the 
exception  of  the  absence  of  the  lower  jaw.  Figures  of  the  object  as  seen  from  above,  from  below 
and  from  the  right  side  are  presented. 

The  skull  is  that  of  a  large  and  evidently  aged  individual  and  no  sutures  are  to  be  observed. 

The  premaxilla  and  the  anterior  extremities  of  the  maxillae  are  missing,  but  the  missing 
parts  would  add  little  to  the  length  of  the  snout.  The  distance  from  the  front  of  the  nasal  bones 
to  the  extremity  of  the  occipital  condyle  is  127  mm.  The  breadth  across  the  zygomatic  arches 
is  1 1 1  mm.;  the  distance  from  the  outside  of  one  quadrate  to  that  of  the  other  appears  to  have 
been  about  88  mm.;  and  the  width  across  the  skull  at  the  middle  of  the  tympanic  cavities  is 
108  mm.  It  will  be  seen  therefore  that  the  roof  of  the  tympanic  cavity  projects  much  over  the 
pedicels  of  the  quadrates.  Usually  in  living  trionychids  the  breadth  across  the  pedicels  of  the 
quadrates  is  as  great,  or  nearly  as  great,  as  the  breadth  at  any  other  part.  The  hinder  portion 
of  the  skull  is  shortened.  The  extremity  of  the  condyle  is  only  13  mm.  behind  the  line  joining 
the  quadrates.  In  a  specimen  of  Platypeltis  ferox  94  mm.  long  from  the  snout  to  the  condyle, 
the  latter  is  placed  at  a  distance  of  17  mm.  behind  the  quadrates.  Relatively  to  other  species 
of  the  group  the  skull  is  broad,  the  breadth  being  86  per  cent,  of  the  length.  In  Pelochelys 
cantoris,  whose  skull  is  relatively  broad,  the  width  of  the  latter  is  82  per  cent,  of  the  length. 
The  skull  of  the  species  under  description  is  flat,  and  this  appears  to  be  due  in  no  measure 
to  crushing.  Placed  on  a  level  surface,  the  skull  has  its  crest  elevated  to  a  height  of  65  mm. 
The  snout  was  blunt.  The  skull  maintains  its  breadth  as  far  forward  as  the  line  joining 
the  posterior  borders  of  the  orbits,  where  it  is  98  mm.;  then  the  outlines  converge  rapidly. 
The  interorbital  space  is  15  mm.  wide.  The  orbits  look  outward,  forward,  and  upward,  and 
are  circular,  with  diameters  of  22  mm.  From  the  orbits  the  sides  of  the  face  slope  downward 
and  outward. 

The  anterior  nasal  opening  appears  to  have  had  little  height,  rising  only  8  mm.  above  the 
•floor  of  the  passage.  Its  breadth  has  been  20  mm.  The  lateral  crests  of  the  parietals  converge 
rapidly  and  meet  opposite  the  fronts  of  the  prootics.  The  postorbital  arch  has  a  width  of 
1 1  mm;  the  zygomatic  arch  a  width  of  only  8  mm.  in  the  middle  of  its  length.  At  its  anterior 
inferior  border  it  starts  from  the  hinder  extremity  of  the  cutting-edge  of  the  maxilla,  and  ascend- 
ing passes  backward  to  the  front  of  the  tympanic  cavity.  It  is  far  more  archt  than  that  of 
living  trionychids.  The  tympanic  cavity  is  relatively  longer  than  that  o(  Plat  y  pelt  is  ferox,  the 
length  being  33  mm.,  one-fourth  the  length  of  the  skull.  In  ferox  the  length  of  the  cavity  is 
about  one-fifth  the  length  of  the  skull. 

In  contradistinction  to  P.  ferox,  the  upper  border  of  the  squamosal  is  not  rolled  down- 
ward, but  stands  out  as  a  sharp  edge.  Moreover,  there  does  not  appear  to  have  existed 
that  long  backwardly  directed  process  of  the  squamosal  and  paroccipital  which  we  find  so 
conspicuous  in  the  living  trionychids.  It  is  possible  that  this  process  was  originally  somewhat 
longer  than  now  appears;  but  it  could  have  been  but  little  longer. 

The  fossa  inclosed  by  the  zygomatic  arch  is  greatly  different  from  that  of  Platypeltis. 
In  the  latter,  and  perhaps  in  all  living  members  of  the  Trionychidae,  the  fossa  is  longer  than 
broad.    In  this  Puerco  species  the  length  is  34  mm.,  the  width  about  38  mm. 

The  occipital  crest  has  been  injured  and  is  partly  missing.  It  included  a  lower  horizon- 
tally expanded  border  and  a  thickened  superior  border.  The  latter  may  be,  so  far  as  preserved, 
the  backwardly  prolonged  parietals. 

The  upper  jaws  were  furnisht  with  subacute  cutting-edges.  From  these  the  palate  rises 
in  a  high  vault,  26  mm.  above  the  cutting-edges.  The  choanae  are  removed  far  backward, 
their  front  borders  touching  a  perpendicular  plane  thru  the  posterior  borders  of  the  orbits. 
The  distance  from  the  premaxillae  to  these  choanae  was  about  50  mm.  There  was,  therefore, 
an  enormous  crushing  surface  on  the  upper  jaws,  and  we  may  conclude  with  safety  that  the 
animal  was  accustomed  to  devouring  a  prey  that  was  protected  by  hard  coverings,  such  as 
mollusks.    From  each  choana  a  groove  in  the  roof  of  the  mouth  extends  backward  about30mm. 

The  pterygoid  region  is  only  36  mm.  wide.  In  the  specimen  of  Platypeltis  ferox  referred 
to,  the  pterygoid  region  is  eight-tenths  the  width  of  the  upper  jaws.  This  region  in  the  fossil 
is  very  concave  transversely.     The  articulation  of  the  quadrate  was  about  20  mm.  wide. 

This  skull  is  the  most  ancient  one  of  the  Trionychidae  that  is  at  present  known. 


TRIONYCHID^.  485 

Genus  HELOPANOPLIA  nov. 

Trionychids  with  hyoplastron  and  hypoplastron  not  co-ossified,  and  with  both  the  carapace 
and  the  plastron  ornamented  with  numerous  tubercles  which  resemble  the  rounded  heads  of 
small  nails.    The  tubercles  in  some  places  coalescing  to  form  short  ridges. 

Derivation  of  name:  ijKoq,  a  nail  used  for  ornament;  TravoirXm,  full  armor. 

Type:    Helopanoplia  distmctn  Hay. 

This  genus  differs  from  Trionyx  (Eniydn  Gray)  in  having  the  hyoplastron  free  from  the 
hypoplastron  until  advanced  age.  In  Trionyx  the  two  bones  co-ossify  at  a  very  early  stage. 
Doubtless  better  materials  of  the  fossil  species  will  reveal  other  differences. 

Helopanoplia  distincta  sp.  nov. 
Plate  88,  figs.  4,  5. 

The  only  known  materials  which  indicate  the  former  existence  of  this  species  are  a  frag- 
ment of  one  costal  plate  and  a  portion  of  one  hypoplastron  or  hyoplastron.  These  fragments 
were  collected  by  Prof.  J.  B.  Hatcher,  while  in  the  employ  of  Prof.  O.  C.  Marsh,  at  that 
time  vertebrate  paleontologist  of  the  U.  S.  Geological  Survey.  The  remains  were  secured  in 
the  Laramie  deposits  of  Lance  Creek,  Converse  County,  Wyoming,  and  indicate  a  rather 
large  and  heavy  soft-shelled  tortoise.  The  fragment  of  carapace  (plate  88,  fig.  4)  is  a  part  of 
the  upper  half  of  a  costal  plate.  It  is  only  34  mm.  long  and  does  not  extend  entirely  across  the 
plate,  but  apparently  lacks  little  of  doing  so,  since  the  thickening  of  the  rib  lies  rather  closer 
to  the  side  bearing  the  suture  than  to  the  other.  The  thickness  thru  the  sutural  border  is 
10  mm.;  thru  the  rib,  13.5  mm.  at  the  proximal  end  of  the  bone,  and  10.5  mm.  at  the  distal  end. 

Whether  the  fragment  of  the  plastron  (plate  88,  fig.  5)  belongs  to  the  hyoplastron  or  to  the 
hypoplastron  can  not  be  determined  with  certainty;  it  seems  to  belong  to  the  latter  of  the  left 
side.  The  piece  formed  a  portion  of  the  plastron  between  the  fore  and  hind  legs.  The  bone 
is  thickened  most  at  the  end  farthest  from  the  midline,  being  there  15  mm.  Toward  the  mid- 
line the  thickness  becomes  reduced  to  9  mm.  At  the  free  border  the  bone  is  suddenly  reduced 
in  thickness  and  the  edge  is  subacute. 

The  ornamentation  of  this  species  resembles  much  that  of  Trton  yx  granosus,  called  Emyda 
granosa,  in  Boulenger's  Catalogueof  Chelonians.  The  costal  plate  is  thickly  studded  with  small, 
rounded  tubercles  which  look  like  the  heads  of  insect  pins.  Four  or  five  of  these  occupy  a  dis- 
tance of  5  mm.  The  distance  between  the  tubercles  is,  on  an  average,  somewhat  less  than  the 
diameters  of  the  tubercles  themselves.  Perhaps  half  of  the  tubercles  become  connected  in 
twos  and  threes  to  form  short  and  winding  ridges.  Similarly,  but  to  a  greater  extent,  the 
tubercles  of  Trionyx  granosus  coalesce  along  the  middle  of  the  back. 

On  the  piece  of  plastron  the  tubercles  are  less  crowded  and  seldom  join  to  form  ridges. 

It  is  believed  that  this  style  of  ornamentation  is  so  different  from  that  of  the  other  species 
of  Trionychidae  that  a  distinct  genus  is  indicated. 

Genus  ASPIDERETES  Hay. 

Carapace  with  8  pairs  of  costal  plates;  one  or  more  of  the  posterior  pairs  in  contact  on  the 
midline.  A  preneural  plate  between  the  nuchal  and  the  true  first  neural.  Young  of  living 
species  with  numerous  longitudinal  dorsal  dermal  ridges  or  series  of  tubercles. 

The  type  of  this  genus  is  Trionyx  gangeticus  of  Cuvier.  Other  living  species  are  A .  hurum 
and  A.  leithii.  Trionyx  melitensis  described  by  Dr.  Lydekker  from  the  Miocene  of  Malta  must 
be  referred  to  the  same  genus. 

That  which  distinguishes  this  genus  from  Amyda  is  the  presence  of  a  preneural  bone.  The 
writer  regards  this  as  a  primitive  character  which  has  been  lost  by  the  other  genera  of  Trio- 
nychidae.   This  bone  is  present  in  the  Plastomenidae  also  and  in  some  of  the  Baenidae. 

It  is  a  noteworthy  fact  that  no  trionychid  from  the  Cretaceous  deposits  is  known  to  be 
without  this  bone.  Two  Upper  Cretaceous  species  are  arranged  under  Amyda,  viz.,  A. 
prisca  and  A.  halophila,  but  these  are  based  on  fragments  only  and  it  is  quite  probable  that 
better  materials  would  show  the  presence  of  the  preneural. 


486  FOSSIL    TURTLES    OF    NORTH    AMKRICA. 

Key  to  the  Species  of  Aspideretes. 

A'^.  Judith  River  and  Laramie  species: 

1.  Shell  of  moderate  size,  broad;  middle  region  of  carapace  with  round  pits,  somewhat 

scattered;  distal  ends  of  costals  crossed   by   furrows  and  ridges;    plastron   with 

twisted  ridges    foveatus 

2.  Shell  large,  broader  than  long;  pits  numerous  everywhere,  in  rows  across  distal  ends 

of  costals;  nuchal  excavated  in   front coalescens 

3.  Shell   large,   considerably   broader  than   long;    sculpture    like    that    of   coalescens, 

but   less   in  rows  across  outer  ends  of  costals;   nuchal  convex  in  front,  straight 

behind splenJiJus 

4.  Shell  nearly  as  broad  as  long,  sculpture  of  carapace  as  in  coalescens;  nuchal  straight 

or  convex  in  front,  shorter  from  side  to  side  than  splendtdus;  sculpture  of  plastron 

finer  than  in  coalescens heechert 

5.  Nuchal  with  thick  abrupt  free  border;  its  width  equal  to  half  the  distance  from  pre- 

neural  to  outer  end;  thickness  at  preneural  border  of  type  4  mm.;  pits  not  large.  .  .     jontanus 

6.  Nuchal  with  thick  abrupt  free  border;  width  probably  less  than  in  A.  jontanus  and 

thickness  greater;    pits  large  and  irregular  in  arrangement austerus 

7.  Nuchal  three-fifths  as  wide  as  distance  from  preneural  to  outer  end;   free  border 

beveled  off;  bone  at  preneural  border  7  mm.  thick,  preneural  as  wide  as  nuchal.  .  vorax 

A^.  Arapahoe  species: 

A  species  not  well  known.   Pits  of  costal  bones  shallower  than  in  the  species  numbered 

2,  3  and  4,  and  with  less  abrupt  walls vagans 

A^.  Fort  Union  and  Puerco  species: 

1.  Disk  of  carapace  longer  than  wide;  nuchal  joined  by  its  whole  length  to  preneural 

and  first  costals;   the  outer  end  hardly  reaching  the  rib  of  the  first  costal;  5  to  7 

pits  in  25  mm.  line sagatus 

2.  As  in  sagatus,  but  the  outer  end   of  the   nuchal   extending  across  the   rib  of  the 

first  costal;  6  to  8  pits  in  a  20  mm.  line  on  proximal  ends  of  costals;  only  3  or  4 

on  distal  ends singularis 

3.  Disk  wider  than   long;    sculpture  obscure   in  known  specimen,  but  finer  than  in 

sagatus nassau 

4.  Disk  longer  than  wide;   nuchal  loosely  joined  to  preneural  and  costals;  fontanels 

behind  it puercensis 

A*.  Bridger  species: 

1.  Preneural  doubtfully  present;  a  fontanel  on  each  side  of  its  position.     Pits  of  cara- 

pace large guttatus 

2.  A  well-developed  preneural  and  no  fontanels;  sculpture  somewhat  coarser  than   in 

either  the  preceding  or  the  following  species;    second  and    third    neurals  about 

half  as  wide  as  long ellipticus 

3.  A  well-developt  preneural  and  no  fontanel;    sculpture  like  that  oi  guttatus;    second 

and  third  neurals  nearly  two-thirds  as  wide  as  long grangeri 

Aspideretes  foveatus  (Leidy). 
Plate  89,  figs.  I,  2;   text-figs.  643,  644. 

Trionyx  foveatus,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  viii,  1856,  pp.  73,  312;  Amer.  Jour.  Sci.,  (2) 
XXII,  1856,  p.  120;  Trans.  Amer.  Philos.  Soc,  xi,  i860,  p.  148,  plate  xi,  figs.  1-3. — Cope,  Synop. 
Ext.  Bat.  Rept.  and  Aves  N.  A.,  in  Trans.  Amer.  Philos.  Soc,  xiv,  1869,  p.  152;  Bull.  U.  S.  Geol. 
and  Geog.  Surv.  Terrs.,  I,  1879,  No.  2,  p.  29;  Vert.  Tert.  Form.  West,  1875,  p.  260;  Bull.  U.S. 
Geol.  and  Geog.  Surv.  Terrs.,  1877,  in,  p.  573. — Lambe,  1902,  Geol.  Surv.  Canada,  Summary 
Rept.  for  1901,  p.  81,  plates  i,  ii;  Cont.  Canad.  Palaeont,  in  (4  to),  pt.  11,  p.  33,  plate  i,  figs,  i,  2, 
text-fig.  I. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  p.  454,  1902. — Hatcher,  Bull.  U.  S.  Geol. 
Surv.  No.  257,  1905,  p.  72. 

The  specimens  described  by  Dr.  Leidy  under  the  name  Trionyx  foveatus  were  collected  by 
Dr.  F.  V.  Hayden  partly  in  the  Judith  River  beds  of  Montana  and  partly  in  beds  supposed  to 
be  of  the  same  age,  near  Long  Lake,  in  what  is  now  Burleigh  County,  North  Dakota. 

Those  from  the  Judith  River  basin  are  described  as  consisting  of  small  fragments  of  costal 
and  sternal  plates;  and  of  these  the  proximal  half  of  a  costal  plate  and  two  fragments  of  a 
hypoplastron  are  described  and  figured  in  Leidy's  paper  of  i860  on  "The  Extinct  Vertebrate 


TRIONYCHID^. 


+87 


Fauna  from  the  Judith  River  and  Great  Lignite  Formations  of  Nebraska,"  publisht  as  cited 
above.  These  parts,  now  preserved  in  the  Academy  of  Natural  Science  at  Philadelphia, 
must  be  regarded  as  the  types  of  the  species.  A  fragment  of  the  right  last  costal  plate,  found 
near  Long  Lake,  was  identified,  with  some  doubt,  as  belonging  to  the  same  species,  and 
furnisht  fig.  3  of  Leidy's  plate  above  cited.  This  specimen  is  now  in  the  National  Museum  at 
Washington  and  bears  the  catalog  number  990. 

As  regards  the  type  specimens,  there  seems  to  be  no  certainty  that  the  costal  plate  and  the 
fragments  of  plastron  were  found  associated.  We  must,  however,  for  the  present,  assume 
that  they  belong  to  the  same  species.  Should  future  discoveries  prove  that  two  species  are 
involved,  we  shall  have  to  take  the  costal  plate  as  the  type. 

This  costal  is  22  mm.  wide,  5  mm.  thick  at  the  sutural  margins,  and  7  mm.  thick  thru 
the  rib.     The  ornamentation  consists  of  pits  of  varying  size  and  shape  separated  by  ridges 

whose  summits  are  usually  flat.  There 
are,  in  general,  5  pits  in  a  line  10  mm. 
long.  The  pits  are,  as  stated  by  Leidy, 
smaller  at  the  proximal  end  of  the  costal 
than  further  outward;  but  this  increase 
in  size  is  due  to  the  narrowing  of  the 
separating  walls,  not  to  a  reduction  in 
the  number  of  pits  in  a  given  line.  The 
pits  are  concave,  and  give  the  impression 
of  having  been  scoopt  by  an  engraver 
in  a  level  surface.  Near  the  sutural  mar- 
gins of  the  costal  the  pits  are  almost 
wholly  wanting  and  the  surface  is  level 
and  smooth. 

The  fragments  of  the  plastron  of  the 
type  are  8  mm.  thick.  The  lower  surface 
is  covered  with  short  vermiculated  ridges, 
some  of  which  inosculate  with  the  neigh- 
boring ridges  while  others  do  not. 
Scattered  among  these  are  small  dot-like 
elevations. 

Mr.  L.  M.  Lambe,  of  the  Geological 
Survey  of  Canada,  described,  as  cited  in 
the  synonymy  above,  a  nearly  complete 
carapace  and  some  plastral  bones  which 
he  refers  to  this  species.  These  he 
secured  in  the  Belly  River  deposits,  on 
the  Red  Deer  River,  in  Alberta,  British  America.  The  nuchal  bone  is  missing  from  the  cara- 
pace. The  length  of  the  carapace  (plate  89,  fig.  i;  text-fig.  643)  as  found,  is  163  mm.  The 
width  of  the  nuchal  has  been  estimated  by  Lambe  as  5  mm.  but  it  is  probable  that  the 
width  fore  and  aft  was  considerably  greater.    The  maximum  width  of  the  carapace  is  214  mm. 

The  rear  is  broadly  rounded,  and  the  upper  surface  is  moderately 
convex.  There  are  present  a  preneural,  6  neurals,  and  8  pairs  of 
costals.     The  genus  Asptderetes  is  therefore  indicated. 

The  preneural  is  short,  being  18  mm.  wide  and  12  mm.  long. 
The  4  anterior  neurals  are  broader  behind  than  in  front;  the 
fifth  is  a  parallelogram;  the  sixth  is  broad  in  front  and  pointed 
behind.  The  dimensions  of  the  neurals  are  given  in  the  table. 
The  eighth  costals  are  small,  almost  vestigial,  as  in  some 
species  of  Platypeltts,  the  lateral  extent  of  one  being  about  22 
mm.;  of  the  other,  20  mm.  Each  lies  in  a  notch  in  the  costal  in 
front  of  it,  and  they  do  not  come  into  contact  at  the  midline,  the 
latter  condition  being  probably  an  individual  peculiarity.  The  sculpture  resembles  closely  that 
of  Leidy's  type.    It  is  thus  described  by  Lambe: 


Fig.  643. — Asptderetes  foveatus.     Carapace. 
Figure  by  L.  M.  Lambe. 

d,  line  showing  curvature  of  shell  from  side  to  side;  t.p.  i,  c./i.  8, 
the  costal  bones;  pren,  preneural;  n.  i,  rj.  6,  the  neurals;  nu.  p, 
nuchal  bone. 


Neurals. 

Length. 

width. 

I 

20 

Ig 

2 

22 

,6 

3 

20 

14 

4 

21 

'7, 

5 

ig 

II 

6 

i6 

14 

488 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


Small,  shallow,  rounded  depressions  mark  the  surface  of  the  neurals  and  the  inner  ends  of  the  costais. 
In  the  latter,  as  the  distance  from  the  neurals  increases,  the  depressions  gradually  grow  larger  and  more 
decided,  becoming  often  reniform  or  oval,  and  frequently  coalescing,  until  in  the  distal  ends  of  the  costais 
a  few  more  or  less  continuous  furrows  are  formed  parallel  to  the  outer  margins  of  the  plates.  These 
furrows  are  a  conspicuous  feature  in  the  sculpture;  they  are  not  so  well  marked  on  the  posterior  margin 
of  the  carapace,  but  are  well  developed  near  the  front  edges  of  the  first  costais.  In  the  neurals  and 
inner  halves  of  the  costais  there  is  a  narrow,  smooth  strip,  devoid  of  all  sculpture,  bordering  the  sutures. 

None  of  the  plastral  bones  referred  by  Lambe  to  this  species  were  associated  with  the 
carapace  described.  The  author  referred  to  states  that  the  plastral  bones  belonged  to  individuals 
of  larger  size  than  that  to  which  the  carapace  belonged.  A  comparison  of  the  bones  with 
corresponding  parts  of  individuals  belonging  to  Platypeltis  ferox  and  P.  spinifera  shows  that 
the  individual  represented  by  the  carapace  may  have  been  as  large  as  the  others  or  even  larger. 
In  form  the  plastron  (plate  89,  fig.  2;  text-fig.  644)  resembled  much  that  of  the  living 
species  just  mentioned.    The  sculpture  consists  of  ridges  and  intervening  furrows  of  varying 

length  and  of  irregular  direction. 
Of  the  ridges  there  are  about  9 
in  a  line  20  mm.  long.  On  the 
outer  ends  of  the  bones  the  ridges 
run  parallel  with  the  long  axis  of 
the  animal.  On  the  inner  half, 
the  ridges  are  shorter,  less  eleva- 
ted, and  irregular  in  their  course. 
In  the  collection  of  fossil  verte- 
brates made  in  the  Judith  River 
basin  by  Mr.  C.  H.  Sternberg,  in 
1876,  for  Professor  Cope,  there 
are  many  fragments  of  costal 
bones  which  belongtothisspecies; 
but  they  throw  no  additional  light 
on  it. 

From  the  Laramie  beds  at  Hell 
Creek,  Montana,  Mr.  Barnum 
Brown  has  brought  to  the  Amer- 
ican Museum  of  Natural  History 
fragments  of  a  trionychid  that 
resemble  very  closely  similar  fragments  from  the  Judith  River  basin.  Three  consecutive 
neurals  and  portions  of  costais  have  the  number  1017.  Had  they  been  found  in  Judith  River 
deposits  they  would  without  hesitation  be  referred  to  A.  foveatus.  Perhaps  only  the  finding 
of  a  complete  shell  of  this  Laramie  form  will  settle  the  questions  involved. 

The  character  of  the  sculpture,  especially  that  of  the  central  regions  of  the  carapace, 
distinguishes  A.  foveatus  from  any  other  of  the  Judith  River  species  with  which  it  is  likely  to 
be  compared. 

The  specimens  of  Trtonyx  foveatus  cited  by  Prof.  O.  C.  Marsh  as  having  been  found  in 
the  Ceratops  beds  near  Denver,  Colorado,  belong  probably  to  Aspideretes  beecheri;  but  the 
present  writer  has  not  seen  the  materials  on  which  Marsh's  statement  was  founded. 


Fig.  644. — Aspideretes  foveatus.      Right   hyoplastron   and   hypo- 
plastron.     X  §■     Reduced  from  Lambe's  figure. 

hpo,  hyoplastron;   hypOf  hypoplastron. 


Aspideretes  coalescens  (Cope). 
Plate  88,  fig.  6;    plate  90,  fig.  i;   teit-fig.  645. 

Plastomenus  coalescens,  CopE,  Proc.  Acad.  Nat.  Sci.  Phila.  1875,  P-  9  ("°  description);  Brit.  N.  A., 
Bound.  Comm.  Report  on  Geol.  and  Resources  49th  Par.,  1875,  P-  i?iT'  Vert.  Cret.  Form.  West, 
1875,  pp.  93,  261,  plate  viii,  figs.  6,  7. — Lambe,  Ottawa  Naturalist,  xiii,  1899,  pp.  68,  70;  Summary 
Report  Geol.  Surv.  Canada,  1898  (1899),  p.  182-190. — Hatcher,  Bull.  U.  S.  Geol.  Surv.  No.  257, 
1905,  p.  74. 

Trtonyx  vagans,  .'CoPE,  Bull.  U.  S.  Geol.  Surv.  Terrs.,  Ill,  1877,  p.  573. — Lambe,  Contrib.  Canad.  Pal- 
aeont.,  iii  (410),  1902,  p.  36,  plate  i,  figs.  3,  4,  text-fig.  3. 

Trionyx  coalescens,  Hay,  Bibliog.  and  Cat.  F'oss.  Vert.  N.  A.,  1902,  p.  454. 

Plastomenus  (Trionyx)  coalescens,  Osborn,  Contrib.  Canad.  Palaeont.,  Ill  (4  to),  1902,  pp.  12,  16. 


TRIONYCHIDj^. 


489 


This  species  was  based  on  a  specimen  which  was  collected  in  the  basin  of  Milk  River, 
south  of  Wood  Mountain,  Assiniboia,  British  America,  and  which  is  now  in  the  collection  of 
the  Geological  Survey  of  Canada.  Professor  Cope's  earliest  mention  of  the  name  was  not 
accompanied  by  a  description ;  but  in  the  same  year  both  description  and  figures  were  publisht. 
The  figures  represent  the  bones  half  the  natural  size. 

Professor  Cope  thought  that  there  had  been  secured  portions  of  both  the  carapace  and 
plastron  of  this  species;  but  an  examination  shows  that  all  the  parts  belong  to  the  plastron. 
The  bones  which  furnisht  his  fig.  6  and  6a  (Vert.  Cret.  Form.  West,  plate  viii),  instead  of  being 
parts  of  costal  plates,  are  the  median  ends  of  the  right  hyoplastron  and  hypoplastron;  while 
the  original  of  fig.  J  is  made  up  of  other  parts  of  the  same  bones.  In  the  figure  here  presented 
(fig.  645)  that  portion  on  the  left  of  the  curved  line  running  from  A  to  B  is  the  part  represented 
by  Cope's  fig.  7,  the  lower  end  of  the  latter  figure  corresponding  to  the  left  side  of  our  fig.  645. 
The  part  of  the  latter  figure  which  lies  on  the  right  of  the  line  from  A  to  C  represents  the  same 
mass  of  bone  as  Cope's  fig.  6.    The  portion  of  our  fig.  645  lying  in  the  triangle  ABC,  except 

the  part  dotted,  represents  a  frag- 
...•■'[.i:.;-^,    .       ment  of  bone  which  was  present  with 
,.-'  ''..••■        the  others,  but  which  Cope  did  not 

bring  into  relation  with  the  rest  of 
the  plastron.  This  comes  into  accu- 
rate contact  with  the  other  two 
pieces  and  connects  them. 

Professor  Cope  thought  too  that 
the  sutures  between  the  various 
bones  had  been  obliterated,  but  one 
may  be  traced  from  end  to  end  of 
the  united  fragments.  In  Cope's 
fig.  7  the  suture  would  run  perpen- 
dicularly thru  the  middle  thereof; 
while  in  fig.  6  it  would  start  23  mm. 
below  the  sharp  projection  to  the 
right  of  the  deep  notch  on  the  right 
side  and  cross  the  figure  to  a  point 
on  the  upper  margin  37  mm.  from 
the  extreme  left  angle  of  the  figure. 
We  have  in  this  specimen,  there- 
fore, a  large  part  of  the  hyoplastron 
and  hypoplastron  of  the  right  side, 
and  belonging  to  a  very  large  animal.  It  is  quite  certain  that  the  remains  did  not  belong  to 
the  genus  Plastomenus. 

The  width  of  the  plastron,  where  narrowest,  between  the  axillary  and  inguinal  notches, 
is  nearly  70  mm.,  and  the  thickness  is  18  mm.  Toward  the  median  portion  of  the  bones  the 
thickness  is  reduced  to  10  mm.  or  less.  The  process  of  the  hypoplastron  which  is  nearest  the 
hyohypoplastral  suture  and  directed  toward  the  midline  is  very  short,  leading  to  the  opinion 
that  the  fontanel  between  the  right  and  left  halves  of  the  plastron  was  narrow. 

The  ornamentation  of  the  plastral  bones  which  form  the  type  of  this  species  is  mostly 
quite  obscure.  On  the  portion  of  the  plastron  forming  the  bridge  there  are  rather  coarse 
ridges  forming  by  their  union  large  pits.  Toward  the  median  portion  of  the  plastron  the 
sculpture  becomes  mostly  effaced. 

Mr.  L.  M.  Lambe,  of  the  Canadian  Geological  Survey,  has  described,  under  the  name 
Trionyx  vagans,  a  large  specimen  of  a  trionychid,  which  he  secured  in  the  Belly  River  deposits, 
in  the  region  of  the  Red  Deer  River,  below  Berry  Creek,  in  Alberta.  The  present  writer, 
regarding  Cope's  type  of  Trionyx  vagans  as  too  small  and  imperfect  a  fragment  for  satis- 
factory comparison  with  materials  from  any  region,  except  the  type  locality  in  eastern  Colorado, 
is  compelled  to  seek  for  some  more  probable  disposition  of  Mr.  Lambe's  fine  specimen.  Since 
the  plastron  of  Cope's  Plastomenus  coalescens  indicates  a  large  trionychid  which  lived  in 
approximately  the  same  region  and  in  the  same  geological  period,  it  appears  to  be  best  to 
refer  the  Red  Deer  River  carapace  to  the  same  species. 


Fig.  645. — Aspideretes  coalescens.     Plastron  of  type.     X  J. 
AfB,  C,  explained  in  text;   hyo,  hyoplastron;   hypo,  hypoplastron. 


490  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

The  carapace  (plate  90,  fig.  i)  referred  to  is  nearly  complete,  wanting  only  the  greater 
portion  of  the  nuchal;  and  this  was  fortunately  supplied  by  another  specimen  of  the  same 
size.  The  carapace  is  broader  than  long,  slightly  excavated  along  the  anterior  border  of  the 
nuchal,  and  truncated  behind.  The  upper  surface  was  rather  flat.  The  total  length  along  the 
midline  is  470  mm.;   while  the  maximum  width  is  590  mm. 

The  nuchal  has  a  length,  from  side  to  side,  of  290  mm.  and  a  fore-and-aft  width  of  49  mm. 
Its  anterior  border  is  sinuous,  being  excavated  at  the  midline;  its  posterior  border  is  rather 
strongly  convex  and  it  joins  the  bones  behind  it  without  intervening  fontanel.  There  is  present 
a  preneural  and  6  neurals.  The  preneural  is  coffin-shaped,  with  the  broad  end  forward.  Its 
maximum  width  is  56  mm.  The  anterior  5  neurals  are  also  coffin-shaped,  but,  as  usual  in 
trionychids,  the  narrow  end  is  directed  forward.  The  sixth  neural  is  oval  and  much  reduced. 
No  neural  is  interposed  between  the  costals  of  the  seventh  and  eighth  pairs;  and  those  of  the 
sixth  pair  meet  behind  the  sixth  neural.  The  costals  of  the  seventh  pair  are  relatively  very 
narrow,  only  36  mm.  in  the  middle  of  the  length.  The  eighth  costals  are  well  developt.  The 
nuchal  has  a  thickness  of  18  mm.  at  the  outer  end;  the  first  costal  is  9  mm.  thick  at  the  proximal 
end  and  12  mm.  at  the  distal  end.    The  thickness  at  the  center  of  the  eighth  costal  is  10  mm. 

The  sculpture  (plate  88,  fig.  6)  consists  of  a  network  of  usually  sharply  defined  ridges 
which  inclose  pits  of  varying  size.  The  ridges  are,  for  the  most  part,  narrower  than  the 
diameter  of  the  pits.  Toward  the  distal  ends  of  the  costals  the  pits  are  more  or  less  transformed 
into  furrows  which  run  parallel  with  the  free  border  of  the  carapace.  On  the  hindermost 
portion  of  the  carapace  the  pits  are  unusually  large  and  the  ridges  are  high.  Around  the  whole 
border  of  the  shell  there  is  a  nearly  smooth  band.  This  is  broadest  at  the  sides  of  the  carapace. 
On  each  side  of  the  costal  sutures  is  a  band  consisting  of  low  ridges  which  run  at  right  angles 
with  the  suture. 

In  size,  general  form,  and  sculpture,  the  carapace  which  has  been  referred  to  this  species 
resembles  closely  that  here  described  as  Aspideretes  splendidus.  The  two  are,  however, 
different  in  many  ways.  A.  coalescens  has  6  neurals,  while  A.  splendidus  has  7.  The  nuchal 
of  A.  coalescens  is  excavated  in  front  and  convex  behind,  while  in  A .  splendidus  it  is  convex 
in  front  and  nearly  straight  behind.  The  nuchal  of  the  latter  has,  likewise,  a  relatively  greater 
lateral  extent.  The  hinder  borders  of  the  two  species  are  somewhat  different,  that  of  A. 
splendidus  being  sinuously  convex,  with  a  small  median  notch,  while  that  of  A.  coalescens  is 
truncated.  In  A.  coalescens  there  is  not  much  difference  between  the  width  of  the  proximal 
and  the  distal  ends  of  the  costals  of  the  first  pair,  but  in  A.  splendidus  the  distal  ends  are  much 
narrower  than  are  the  proximal  ends.  The  same  statement  is  true  of  the  seventh  costals  of 
the  two  species.  In  A.  splendidus  there  does  not  appear  the  same  tendency  toward  the  for- 
mation of  parallel  furrows  toward  the  distal  ends  of  the  costals,  but  rather  a  tendency  toward 
the  production  of  square  cells. 

Aspideretes  splendidus  sp.  nov. 
Plate  88,  figs.  7,  8,  9;    plate  91;    text-fig.  646 

Trionyx  vagans,   .?CopE,  Proc.  Acad.  Nat.  Sci.  Phila.  1875,  p.  9;     .'Bull.  U.  S.  Geol.  and  Geog.    Surv. 
Terrs.,  in,  1877,  p.  573. —  POsborn,  Contrib.  Canad.  Palaeont.,  iii,  1902,  pp.  12,  16. 

The  specimen  which  is  taken  as  the  type  of  this  species  is  a  large,  but  somewhat  imperfect, 
carapace  in  the  American  Museum  of  Natural  History.  It  is  a  part  of  the  Cope  collection  of 
reptiles,  and  was  collected  for  Professor  Cope  in  1876,  by  Mr.  Charles  Sternberg,  from  the 
Judith  River  basin,  of  Montana.  It  has  now  the  number  3952.  The  fragments  of  which  the 
specimen  consisted  when  it  came  to  the  American  Museum  have  been  put  together,  and  it  is 
now  so  nearly  complete  that  almost  all  portions  of  the  carapace  can  be  determined  from  one 
side  or  the  other.  A  slight  doubt  now  exists  only  with  regard  to  the  presence  of  a  preneural 
and  the  amount  of  extension  of  the  ribs  beyond  the  costal  borders. 

This  species  attained  a  very  large  size.  The  width  of  the  type  specimen  is  greater  than  the 
length,  and  the  carapace  was  much  deprest.  The  sides  of  the  carapace  are  scallopt;  there  is 
a  slight  sinus  at  the  midline  behind;  and  the  anterior  border  formed  a  gentle  curve,  with  a 
slight  sinus  on  each  side  of  the  midline. 


TRIONYCHID^. 


49] 


The  total  length  in  the  midhne  is  538  mm.;  the  greatest  width,  665  mm.  The  greatest 
height  of  the  center  of  the  carapace  above  the  distal  ends  of  the  costals  is  only  about  70  mm., 
but  in  life  the  height  may  have  been  somewhat  greater.  The  nuchal  has  an  antero-posterior 
extent  of  75  mm.,  and  an  extent  from  side  to  side  of  400  mm.  There  was  probably  a  preneural 
bone,  but  this  region  is  damaged  so  that  the  presence  of  the  bone  is  uncertain.  If  it  was  not 
developt,  the  first  neural  must  have  been  very  large.  Furthermore,  there  are  some  appearances 
in  the  region  in  question  which  indicate  that  there  was  a  preneural.  The  probable  condition 
in  this  part  of  the  carapace  is  indicated  in  the  text-figure  (fig.  646).  In  the  carapace,  as  restored, 
there  seems  to  be  a  suture  between  the  inner  anterior  angle  of  the  first  left  costal  and  a  pre- 
neural; but  the  supposed  suture  may  be  merely  a  fracture.  There  is  also  a  fragment  of  bone 
which  appears  to  be  a  portion  of  the  preneural  and  a  portion  of  the  first  neural,  but  it  is  un- 
certain whether  or  not  the  fragment  belongs  where  it  is  placed.  If  present,  the  preneural  was 
probably  wider  at  its  anterior  end  than  at  the  posterior.     On  the  other  hand,  a  very  large 

first  neural,  like  that  of  Jmyda  egregia,  may 
have  occupied  the  entire  space  between  the  first 
costals.  The  evident  relationship  of  this  species 
to  Asptderetes  coalescens  Cope,  as  figured  by 
Lambe  under  the  name  Trionyx  vagans,  renders 
the  presence  of  the  preneural  more  probable. 

Behind  the  preneural  there  were  7  neurals. 
These  had  the  usual  coffin-shape,  with  the  nar- 
rower ends  directed  forward,  except  the  sixth, 
which  is  oval  in  form,  and  the  seventh,  which 
has  the  broader  end  in  front.  The  neurals 
mostly  decrease  in  size  from  the  first  to  the  last. 
The  table  below  gives  the  dimensions  of  the  pre- 
neural and  the  neurals. 

The  first,  seventh,  and  eighth  costals  are 
considerably  broader  at  their  proximal,  than  at 
their  distal,  ends;  and  the  first  is  broadest  of 
all,  its  width  near  the  neural  being  88  mm. 
Distally  it  is  contracted  to  52  mm.  The  next 
three  costals  are  about  60  mm.  wide  near  the 
neurals,  the  second  and  the  fourth  about  no 
mm.  distally,  and  the  third  87  mm.  The  sixth 
and  seventh  costals  measure  about  50  mm.  each 
proximally,  while  distally  their  widths  are  respectively  108  mm.,  133  mm.,  and  25  mm.  The 
eighth  pair  meet  along  the  midline  for  a  distance  of  46  mm.  while  they  form  230  mm.  of  the 
hinder  border  of  the  carapace.  The  thickness  of  a  costal  at  its  sutural  border  and  in  the 
middle  of  the  length  is  10  mm.,  while  thru  the  rib  the  thickness  is  14  mm.  At  their  distal  ends 
the  costals  are  beveled  off  to  an  edge. 

The  ornamentation  consists  of  abrupt  and  narrow  ridges 
which  by  their  union  inclose  pits  and  furrows  of  irregular 
size  and  form.  There  are  usually  3  pits  or  furrows  in  a  dis- 
tance of  10  mm.;  but  in  places  there  may  be  only  2,  or  again, 
as  many  as  4.  They  are  largest  on  the  middle  of  the  lengths 
of  the  anterior  and  middle  costals  and  over  nearly  the  whole 
surface  of  the  hindermost  costals;  they  are  smallest  along 
the  middle  of  the  back  and  on  the  distal  ends  of  the  costals 
of  the  anterior  half  of  the  shell.  Toward  the  free  borders  of 
the  costals  the  pits  diminish  in  size,  and  finally  the  beveled 
border  is  left  nearly  smooth.  In  some  places  near  the  distal 
ends  of  the  costals  (plate  88,  fig.  8)  the  pits  are  nearly  quadrate  and  in  rows. 

On  plate  88,  fig.  7  shows  the  sculpture  on  the  outer  third  of  the  second  costal,  the  upper  end 
of  the  figure  being  the  more  anterior,  the  right  side  being  toward  the  middle  line  of  the 


Fig.  646. — Asptderetes  splendidus.     Carapace  of 
type.     X  it-    No.  3952  A.  M.  N.  H. 


Element. 

Length. 

Width. 

Preneural 

40? 

56? 

Neural  i 

57? 

56 

Neural  2 

60 

46 

Neural  3 

5^ 

4' 

Neural  4 

54 

4' 

Neural  5 

48 

42 

Neural  6 

4^ 

^9 

Neural  7 

33 

3> 

492  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

shell.  Fig  8  represents  the  outer  portion  of  the  fourth  left  costal,  the  figure  being  oriented  as 
in  fig.  7.  Fig.  9  presents  the  sculpture  on  the  proximal  half  of  the  third  left  costal,  the  upper 
end  being  toward  the  front  of  the  animal. 

This  species  differs  from  A .  beechen  in  being  more  deprest,  in  having  a  greater  proportion- 
ate width,  and  in  having  a  coarser  and  more  irregular  ornamentation.  From  Cope's  type  of 
Aspideretes?  vagans  it  seems  to  differ  in  having  a  coarser  sculpture.  From  A .  coalescens  Cope, 
as  exemplified  by  Lambe's  specimen  described  under  the  name  of  T .  vagans,  it  differs  in 
having  the  carapace  convex  in  front  and  in  the  different  form  of  the  nuchal  and  in  the  relatively 
greater  width;  likewise,  in  possessing  a  greater  number  of  neural  plates  and  much  larger 
eighth  costals. 

Aspideretes  beecheri  Hay. 
Plate  90,  fig.  2;    plate  92,  figs.  l,  2;    plate  96,  figs.  I,  2;    text-fig.  647. 

Trionyx  joveatus,  Baur,  I'roc.  Acad.  Nat.  Sci.  Phila.  1891,  p.  418. —  .'Marsh,  Monogr.  U.  S.  Geol.  Surv. 

xxvii,  1897,  p.  527. 
Aspideretes  beecheri,  Hay,  Amer.  Jour.  Sci.  (4),  xvill,  1 904,  p.  274,  plate  xvi;  Amer.  Geologist,  xxxv, 

1905,  P-  338- 

In  the  Marsh  collection  of  fossil  vertebrates  at  Yale  University,  there  is  a  finely  preserved 
specimen  of  a  trionychid  to  which  the  above  name  is  given.  It  was  collected  in  the  year  1889, 
by  Prof.  J.  B.  Hatcher  and  Dr.  C.  E.  Beecher,  in  the  Laramie  beds  of  Converse  County, 
Wyoming,  on  the  east  side  of  Lance  Creek.  It  is  named  in  honor  of  one  of  the  collectors. 
Dr.  C.  E.  Beecher,  formerly  professor  of  paleontology  in  Yale  University. 

This  specimen  was  studied  by  Dr.  G.  Baur  and  was  identified  by  him  as  Trionyx  foveatus 
of  Leidy.  The  present  writer  does  not  agree  with  this  identification.  Leidy's  species  was 
based  on  scant  materials,  but  the  ornamentation  of  the  costal  bones  is  characteristic  and  has 
led  to  the  identification  of  the  species  by  Mr.  L.  M.  Lambe  in  well-preserved  and  complete 
remains.    These  remains  indicate  a  very  different  trionychid  from  the  one  here  described. 

The  type  of  ^.  beecheri  presents  the  limbs  nearly  complete,  a  portion  of  the  neck,  the  tail, 
the  shoulder  and  pelvic  girdles,  a  large  portion  of  the  carapace,  and  the  whole  of  the  plastron. 
The  skull,  some  costals,  and  most  of  the  neurals  are  missing. 

The  carapace  (plate  92,  fig.  i)  was  nearly  as  broad  as  long,  the  length  being  close  to  323 
mm.;  the  width  310  mm.  It  was  apparently  rather  convex,  but  has  suffered  some  crushing 
during  fossilization.  The  front  of  the  shell,  along  the  nuchal,  was  nearly  straight,  but  at  the 
ends  of  this  bone  the  border  has  a  scallop  on  each  side.  The  lateral  borders  are  somewhat 
sinuous.    The  hinder  border  appears  to  have  been  excavated,  but  here  the  costals  are  wanting. 

The  nuchal  has  a  width  of  30  mm.  in  the  midline,  being  somewhat  notcht  for  the  reception 
of  the  preneural.  Its  outer  end  appears  to  project  slightly  over  the  first  costal  plate.  The 
preneural  is  of  hexagonal  form,  27  mm.  long  and  30  mm.  wide.  The  first  true  neural  is  hexag- 
onal, with  the  narrow  end  forward,  as  usual  in  the  species  of  this  family.  It  has  a  length  of 
32  mm.  and  a  width  of  21  mm.  The  second  neural  is  of  similar  shape,  42  mm.  long  and  26  mm. 
wide.  The  costals  display  nothing  characteristic.  There  were  probably  8  of  them.  The  ends 
of  the  costal  ribs  project  beyond  the  disk  about  17  mm.  anteriorly,  but  posteriorly  they  are 
longer,  that  of  the  seventh  being  about  50  mm.,  that  of  the  eighth  probably  about  70  mm. 
The  costals  are  about  5  mm.  thick  along  their  borders. 

The  sculpture  of  the  carapace  consists  of  a  network  of  ridges  inclosing  rather  deep  pits. 
Of  these  there  are  about  5  in  a  distance  of  10  mm.  Usually  they  are  without  definite  arrange- 
ment, but  toward  the  outer  ends  of  the  costals  they  dispose  themselves  in  rows  parallel  with  the 
margin  of  the  shell.  The  bottoms  of  the  pits  are  flat,  and  the  walls  rise  abruptly.  In  Aspideretes 
foveatus  the  pits  have  concave  bottoms  and  the  surrounding  walls  rise  gradually.  Often,  too, 
there  are  broad  smooth  spaces  between  the  pits  on  the  proximal  ends  of  the  costals  of  A . 
foveatus.  In  A.  beecheri  the  sutures  between  the  costals  resemble  seams  in  leather  sewed  with 
fine  stitches. 

The  plastron  is  complete.  The  entoplastron  is  slightly  notcht  in  front.  Its  lateral  limbs 
include  between  them  less  than  a  right  angle,  and  the  length  of  each  is  93  mm.,  measuring 
from  the  anterior  notch  of  the  body  of  the  bone.  The  epiplastra  are  broad  at  their  anterior 
ends.    They  resemble  much  those  of  Platypeltis  mutica.     The  hyoplastra  are  not  co-ossified 


TRIONYCHID^. 


493 


with  the  hypoplastra.  There  are  large  fontanels  in  the  midline  between  the  bones  just  men- 
tioned. The  hinder  of  these  fontanels  is  bounded  posteriorly  by  the  xiphiplastra.  The  latter 
bones  appear  to  have  met  along  the  midline  without  intervening  fontanel.  Where  narrowest 
the  bridge  is  64  mm.  wide. 

The  whole  lower  surface  of  the  hyoplastra,  hypoplastra,  and  the  xiphiplastra  is  covered 
with  a  sculpture  like  that  of  the  carapace,  except  that  it  is  finer. 

The  cervical  vertebra  seen  in  plate  92,  fig.  i,  is  probably  the  fifth.  Its  length  from  the 
front  of  the  prezygapophyses  to  the  hinder  end  of  the  postzygapophyses  is  64  mm. 

Seven  tail  vertebrae  are  present  in  a  series  122  mm.  long  but  there  were  others,  now  missing. 
The  most  anterior  appears  to  be  the  first.  These  vertebras  are  greatly  like  those  oi  Platypeltis 
spinifera^  but  the  ridge  representing  the  neural  spine  is  low  and  sharp  on  the  front  of  the 
vertebra.    Posteriorly  it  rises,  becomes  quite  rough,  and  reaches  a  width  of  5  mm.    From  the 

^_ _^        highest  point  it  descends  to  the  hinder  end  of  the  postzyga- 

/''  pophyses,  at  the  same  time  becoming  broader.  The  centrum 

of  the  first  caudal  has  a  length  of  20  mm.    The  sacral  verte- 
brae are  not  preserved. 

The  left  half  of  the  shoulder-girdle  is  exposed  to  view. 
It  resembles  that  of  other  Trionychidae.  The  distal  extremity 
of  the  coracoid  is  hidden  in  the  matrix.  The  procoracoid 
process  has  a  length  of  80  mm.  The  humerus  is  not  per- 
ceptibly different  from  that  of  P.  spinijera.  Its  length 
from  the  proximal  surface  of  the  head  to  the  distal  end  is 
95  mm.  The  ratio  of  the  length  of  the  bone  to  the  length 
of  the  carapace  is  about  the  same  as  in  the  living  species 
referred  to  above.  The  radius  has  a  length  of  44  mm. 
Neither  ulna  is  exposed  its  whole  length.  The  bones  of 
the  wrist  and  hand  are  somewhat  disturbed,  but  they 
appear  not  to  have  been  different  from  those  of  living 
members  of  the  family.  The  first  digit  is  strongly  developt 
and  ends  in  a  large  claw  phalanx.  The  claw  of  the  second 
digit  was  not  so  powerful. 

The  left  half  of  the  pelvis  is  represented  by  only  the 
anterior  portion  of  the  pubis  and  the  hinder  process  of  the 
ischium.  The  right  half  is  complete,  except  that  the  upper 
end  of  the  ilium  is  broken  off.  From  side  to  side  the  pubes 
measured  170  mm.  The  form  of  this  part  of  the  pelvis  is 
practically  that  oi  Platypeltis  sptntfera.  The  posterior  pro- 
cess of  the  ischium  is  not  so  flat  as  in  the  species  just  named. 
The  femur  appears  to  have  been  slightly  longer  relatively  to  the  shell  than  in  P.  spinifera. 
The  total  length  in  a  straight  line  is  no  mm.  The  tibia  is  67  mm.  long.  The  foot  presents 
nothing  distinctive. 

It  appears  probable  that  this  individual  was  a  male  well  advanced  in  age. 
The  i].  S.  National  Museum  possesses  a  specimen  which  appears  to  belong  to  A.  beecheri. 
This  also  was  collected  for  Prof.  O.  C.  Marsh  in  the  Laramie  deposits  of  Wyoming.     It 
bears  the  catalog  number  2358. 

There  is  no  part  of  the  plastron  present.  The  median  and  anterior  parts  of  the  nuchal  are 
wanting;  also  the  distal  extremities  of  the  first  three  costals  of  the  right  side;  large  parts  of  the 
distal  halves  of  the  costals  of  the  leftside;  and  the  free  extremities  of  all  the  ribs. 

The  carapace  (plate  90,  fig.  2;  text-fig.  647)  was  high  and  vaulted.  The  anterior  margin 
is  damaged.  The  posterior  margin  is  furnisht  with  a  wide  shallow  sinus.  The  total  length 
was  close  to  325  mm.;  the  breadth  was  almost  exactly  the  same;  the  height,  not  reckoning 
the  plastron,  was  about  80  mm. 

There  is  a  preneural  present,  but  its  anterior  end  is  eroded  away.  Behind  this  there  are  6 
neurals,  the  most  posterior  being  small  and  wedged  in  between  the  proximal  ends  of  the  costals 
of  the  sixth  pair.  The  anterior  4  have  the  usual  coffin-shape;  the  fifth  is  nearly  four-sided; 
the  sixth  is  oval.     The  table  on  page  494  gives  the  dimensions  of  the  preneural  and  neurals. 


Fig.  647. — Aspideretes  heecheri. 
Carapace.  X}.  No.  2358 
U.  S.  N.  M. 


494 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


Most  of  the  costals  are  widened  at  their  distal  ends.    The  costals  of  the  sixth  pair  join 
medially  without  interruption.    Those  of  the  eighth  pair  are  directed  backward,  and  join  for 

their  full  length  in  the  midline,  their  distal  ends  forming 
the  median  portion  of  the  border  of  the  shell.     The  free 


Element. 


Preneural . 

Neural  i . 
Neural  2.  , 
Neural  3 .  . 
Neural  4.  . 
Neural  5 .  . 
Neural  6. . 


Length. 

Width. 

i7± 

»3 

26 

^5 

36 

^3 

33 

^3 

33 

22 

28 

'5 

18 

10 

borders  of  the  median  costals  are  beveled  off  at  an  angle  of 


about  45°;  the  more  posterior  ones  are  rounded  on  the  edge. 
The  thickness  in  the  middle  of  their  length  is  usually 
close  to  6  mm.  at  the  sutures,  while  thru  the  rib  the  thick- 
ness amounts  to  8  mm.  At  their  distal  ends  the  thickness 
at  the  sutural  edges  is  lo  mm.  and  thru  the  rib  about  12 
mm.  The  ribs  are  quite  prominent  on  the  under  side  of 
the  costal  bones,  and  occupy  about  two-thirds  of  the  width 
of  the  plate.  Most  of  the  bodies  of  the  dorsal  vertebrae 
are  eroded  away,  and  there  is  exposed  a  cast  of  a  portion  of  the  neural  cord  about  5  mm.  in 
diameter  and  160  mm.  long. 

The  sculpture  (plate  q6,  fig.  2)  appears  to  agree  well  with  that  of  the  type  of  this  species; 
but  it  has  suffered  somewhat  from  weathering.  On  the  middle  of  the  costals  there  are  4  or  5 
pits  in  10  mm.  On  the  neurals  and  the  distal  ends  of  the  costals  they  are  somewhat  smaller; 
on  the  nuchal  and  in  places  on  the  hindermost  pair  of  costals,  somewhat  larger. 

This  specimen  reveals  to  us  the  convexity  of  the  carapace,  as  well  as  the  form  of  the  hinder 
border. 

Two  carapaces  have  been  submitted  to  me  for  examination,  which  had  been  collected  by 
Prof.  J.  B.  Hatcher  in  the  Judith  River  beds  on  Fish  Creek,  Montana.  These  bear  the 
numbers  445  and  541  of  the  Carnegie  Museum,  Pittsburg.  No  characters  are  observed  which 
serve  to  distinguish  these  carapaces  from  that  of  the  type  of  A.  beecheri.  It  is  not  improbable, 
however,  that  they  belong  to  a  distinct  species. 

Prof.  O.  C.  Marsh,  as  cited  in  the  synonymy,  has  reported  Trtonyx  foveatus  from  the 
Ceratops  beds  near  Denver,  Colorado.  The  writer  does  not  know  on  what  the  determination 
was  based;  but  it  appears  probable  that  the  specimens  belonged  to  A .  beecheri. 


Aspideretes  iontanus  sp.  nov. 
TeTt-fig.  648. 

From  the  Laramie  beds  at  Ojo  Alamo,  San  Juan  County,  New  Mexico,  Mr.  Barnum 
Brown,  of  the  American  Museum  of  Natural  History,  in  1904,  brought  materials  belonging 

apparently  to  3  species  of  the 
genus  Aspideretes.  Of  these  the 
present  is  represented  by  nearly 
the  whole  of  the  right  half  of  the 
nuchal  and  a  considerable  part  of 
the  right  first  costal.  The  number 
of  the  specimen  is  6070. 

At  no  point  does  this  piece  of 
nuchal  come  to  the  midline;  hence 
we  can  not  determine  the  exact 
extent  of  the  bone  laterally.  It 
was,  however,  not  far  from  260 
mm.  The  animal  was  therefore 
one  of  considerable  size.  The 
inner  hinder  angle  of  the  bone 
presents  a  part  of  the  sutural  bor- 
der for  the  preneural,  and  from 
this  to  the  outer  end  of  the  nuchal 
is  125  mm.  Thewidth  of  the  bone, 
where  it  came  into  contact  with  the  preneural,  is  60  mm.  The  anterior  border  is  not  beveled, 
but  is  cut  off  nearly  at  right  angles  with  the  upper  surface.    The  greatest  thickness,  thru 


Fig.  648. 


-Aspideretes  fontanus.    X  5.     Part  of  nuchal  and  part 
of  first  right  costal  of  type. 


TRIONYCHID^. 


495 


the  ridge  on  the  lower  surface,  is  i6  mm.  Where  it  made  contact  with  the  preneural  the 
thickness  is  only  4  mm. 

The  portion  of  the  costal,  the  proximal  half,  almost  certainly  belongs  to  the  same  indi- 
vidual. At  its  proximal  end  it  presents  the  sutural  borders  for  the  preneural  and  the  first 
neural.  Evidently  the  preneural  was  somewhat  wider  than  the  neural.  Its  length  was  at  least 
40  mm.  The  border  of  the  costal  for  union  with  the  neural  is  7  mm.  thick.  About  the  middle 
of  the  length  of  the  hinder  border  of  the  costal  the  thickness  is  7  mm. 

The  upper  surface  of  the  bone  is  incrusted  with  a  layer  of  iron  oxide;  but  so  far  as  can 
be  discovered  the  sculpture  was  finer  than  in  the  other  two  species  found  in  that  region, 
A .  austerus  and  /I.  vorax.    The  few  pits  observed  appear  to  be  about  2.5  mm.  in  diameter. 

The  respects  in  which  this  species  diiFers  from  those  just  named  are  mentioned  under 
their  respective  descriptions. 

Aspideretes  austerus  sp.  nov. 
Teit-figs.  649,  650. 

The  fragmentary  specimen  on  which  the  present  species  is  based  was  collected  in  1904, 
by  Mr.  Barnum  Brown,  from  Laramie  deposits  at  Ojo  Alamo,  San  Juan  County,  New  Mexico. 
The  catalog  number  of  the  specimen  is  6068.  The  remains,  belonging  apparently  to  a  single 
individual,  consist  of  the  nuchal  except  the  central  portion,  part  of  both  first  costals,  the 
greater  part  of  a  right  posterior  costal,  probably  the  sixth,  various  fragments  of  costals,  a 
piece  furnishing  parts  of  two  neurals,  and  a  considerable  portion  of  the  right  hypoplastron. 

The  species  is  characterized  by  the  very  thick  bones  and  the  coarse  sculpture  of  both 
the  carapace  and  the  plastron. 


Fig.  649. — Aspideretes  austerus.     X  5.     Parts  of  nuchal  and  first  costals  of  typi'- 

On  account  of  the  missing  middle  region  of  the  nuchal,  the  exact  lateral  extent  of  this  bone 
can  not  be  determined.  It  was,  however,  not  far  from  230  mm.,  being  thus  somewhat  less  than 
that  o(  A.  fontanus,  just  described.  The  greatest  width  is  45  mm.,  a  fourth  less  than  that  of  A. 
fontanus.  The  greatest  thickness  of  the  bone  is  21  mm.  The  free  anterior  border  is  not  bev- 
eled, but  is  cut  off  at  nearly  right  angles  with  the  upper  surface,  like  that  of  the  species  just 
mentioned.  The  thickness  of  this  border  varies  from  10  mm.  toward  the  midline  to  15  mm. 
near  the  outer  end. 

The  first  costal  is  about  72  mm.  wide  near  the  neural  border  and  it  increases  to  80  mm. 
near  the  distal  end.  The  free  border  is  cut  off  at  a  nearly  right  angle  to  the  upper  surface. 
The  thickness  of  this  border  is  10  mm.  or  more.  The  hinder  border  of  this  bone  is  10  mm. 
thick. 

The  posterior,  probably  the  sixth,  costal  is  25  mm.  wide  1 10  mm.  from  the  distal  end,  but 
it  widens  rapidly  to  55  mm.  The  free  border  is  like  that  of  the  first  costal.  There  must  have 
been  a  considerable  notch  between  this  costal  and  the  one  next  behind.  In  thickness  this 
costal  ranges  between  9  mm.  near  the  proximal  end  and  10  mm.  at  the  distal  end. 


496 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


The  sculpture  of  the  carapace  is  best  displayed  toward  the  free  borders.  It  consists  of 
abruptly  sunken  pits,  of  which  there  are  usually  5  in  a  line  20  mm.  long.  Closer  to  the  free 
borders  the  pits  are  smaller.     Nowhere  does  there  appear  any  tendency  for  the  formation  of 

straight  rows  of  pits,  such  as 
are  seen  on  the  costals  of 
]  Amyda  cariosa,  of  the  New 
Mexico  Wasatch.  On  the  por- 
tions of  the  carapace  near  the 
midline  the  pits  are  less  con- 
spicuous. They  appear  to  be 
as  large,  but  the  walls  appear 
worn  down. 

The  hypoplastron  (fig.  650) 
is  thick    and    heavy.     At   the 

„       ,  J     ■,  V      IT  1     1'         1  r  suture  with  the    hvoplastron, 

riG.  0<;o. — Asptderetes  austerus.     X  5.     Kieht  hypoplastron  of  type.  r       r  1  •  ii-  1 

-^'^  oyrr  jr        not  tat  irom  the  midnne,  the 

thickness  is  13  mm.    One  border  of  the  notch  for  the  process  of  the  xiphiplastron  remains. 

This  bone  was  articulated  with  the  hypoplastron  by  a  jagged  suture  and  it  must  have  extended 

anteriorly  near  the  midline.     The  outer  end  of  the  hypoplastron,  near  the  bases  of  the  lateral 

processes,  is  16  mm.  thick. 

Evidently  nearly  the  whole  lower  surface  of  the  plastron  was  covered  by  the  sculptured 
layer.  The  pits  are  smaller  than  those  of  the  carapace,  there  being  about  7  pits  in  a  line  20  mm. 
long.    Many  of  them  coalesce  to  form  winding  furrows. 

This  species  differs  from  A.  fontanus  in  having  a  narrower  nuchal,  much  thicker  bones, 
and  a  considerably  coarser  sculpture.    It  is  referred  to  Asptderetes  provisionally. 

Aspideretes  vorax  sp.  nov. 

Text-fig.  651. 

This  species  was  collected  from  the  Laramie  deposits  near  Ojo  Alamo,  San  Juan  County, 
New  Mexico,  in  1904,  by  Mr.  Barnum  Brown.  The  type  is  in  the  American  Museum  of  Nat- 
ural History  and  has  the  catalog  number  6140.  The  species  is  represented,  as  far  as  known, 
by  only  the  nuchal  bone;  but  this  is  complete.  The  length  of  the  bone,  from  side  to  side,  is 
200  mm.  in  a  straight  line,  215  mm.  over  the  curve.  The  lateral  convexity  is  considerable  and 
appears  to  have  been  somewhat  greater  than  that  of  either  A .  austerus  or  A .  fontanus,  both 
from  the  same  locality  as  this  species.    The  width  at  the  midline  is  45  mm.,  the  greatest  width, 

55  mm.  The  greatest  thickness  is 
15  mm.  There  is  a  moderatemedian 
sinus  in  the  anterior  border.  This 
border  is  not  dipt  off  at  a  nearly 
right  angle  with  the  upper  surface  as 
in  the  two  other  species  mentioned 
above;  but  is  beveled  down  on  the 
upper  surface  of  the  bone  to  a  sharp 
edge.  This  beveled  surface  is  not 
sculptured.  The  hinder  border  of  the  bone  presents  a  median  excavation,  for  the  preneural 
bone.  The  latter  bone  was  evidently  unusually  broad,  the  excavation  having  a  width  of  at 
least  55  mm.  The  preneural  border  is  thicker  than  that  of  A.  fontanus,  the  thickness 
being  7  mm. 

The  sculpture  of  the  bone  is  obscured  by  a  layer  of  hard  matrix;  but  so  far  as  can  be 
determined,  it  was  intermediate  between  A.  fontanus  and  A.  austerus,  approaching  more 
closely  the  latter. 

Certain  fragments  of  costals  present  probably  belong  to  this  species,  but  possibly  to  A . 
fontanus.  One  of  these,  apparently  the  right  sixth,  is  35  mm.  wide  at  the  neural  border, 
30  mm.  wide  more  distally,  and  has  a  thickness  of  8  mm. 

This  species  differs  from  A.  fontanus  in  having  the  free  anterior  border  of  the  nuchal 
beveled,  the  bone  thicker  at  the  preneural  border,  and  a  coarser  sculpture.    From  A,  austerus 


Fig.  651. — Aspideretes  vorax.     X  §.    Nuchal  bone  of  type. 


TRIONYCHID^.  497 

it  differs  in  having  a  nuchal  with  greater  antero-posterior  width,  the  bone  not  so  thick,  and 
with  the  free  anterior  border  beveled  off,  instead  of  being  dipt  off  at  a  right  angle  with  the 
upper  surface. 

.   Aspideretes?  vagans  (Cope). 
Plate  96,  fig.  3. 

Trionyx  vagans,  CoPE,  Ann.  Report  U.  S.  Geo!,  and  Geog.  Surv.  Colorado,  1873  (1874),  p.  45^;  Bull. 
U.  S.  Geol.  and  Geog.  Surv.  Terrs.,  i.  No.  2,  1874,  p.  29;  Vert.  Cret.  Form.  West,  1875,  pp.  96,  260, 
plate  vi,  fig.  13. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  454. — Hatcher,  Bull.  U.  S. 
Geol.  Surv.  No.  257,  1905,  p.  73. 

The  type  of  this  species  is  a  fragment  of  a  costal  plate,  which  was  collected  by  Professor 
Cope  in  1873,  from  what  have  usually  been  regarded  as  Laramie  deposits  in  Colorado.  From 
Whitman  Cross  (Monogr.  U.  S.  Geol.  Surv.,  xxvii,  1896,  p.  244)  we  learn  that  the  more  exact 
locality  is  on  Bijou  Creek,  40  miles  east  of  Denver.  Mr.  Cross  believes  that  the  deposits  belong 
to  the  Arapahoe  beds,  of  the  Post-Laramie. 

The  type  fragment  has  a  length  of  50  mm.,  a  width  of  37  mm.,  a  thickness  at  the  sutural 
borders  of  5  mm.,  and  thru  the  rib,  of  6  mm.  It  was  figured  by  Cope  in  1875,  as  cited. 
Another  figure  of  it  is  presented  on  plate  96,  fig.  3.  This  specimen  is  now  in  the  American 
Museum  of  Natural  History  and  has  the  number  1847.  The  other  fragment  figured  by  Cope  at 
the  same  time  has  been  lost.  Still  other  fragments  were  mentioned  in  the  original  description, 
but  were  not  described  and  they  have  now  disappeared. 

It  is  to  be  remarkt  of  Cope's  figure  of  the  type  specimen  that  it  brings  out  the  ridges  into 
too  great  contrast  with  the  pits.  The  latter  are  really  very  shallow,  and  they  rise  gradually 
from  the  bottom  to  the  summits  of  the  surrounding  walls.  For  this  reason  Hatcher's  remarks 
(op.  cit.  p.  74)  regarding  Lambe's  Judith  River  form  are  not  pertinent. 

Various  specimens  from  Montana,  Wyoming,  and  Canada  have  been  referred  to  this 
species;  but  after  careful  comparison,  the  writer  has  come  to  the  conclusion  that  it  is  impossible 
to  identify  any  of  them  with  Cope's  type.  It  seems  best,  therefore,  to  describe  and  name 
specimens  from  other  localities  without  regard  to  it,  until  better  materials  have  been  collected 
in  the  type  locality. 

Whether  or  not  the  fragmentary  materials  which  Cope  has  referred  to  this  species  from 
near  the  mouth  of  the  Big  Horn  River,  in  Montana,  from  the  Judith  River  beds,  from  North 
Dakota,  and  from  the  Milk  River  region  of  British  America,  belong  to  it  is  extremely  doubt- 
ful. Some  of  them  probably  belong  to  the  species  here  described  as  A.  splendidus  Hay,  A. 
beechert  Hay,  and  A .  coalescens  Cope. 

It  is  to  be  noted  that  in  the  Vertebrata  of  the  Cretaceous  Formations  of  the  West,  Cope 
states  that  there  are  4  or  5  pits  in  19  mm.  This  is  evidently  a  typographical  error;  for  in  the 
original  description  there  are  said  to  be  4  or  5  pits  in  10  mm.,  which  is  correct. 

Aspideretes  sagatus  sp.  nov. 
Plate  93,  figs.  1-3;   text-fig.  652. 

This  species  is  represented  in  the  collection  of  the  American  Museum  of  Natural  History 
by  a  complete  carapace.  It  was  collected  in  the  year  1892,  in  the  Puerco  deposits  of  New 
Mexico.     The  catalog  number  is  1201. 

This  carapace  (plate  93,  fig.  i ;  text-fig.  652)  is  approximately  circular  in  form,  having  a 
length  of  375  mm.  and  an  extreme  breadth  of  312  mm.,  exclusive  of  the  projection  of  the  rib- 
ends  beyond  the  margin  of  the  shell.  The  front  margin  of  the  nuchal  plate,  in  the  midline,  is 
slightly  concave.  Behind,  the  shell  is  narrowly  truncate.  Transversely  the  shell  was  moder- 
ately convex,  less  so  longitudinally.  All  around  the  margin  the  carapace  is  beveled  off  rather 
abruptly,  and  concavely,  so  as  to  produce  a  broad  shallow  groove.  Nowhere  does  the  sculp- 
tured layer  overhang  the  free  portions  of  the  ribs  or  the  deeper  layers  of  bone.  The  bone  has 
a  thickness  of  about  9  mm.  It  is  somewhat  thicker  in  the  middle  of  the  width  of  the  costal 
plate,  but  not  much.    The. costal  plates  also  grow  slightly  thicker  toward  their  free  margins. 

There  are  2  plates  between  the  proximal  ends  of  the  first  pair  of  costal  plates,  a  preneural 
and  a  neural.  The  preneural  is  a  trapezoid,  whose  broadest  side,  50  mm.,  articulates  with  the 
nuchal,  while  its  shortest  side,  22  mm.,  joins  the  first  neural.    The  median  length  is  29  mm. 

32 


498 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


1 

Neural. 

Median 
length . 

Greatest 

width. 

I 

34 

15 

2 

37 

H 

3 

33 

^3 

4 

3» 

22 

5 

3° 

l6 

6 

20 

9 

The  first  neural  is  hexagonal  with  the  long  sides  parallel.  The 
second,  third,  fourth  and  fifth  neurals  are  coffin-shaped;  the 
sixth  neural  is  pentagonal  and  pointed  behind.  The  table  here- 
with gives  the  dimensions  of  the  neurals. 

The  nuchal  is  firmly  joined  by  its  whole  posterior  border  to 
the  first  costal  plates  and  to  the  preneural.  Its  antero-posterior 
length  is  38  mm.;  its  width  from  side  to  side  is  close  to  154  mm. 
Its  whole  upper  surface,  with  the  exception  of  the  beveled  edge, 
is  covered  with  the  ridges  and  pits  of  the  ornamentation.  It  is 
therefore  in  form,  in  extent  of  articulation,  and  ornamentation 
extremely  different  from  the  nuchal  of  T.  puercensts. 

The  eighth  pair  of  costals  together  form  about  125  mm.  of  the  hinder  margin;  fore  and 
aft  in  the  middle  line  they  measure  38  mm. 

The  sculpture  (plate  93,  figs.  2,  3)  consists  of  a  coarse  network  of  ridges  which  inosculate 

somewhat  irregularly  and  inclose  deep  pits  of  varying  sizes. 
The  sculpture  is  coarsest  on  the  distal  third  of  the  costal 
plates,  where  there  are  about  5  pits  in  a  line  25  mm.  long; 
and  here  there  is  a  tendency  toward  an  arrangement  of  the 
stronger  ridges  across  the  costal  plates.  Nearer  the  midline 
of  the  shell  there  will  be  found  about  6  or  7  pits  in  this  distance. 
Near  the  free  margins  of  the  costal  plates  there  is  a  tendency 
for  the  ridges  to  break  up  into  tubercles  having  elongated  or 
circular  bases.  It  might  be  difficult  in  some  cases  to  distin- 
guish fragments  of  the  shell  oiT .  puercensts  bearing  its  coarser 
sculpture,  from  fragments  of  the  present  species  bearing  the 
finer  ornamentation.  If  they  are  marginal  pieces  the  species 
may  be  determined  usually  from  the  fact  that  the  margin  of 
P.  puercensts  is  beveled  off  less  abruptly  and  with  a  plane  or 
convex  surface,  while  that  of  P.  sagatus  has  the  bevel  abrupt 
and  often  slightly  concave. 

This  species  resembles  in  many  ways  those  figured  by 
Professor  Cope  on  plate  xxvi  of  his  Extinct  Vertebrata 
obtained  in  New  Mexico  (Wheeler  Survey  West  looth  Merid- 
ian, vol.  iv).  A .  sagatus,  however,  differs  from  T .  leptomitus 
and  T .  cartosus  in  not  having  the  sculptured  layer  of  bone 
overhanging  the  supporting  layers  at  the  outer  ends  of  the 
costal  plates;  likewise,  in  not  having  the  ridges  of  the  sculpture  arranged  in  lines  parallel  with 
the  length  of  the  shell. 

Aspideretes  ?  nassau  sp.  nov. 

Text-fig.  653. 

The  only  known  specimen  of  this  species  was  collected  by  Dr.  Marcus  S.  Farr,  of  Princeton 
University,  Princeton,  New  Jersey,  in  Fort  Union  deposits,  at  Duffy's  ranch,  18  miles  from 
Melville,  Sweet  Grass  County,  Montana.  The  specimen  belongs  to  the  university  named. 
Only  the  carapace  (fig.  653)  is  represented. 

The  nuchal  bone,  all  of  both  first  costals  except  a  small  part  of  the  one  of  the  right  side, 
and  the  first  and  second  neurals  are  missing.  It  is  assumed  that  this  species,  like  those  from 
the  approximately  equivalent  Puerco  deposits,  possest  a  preneural  bone  and  belonged,  there- 
fore, to  the  genus  Asptderetes.     There  were  certainly  8  pairs  of  costals  and  7  neurals. 

The  individual  here  described  was  evidently  an  aged  one,  since  the  disk  extended  out  to 
the  ends  of  the  ribs.  The  species  was  a  small  one.  The  length  can  not  be  exactly  determined, 
but  was  approximately  195  mm.  The  width,  in  a  straight  line,  is  200  mm.  The  rear  of  the 
carapace  is  truncated,  more  exactly,  slightly  concave  in  outline.  The  upper  surface  is  convex 
from  front  to  back,  more  strongly  so  from  side  to  side.  The  free  borders  are  cut  off  nearly 
perpendicularly  to  the  upper  surface  and  are  about  9  mm.  thick.  Toward  their  proximal  ends 
the  costals  are  reduced  in  thickness  to  5  mm. 


Fig.  652. — Aspideretes   sagatus. 
Carapace  of  type.     X  1. 


TRIONYCHID^. 


499 


The  neuials  are  relatively  broad.     The  accompanying  table  shows  their  dimensions. 

It  is  not  certain  that  the  outlines  of 
the  seventh  neural  are  correctly  drawn  in 
the  figure;  but  they  appear  to  be  as  shown. 
If  so,  this  neural  is  of  unusual  form  and  size 
for  the  posterior  one.  It  did  not  wholly 
separate  the  costals  of  the  seventh  pair  at 
the  midline. 


Neural. 

Length. 

Width. 

3 
4 

s 

6 

lo 

■7 
■5 

"9 
18 

'5 
•3 

The  central  portions  of  the  upper  sur- 
face of  the  carapace  are  nearly  smooth. 
Gradually  toward  the  outer  borders  a 
sculpture  appears.  On  a  band  about  35 
mm.  wide  around  the  borders  this  sculp- 
ture is  quite  distinct  and  consists  of  ridges 
separated  by  furrows  and  pits.  These 
ridges  run  nearly  parallel  with  the  free  bor- 
ders of  the  carapace.  The  furrows  are  usually  narrower  than  the  flat-topped  ridges.  A  line 
10  mm.  long  crosses  four  of  the  ridges. 

Nassau,  an  old  name  for  Princeton  University. 


Fig.  653. — Jspi,i\ 
Xo.35- 


w;».     Carapace  of  type. 
Partly  restored. 


Aspideretes  puercensis  sp.  nov. 
Plate  94,  figs.  1-3;    plate  104,  figs,  z,  3;   text-figs.  654,  655. 

This  species  is  represented  by  a  single  specimen,  which  belongs  to  the  American  Museum 
of  Natural  History,  and  bears  the  number  1202.    The  right  side  of  the  carapace  is  nearly  com- 

^,--p      cs.  plete,  lacking  only  the  eighth 

j"  >,-T  '''i,5S§'^\  costal   and  the  free  ends  of 

"'     /  "'    V^^    \  .  -'''P  most  of  the  ribs;  and  there 

I     ~'-^'' ^rv'  ^'^  present  large  portions  of 

-7  A~^~--~_      _--U  ^^^  '^^'  ^''^^  °^  ^^^  plastron. 

\  .,,-j  V~~-  ^"  tlicse  parts  belonged  to  a 

■-JZ — t^  ^ — =:::j;_^_j».,^v,^      single  individual,  which  was 

—  \>5.  ^  collected  by  Dr.  J.  W.  Wort- 

.--'^  --..  J^^^^f/  man  and  Mr.  O.  A.  Peterson, 

/-""*-    Q    ^y  '"  '892,  in  the  Puerco  beds 

--,,    I       J     V/^  of  New  Mexico,  probably  in 

--'''  -^^  / ^  ^^'  the    southern    part    of    Rio 

Arriba  County. 

Up  to  the  present  time,  no 

Figs.  654  and  b^'^.—Aspideretes       species  of  Trionychidae  has 

puercensis.     X  i.  been     described     from     the 

\  ,      ^  ,      „,  Puerco  Eocene  except  Con- 

---'  054.  Carapace.  655.  Plastron.  ,       ,    ,  ,      .      ,  ...'^      .- 

chocnelys    admtrabtlis    Hay. 

\_>,       --.^s  654.  Professor  Cope  has  credited 

(Proc.  Amer.    Philos.    Soc, 

XX,  p.  461)  to  the  Puerco  deposits  the  Wasatch  species  Plastomenus  communis,  but  it  was 

with  a  doubt,  and  the  species  was  not  included  in  later  lists.   Nor  is  it  mentioned  in  Cope's 

Vertebrata  of  the  Tertiary  Formations  of  the  West  as  belonging  to  the  Puerco. 


500 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


The  carapace  (plate  94,  fig.  i)  of  the  type  of  this  species  had  a  length  of  330  mm.  and  a 
breadth  of  263  mm.,  not  including  the  extension  of  the  ribs  beyond  the  costal  plates.  If  we 
include  the  ribs,  the  width  was  at  least  as  great  as  the  length. 

The  nuchal  is  a  considerable  bone,  having  had  an  extension  from  side  to  side  of  about 
175  mm.,  and  a  width  of  about  35  mm.  at  the  midline.  Anteriorly  it  is  somewhat  excavated, 
while  posteriorly  it  is  articulated  with  the  preneural.  It  was  not  in  contact  with  the  anterior 
costal  plates,  but  its  distal  extremity  probably  overlapt  the  distal  end  of  the  rib  of  the  first 
costal.  The  connection  of  the  nuchal  with  the  bones  behind  it  was,  therefore,  a  rather  loose 
one.  In  Bell's  Monograph  of  the  Testudinata  there  is  a  figure  (plate  liv)  of  Trionyx  labiatus 
{Testudo  triunguis  Forskal)  which  shows  a  nuchal  much  like  that  of  the  fossil  species 
here  described.  The  living  species  differs,  however,  from  A .  pucrcensis  in  not  having  the 
nuchal  articulated  to  either  a  costal  plate  or  a  median  bone,  only  overlapping  the  ends  of  the 
ribs  projecting  from  the  first  costal  plates. 

The  nuchal  of//,  puercensis  is  thin,  except  for  a  rib-like  thickening  which  follows  the  length 
of  the  bone  on  the  lower  side.  The  lateral  wings  terminated  in  digitations.  On  the  upper  side 
the  bone  is  smooth  and  was  covered  with  soft  tissue,  except  a  patch  in  the  midline,  48  mm. 
from  side  to  side  and  25  mm.  fore  and  aft.    This  has  the  sculptured  surface  found  elsewhere 


Element.             Length. 

Width. 

Preneural 

Neural   i 

Neural  2 

Neural  3 

Neural  4 

Neural  5 

Neural  6 

Neural  7 

28 
40 
39 

w 

34 
28 
28 

50. 
3° 
30 
28 

J7 
^5 
18 

'S 

on  the  carapace.  Around  this  area, 
on  the  sides  and  behind,  the  bone 
is  beveled  off  in  continuation  with 
the  beveling  of  the  edge  of  the  rest 
of  the  carapace. 

Between  the  proximal  ends  of 
the  first  costals  we  find  2  bones,  a 
preneural  and  the  first  neural. 
The  former  is  irregularly  penta- 
gonal, with  the  broadest  side  artic- 
ulating with  the  nuchal.  The  two 
shortest  sides  lie  in  a  notch  of  the 
first  neural.  The  anterior  5 neurals 
are  elongated  hexagonal,  with  the 


Fig.  656. — Aspideretes  singularis.     X  i-     Carapace  of  type. 


broadest  end  directed  posteriorly.  The  next  neural  is  quadrilateral,  while  the  last  is  nearly 
triangular.  The  dimensions  of  the  preneural  and  the  neurals  are  given  in  the  table. 

The  first  costal  is  the  broadest  of  all.  In  front  and  laterally  it  is  beveled  off  from  the 
sculptured  layer  to  the  inner  surface.  Medially  it  articulates  with  the  preneural  and  with  the 
long  side  of  the  first  neural.    The  width  of  the  succeeding  costals  diminishes  toward  the  rear. 

The  thickness  of  the  costals  is  pretty  uniformly  7  mm.  near  the  sutural  borders,  and  9  mm. 
thru  the  rib.  The  latter  extended  beyond  the  edge  of  the  costal  plates  for  a  considerable 
distance;  in  the  case  of  the  rib  of  the  second  costal,  somewhat  more  than  50  mm.  The  ribs 
are  broad,  occupying  about  half  the  width  of  the  costal  plates. 

Of  the  plastron  (plate  104,  figs  2,3;  text-fig.  655)  there  are  present  the  left  hyoplastron, 
the  left  hypoplastron,  and  part  of  the  right  xiphiplastron.  These  elements  do  not  differ  in  any 
important  respect  from  the  same  bones  in  living  Trionychidae.  Altho  they  are  quite  thick, 
they  are  not  unusually  large.  The  width  of  the  hyoplastron  and  the  hypoplastron  taken 
together,  measured  across  the  narrowest  part,  is  55  mm.;  and  of  this  width  each  occupies  one- 


TRIONYCHID^. 


501 


half.  Toward  the  midline  the  hypoplastron  becomes  much  wider  than  the  hyoplastron. 
The  hypoplastron  sends  inward  a  finger-like  process,  which  no  doubt  joined  a  similar  process 
from  the  bone  of  the  opposite  side.  The  median  border  of  both  bones  was  very  obliquely 
beveled.  The  greatest  thickness  of  the  hypoplastron  is  12  mm.  The  xiphiplastron  present 
appears  to  belong  to  the  right  side.  It  has  a  central,  thick  portion,  sculptured,  oval,  25  mm. 
wide,  and  about  40  mm.  long.  This  passes  by  a  bevel  into  the  thinner  portion  on  all  sides.  The 
thinner  part  extended  forward  into  digitations  joining  the  hypoplastron,  and  posteriorly  into 
others  which  connected  with  the  corresponding  bone  of  the  opposite  side.  It  is  evident  that 
there  were  large  fontanels  between  the  right  and  left  halves  of  the  plastron. 

The  sculpture  (plate  94,  figs.  1-3)  consists  of  a  network  of  ridges  which  inclose  pits  of 
rather  regular  form  and  size.  The  pits  are  of  somewhat  greater  diameter  than  the  ridges  sur- 
rounding them.  On  the  neurals  there  are  about  5  pits  in  12  mm.,  while  on  the  hindermost 
costals  there  are  only  about  3  in  the  same  distance.  The  pits  increase  somewhat  in  size  from  the 
proximal  toward  the  distal  ends  of  the  costals.  There  is  no  tendency,  near  the  free  margins 
of  the  costals,  toward  either  the  disappearance  of  the  ridges  or  toward  their  breaking  up  into 
tubercles.     There  are  no  welts  on  the  surface  such  as  we  find   in  species  of  Plastomenus. 

The  sculpture  of  the  plastron  is  greatly  like  that  of  the  carapace.  The  sculptured  part  of 
the.  hyoplastron  is  nowhere  more  than  30  mm.  wide,  while  that  of  the  hypoplastron  is  53  mm. 


Aspideretes  singularis  sp.  nov. 
Figs.  656—662. 

The  type  of  this  species  is  a  nearly  complete  specimen  which  was  collected  for  Prof. 
E.  D.  Cope,  by  Mr.  David  Baldwin,  in  1883,  from  the  Torrejon  beds  of  Chaco  Canyon,  San 
Juan  County,  New  Mexico.  It  furnishes  the  oldest-known  trionychid  skull  that  is  accom- 
panied by  the  shell. 
Conchochelys  admtra- 
bilis,  of  the  underlying 
Puerco  beds,  furnishes 
an  older  skull,  but  the 
shell  is  entirely  un- 
known. 

The  carapace  (fig. 
656)  must  have  been 
rather  convex,  but  the 
convexity  was  probably 
increast  during  fossili- 
zation.  The  length  is 
350  mm.  The  width  of 
the  disk  could  not  have 
exceeded  280  mm.  Be- 
yond this  the  rib-ends 
extend  50  mm.  on  each 
side.  Therefore  the 
whole  width  of  the 
carapace  was  about 
380  mm.  It  is  com- 
posed of  the  nuchal,  a 
preneural,  7  neurals 
and  8  pairs  of  costals. 
The  nuchal  extends 
from  side  to  side  190 

mm.;  fore  and  aft,  37  mm.  The  outer  ends  of  the  bone  are  smooth,  the  central  portion  is 
pitted.  The  free  borders  of  the  carapace  are  beveled  and  smooth,  but  the  general  surface 
is  carved  into  ridges  and  inclosed  pits.  On  the  neurals  and  adjoining  parts  of  the  costals 
the  pits  are  nearly  circular  and  there  are  3  or  4  of  them  in  a  line  20  mm.  long.    Distally  the 


Fig.  657. — Aspideretes  singularis.      Plastron. 


Xi 


502 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


pits  are  larger.  On  the  outer  ends  of  the  costals  the  pits  are  mostly  in  rows  and  there  are  only 
three  or  four  in  a  line  of  the  length  given. 

All  the  parts  of  the  plastron  (fig.  657)  are  present.  The  limbs  of  the  entoplastron  are  112 
mm.  long.  The  epiplastra  are  18  mm.  broad  anteriorly  and  about  100  mm.  long.  The  hyohy- 
poplastral  suture  is  143  mm.  long.  The  bridge  is  56  mm.  wide.  Each  xiphiplastron  is  no 
mm.  long  and  75  mm.  wide.     The  sculpture  of  the  plastron  is  finer  than  that  of  the  carapace. 

The  skull  (figs.  658-660)  is  complete  and  little  distorted.  It  resembles  closely  that  of 
Platypeltis  ferox,  but  the  profile  descends  more  abruptly  from  the  middle  of  the  orbits.  The 
length  from  snout  to  occipital  condyle  is  102  mm.  From  the  outside  of  one  quadrate  to  that 
of  the  other  is  67  mm.    The  orbits  are  large,  the  diameter  being  20  mm.    The  roof  of  the  mouth 


662. 


Figs.  658-662. — Aspideretes  singularis.     Parts  of  type.     X^. 


660.  Right  side  of  skull.  66i.  Fore  leg.  662.  Hind  leg. 

is  mostly  concealed  by  the  bones  of  the  tongue.  It  is  seen,  however,  that  the  choanae  are  placed 
25  mm.  behind  the  tip  of  the  snout.  The  shoulder-girdle  and  bones  of  the  foreleg  (fig.  661) 
differ  little  from  those  of  the  living  species  just  mentioned.  One  forefoot  is  nearly  complete. 
The  pelvis  and  hinder  limbs  (fig.  662)  offer  no  peculiarities.  The  bones  of  the  hinderfeet 
are  not  completely  preserved. 

The  sculpture  of  this  species  resembles  that  of//,  sagatus  and  A.  puercensis.  From  the 
former  it  differs  in  having  a  larger  portion  of  the  nuchal  bone  devoid  of  sculpture  and  in  having 
this  bone  extend  much  farther  across  the  outer  end  of  the  first  costal.  From  A.  puercensis  it 
differs  in  having  the  nuchal  more  closely  joined  to  the  first  costals  and  a  coarser  sculpture 
on  the  outer  ends  of  the  costals.     There  are  differences  in  the  plastra  of  the  two  species. 


trionychidj^.  503 

Aspideretes  ?  guttatus  (Leidy). 
Text-figs.  663,  664. 

Trionyx  guttatus,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1869,  p.  66;  U.  S.  Geol.  Surv.  Wyoming,  etc., 
2d  (4th)  Ann.  Rept.  F.  V.  Hayden,  1871,  p.  367;  U.  S.  Geol.  Surv.  Montana,  etc.,  5th  Ann.  Rapt., 
F.  V.  Hayden,  1872,  p.  370;  Cont.  Ext.  Vert.  Fauna  West.  Terrs.,  1873,  pp.  176,  342,  plate  ix, 
fig.  I. — Cope,  Ext.  Bat.,  Rept.,  and  Aves  N.  A.,  1869,  pp.  151,  152;  U.  S.  Geol.  Surv.  Terrs., 
6th  Ann.  Rept.  F.  V.  Hayden,  1873,  p.  617;  Vert.  Tert.  Form.  West,  1884,  p.  119. — Hay,  Bibliog. 
and  Cat.   Foss.  Vert.  N.  A.,   1902,  p.  454. 

Aspideretes?  guttatus.  Hay,  Amer.  Geologist,  xxxv,  1905,  p.  335. 

Dr.  Joseph  Leidy's  type  of  this  species  was  discovered  at  Church  Buttes,  near  Fort  Bridget, 
Wyoming,  in  the  beds  of  the  Bridger  Eocene.  It  consists  of  a  portion  of  the  third  neural  plate, 
the  fourth,  fifth,  sixth,  and  seventh  neurals;  portions  of  the  third,  fourth,  fifth,  and  sixth 
costals  of  the  right  side;  the  proximal  ends  of  the  fifth,  sixth,  seventh,  and  eighth  costals 
of  the  left  side;  and  the  complete  seventh  and  eighth  costals  of  the  right  side.  The  materials 
are  therefore  not  very  satisfactory.  The  form  of  the  shell  can  not  be  determined,  nor  with 
certainty  the  presence  or  the  absence  of  a  preneural.  The  species  has  here  been  referred  with 
doubt  to  Aspideretes.  To  add  to  our  difficulties  the  type  appears  to  have  disappeared  from 
view.  Cope  referred  to  this  species  some  of  the  materials  collected  by  him  in  the  Bridger  beds, 
but  his  specimens  were  very  fragmentary  and  do  not  appear  to  have  furnisht  him  with  ad- 
ditional information.  It  is  questionable  whether  or  not  the  nearly  complete  carapace  collected 
by  him  in  the  Wasatch  beds  of  New  Mexico  really  belongs  to  the  species.  Unfortunately  this 
carapace  is  now  lost,  along  with  the  greater  part  of  Cope's  other  remains  from  that  region. 

Leidy  supposed  that  the  carapace  described  by  him  had  originally  had  a  length  of  about 
375  mm.  The  bones  had  a  thickness  of  about  8  mm.  Most  of  the  neurals  are  nearly  twice  as 
long  as  wide,  and  there  is  a  reduced  one  between  the  costals  of  the  seventh  pair.  The  costals 
and  neurals  are  described  as  being  sculptured  for  the  most  part  with  broad,  rounded,  and 
isolated  concave  pits  resembling  the  impression  of  rain  drops  on  a  soft  surface.  Near  the  bor- 
ders of  the  shell  these  become  somewhat  confluent.  The  walls  surrounding  the  pits  are  broad 
and  low  and  often  as  wide  as  the  pits.    There  are  2.5  or  3  of  these  pits  in  a  line  10  mm.  long. 

The  American  Museum  expedition  of  1903,  sent  into  the  Bridger  region  near  Fort  Bridger, 
secured,  in  the  Grizzly  Buttes,  a  specimen.  No.  6005,  which  is  referred  with  confidence  to 
this  species.  It  consists  of  a  portion  of  the  carapace  corresponding  nearly  with  that  of  the  type, 
together  with  a  large  portion  of  the  plastron.  The  fragment  of  the  carapace  agrees  in  all 
essential  respects  with  the  figure  and  description  furnisht  by  Leidy.  However,  the  sixth 
neural  plate  is  segmented  into  two  portions.  The  costals  appear  to  have  been  somewhat 
thicker,  ranging  from  7  mm.  to  10  mm.  The  distance  from  the  hinder  border  of  the  eighth 
costal  to  the  anterior  border  of  the  sixth  is  1 1 2  mm.  In  Leidy's  specimen  this  distance,  accord- 
ing to  his  figure,  was  133  mm.  Fig.  663a  is  composite,  being  constructed  partly  from  the 
specimen  just  described  and  partly  from  No.  5993  A.  M.  N.  H.,  described  below. 

The  plastron  (fig.  663^)  is  represented  by  nearly  the  whole  of  the  right  hyoplastron  and  a 
fragment  of  the  left;  the  whole  of  the  right  hypoplastron  and  a  fragment  of  the  left;  and  both 
nearly  complete  xiphiplastra.  At  its  median  end  the  border  of  the  hypoplastron  is  filled  out  to 
the  extremity  of  the  process  which  meets  that  of  the  opposite  bone  at  the  midline,  thus 
indicating  an  old  individual.  The  bones  are  thick  and  heavy.  On  the  bridge,  at  the  suture 
between  the  hyoplastron  and  the  hypoplastron,  the  thickness  is  17  mm.  The  bridge,  where 
narrowest,  is  79  mm.  wide.  Of  this  width  the  hyoplastron  occupies  49  mm.  Nearly  the 
whole  of  the  lower  surface  of  both  bones  is  roughened  or  granulated.  However,  the  outer  end 
of  the  hypoplastron  is  sculptured  with  ridges  and  tubercles,  of  which  there  are  about  six  in  a 
distance  of  10  mm.  A  similar,  but  more  indistinct  sculpturing  occupies  the  lower  surface  of 
the  outer  end  of  the  hyoplastron. 

The  xiphiplastra  are  triangular  in  form,  and  had  a  fontanel  between  their  inner  borders. 
Each  has  2  processes  for  articulation  with  the  corresponding  hypoplastron.  Two  processes  of 
the  left  xiphiplastron  received  between  them  a  single  process  of  the  right.  The  lower  surface 
of  the  two  bones  is  roughened,  but  not  sculptured. 

Fig.  664  represents  the  pelvis  of  this  specimen. 


504 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


A  specimen  of  a  large  trionychid  collected  in  1903,  in  the  western  part  of  Grizzly  Buttes, 
is  referred  to  this  species.  Its  catalog  number  in  the  American  Museum  of  Natural  History  is 
5917.  It  consists  of  the  outer  ends  of  the  nuchal,  the  greater  portion  of  the  right  first  costal, 
the  outer  ends  of  the  left  first  and  second  costals,  various  portions  of  other  costals,  I  neural,  and 
fragments  of  other  parts  of  the  skeleton.  The  individual  was  a  large  one.  The  first  costal 
near  its  proximal  end  was  about  75  mm.  wide  fore  and  aft;  the  second  costal  has  a  width 
equally  great.  The  sculpture  appears  to  be  identical  with  that  of  No.  6005,  consisting  of  large 
flat-bottomed  pits,  surrounded  by  walls  with  rounded  summits.  As  in  No.  6005,  there  is  a 
band  near  the  free  margins  of  the  carapace  which  has  no  pits,  but  which  presents  a  fine  net- 
work of  bony  fibers,  resembling  a  textile  fabric.  On  the  rear  of  the  carapace  of  No.  6005  this 
band  is  narrow.    In  the  case  of  No.  5917  the  band  is  considerably  broader,  25  mm.  or  more. 


Figs.  663  and  664. — Aspideretes  gutiatus. 


663a.  Carapace.    Xj- 

664^1.  Pelvis,  seen  from  left  side.    Xj- 


663!..  Plastron.    Xh 

6646.  Pelvis,  seen  from  below.    Xj. 


The  width  of  the  outer  end  of  the  nuchal  bone  exceeded  65  mm.  The  length  of  the  bone  from 
side  to  side  was  about  230  mm.  Apparently  only  a  relatively  narrow  strip  on  the  posterior 
border  of  the  nuchal  was  occupied  by  a  pitted  surface.  In  front  of  this  there  was  an  area 
about  25  mm.  wide  with  the  textile-like  appearance  noted  above.  The  ends  of  this  element 
present  ordinary  bony  tissue.  The  outer  extremities  of  the  nuchal  overlapt  the  free  ends  of 
the  ribs  of  the  first  costals. 

The  sutural  borders  of  the  costals  present  a  band  devoid  of  pits  and  is  finely  striated  at 
right  angles  to  the  sutures. 

Future  discoveries  must  decide  whether  or  not  this  identification  of  No.  5917  is  correct. 

Still  another  specimen.  No.  5993,  collected  in  1903,  in  the  eastern  part  of  the  Grizzly 
Buttes,  must  for  the  present  be  referred  to  A.  guttatus.    The  carapace  is  nearly  complete,  but. 


TRIONYCHID^. 


505 


like  No.  5917,  lacks  the  median  portion  of  the  nuchal  and  the  anterior  neurals.  Furthermore, 
the  sculptured  layer  has  been  split  off  the  nuchal.  The  length  of  the  carapace  was  close  to 
420  mm.;  the  width,  360  mm.  The  sixth  neural  was  not  completely  developt  and  it  permits 
the  costals  of  the  sixth  pair  to  join  behind  it.  The  seventh  neural  is  only  15  mm.  long  and  10 
mm.  wide,  and  it  is  wedged  in  between  the  sixth  and  seventh  pairs  of  costals. 

The  nuchal  had  a  width  of  60  mm.  from  front  to  back,  at  a  short  distance  from  the  midline. 
It  is  evident  from  the  right  fragment  of  the  nuchal  and  the  right  first  costal  that  there  was 
between  the  nuchal  and  the  first  costals,  one  on  each  side  of  the  first  neural,  a  pair  of  fontanels. 
Similarly  placed  fontanels  are  found  in  Platypeltis  leucopotamica.  In  A .  guttatus  these  fontanels 
were  about  25  mm.  fore  and  aft  and  at  least  20  mm.  from  side  to  side.  Between  the  fontanels 
of  No.  5993  is  a  small  triangular  plate  of  bone  which  may  represent  the  preneural.  On  account 
of  this  bone,  this  species  is  referred  to  the  genus  Aspideretes.  Without  this  it  would  fall  into 
the  genus  Amyda. 

This  specimen  is  nearly  devoid  of  the  smooth  marginal  band  of  interlaced  bony  fibers  so 
conspicuous  in  No.  5917. 

As  stated  above.  Professor  Cope  furnisht  a  brief  description  of  a  nearly  complete  carapace 
obtained  by  him  in  the  Wasatch  beds  of  New  Mexico  and  referred  by  him  to  this  species 
(Wheeler  Survey,  iv,  p.  46).  According  to  this  description  the  nuchal  underran  the  first 
costal.  This  is  not  the  case  with  the  specimen  described  above  and  it  is  concluded  therefore 
that  the  Wasatch  specimen  does  not  belong  to  the  same  species  as  Leidy's  type. 

Aspideretes  ellipticus  sp.  nov. 
Plate  95,  figs.  1-3;   text-figs.  665,  666. 

The  description  of  this  species  is  based  on  No.  1117  of  the  American  Museum  of  Natural 
History,  a  specimen  which  was  obtained  in  the  Bridger  beds  of  northeastern  Utah  by  the 
American  Museum  Expedition  of  1893. 

The  carapace  (plate  95,  fig.  i;  text-fig.  665)  is  complete;  the  plastron  is  wholly  missing. 
In  form  the  carapace  is  more  elongated  than  usual,  rounded  in  front,  only  slightly  truncated 
behind.  The  borders,  especially  the  anterior  and  lateral,  are  sinuous.  From  side  to  side  the 
carapace  is  gently  archt.  The  total  length  is  400  mm.;  the  width,  not  regarding  the  convexity, 
is  305  mm.  The  greatest  width  is  at  the  middle  of  the  length,  and  from  this  the  margin  pro- 
ceeds with  similar  curves  forward  and  backward.  The  thickness  of  the  costals  is  about  9  mm. 
at  the  sutures,  but  somewhat  greater  thru  the  ribs.  Along  the  sides  of  the  carapace  the  upper 
and  lower  layers  of  the  bones  project  beyond  the  median  layer,  thus  producing  a  groove.  The 
lower  layer  extends  far  out  on  the  distal  ends  of  the  ribs. 

Behind  the  nuchal  there  is  a  preneural,  followed  by  6  neurals.  The  table  herewith  presents 
the  measurements  of  these  bones. 

The  forms  of  these  bones  are  shown  in  the  figures. 

The  nuchal  has  an  antero-posterior  extent  of  50  mm.  and  a  lateral  extent  of  162  mm.  Its 
outer  extremities  overlap  the  projecting  ends  of  the  ribs  of  the  first  costals.    A  band  in  front 

and  at  the  extremities  is  not  occupied  by  the  sculptured 
layer  of  bone.  The  anterior  costal  bone  is  large,  having  a 
width  at  the  proximal  end  of  67  mm.  The  free  portions  of 
most  of  the  ribs  project  beyond  the  margin  of  the  carapace  at 
least  40  mm.  The  costal  plates  of  the  sixth,  seventh,  and 
eighth  pairs  meet  along  the  midline.  Those  of  the  eighth  pair 
are  well  developt. 

The  sculpture  of  the  carapace  (plate  95,  figs.  2,  3)  con- 
sists of  large,  rather  shallow  pits,  which  are  separated  by 
ridges  whose  summits  are  rounded.  Of  these  pits  there  are 
4  or  5  in  a  line  20  mm.  long.  They  are  largest  on  the  hinder 
half  of  the  shell.  There  is  only  a  slight  tendency  toward  confluence  into  rows  and  furrows. 
On  the  neural  bones  the  pits  are  not  so  distinct  as  on  the  costals. 

The  type  specimen  of  A .  ellipticus  was  buried  in  a  matrix  of  rather  coarse  sandstone. 

A  second  and  larger  specimen  of  this  species  was  collected  during  the  summer  of  1903  in 

the  Bridger  deposits  of  the  western  part  of  Grizzly  Buttes  of  Wyoming.    Its  catalog  number 


Element. 

Length. 

Greatest 

Width. 

Preneural 

Neural  i 

Neural  2 

Neural  3 

Neural  4.' . .. . 

Neural  5 

Neural  6 

38 
37 
48 
45 

44 
40 
21 

40 

28 

*5 
»4 
21 

17 
II 

5o6 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


in  the  American  Museum  of  Natural  History  is  5930.  The  convexity  and  the  outline  of  the 
carapace  are  very  similar  to  those  of  the  type.  The  front  margin  is  somewhat  more  excavated 
than  in  the  type,  and  the  lateral  borders  are  more  sinuated.  This  is  caused  by  the  extension 
of  the  sculptured  layer  out  on  the  distal  ends  of  the  ribs. 

The  length  of  the  specimen  is  450  mm.;  the  greatest  width,  380  mm.  The  preneural  is 
relatively  broader  anteriorly  than  in  the  type,  and  the  sixth  neural  is  not  developt.  In  the 
latter  respect  we  may  find  variations  in  our  living  species  of  Trionychidae. 

With  this  specimen  from  Wyoming  comes  a  considerable  portion  of  the  plastron.  This 
includes  the  median  half  of  the  left  and  a  fragment  of  the  right  hyoplastron,  and  a  considerable 
part  of  the  right  hypoplastron.  These  bones  are  thick  and  heavy,  the  thickness  of  the  bones 
along  the  suture  joining  them  on  the  narrowest  part  of  the  bridge  being  16  mm.  From  this 
point  the  thickness  is  reduced  each  way  to  about  10  mm.  at  the  median  and  outer  borders  of 
the  bones.  At  the  narrowest  part  of  the  bridge  the  width  of  the  hyoplastron  is  50  mm.;  of  the 
hypoplastron,  42  mm.  The  xiphiplastron  has  joined  the  hypoplastron  by  the  usual  two 
digitations.     The  lower  surfaces  of  the  hyoplastra  and  the  hypoplastra  are  occupied  by  a 


Figs.  665  and  666. — Aspideretes  ellipticus. 
665.  665.  Carapace  of  type.    XJ.  666.  Plastron.    Xj. 


nearly  obsolete  sculpture  of  pits  and  ridges.  This  is  most  distinct  on  the  outer  ends  of  the 
bones,  where  we  find  3  pits  in  a  line  of  10  mm.  This  sculpture  and  the  bone  supporting  it 
have  approacht  nearly  to  the  midline,  an  indication  that  the  individual  was  an  old  one. 
The  hyoplastra  and  hypoplastra  resembled  closely  those  of  Platypeltis  ferox,  of  Florida. 
Text-fig.  666  represents  what  is  known  of  the  plastron  of  this  species.  The  figure  is  con- 
structed partly  from  the  specimen  just  described,  partly  from  the  following  one. 

A  still  larger  example  of  this  species  was  collected  during  the  summer  of  1903  near  the 
mouth  of  Cottonwood  Creek,  Wyoming.  Its  catalog  number  in  the  American  Museum  of 
Natural  History  is  5979.  The  bones  of  the  median  line  and  of  the  left  side  are  complete, 
except  that  the  third  neural  is  wanting  and  portions  of  the  fifth,  sixth,  and  seventh  costals. 
Some  parts  of  the  right  side  are  present.    The  right  hyoplastron  is  quite  complete. 

The  length  of  this  specimen  is  510  mm.;  the  width  was  close  to  445  mm.  It  displays  a 
greater  convexity  of  the  carapace  than  is  seen  in  the  other  specimens.  The  nuchal  and  the 
preneural  resemble  closely  those  of  the  type.  The  sixth  neural  is  present,  but  small.  Altho 
the  individual  was  so  large  and  evidently  aged,  the  free  ends  of  the  ribs  project  beyond  the 
margin  of  the  carapace  a  distance  of  about  40  mm.    The  hyoplastron  is  identical  with  that  of 


TRIONYCHID^.  507 

No.  5930.  The  outer  anterior  process  was  evidently  flattened,  not  terete  as  usual  in  trionychids. 
The  pits  and  ridges  of  the  median  end  are  quite  distinctly  seen.  The  width  of  the  bone  where 
narrowest  is  53  mm. 

The  species  resembles  most  closely  A.  guttatus  (Leidy).  From  the  latter  it  differs  in  being 
more  elongated,  the  width  being  contained  in  the  length  seventy-six  hundredths  times,  in  J . 
guttatus,  eighty-five  hundredths  times.  The  sculpture  of  A .  ellipticus  is  coarser,  there  being 
4  or  5  pits  in  a  20  mm.  line,  while  in  A.  guttatus  there  are  5  or  6  pits  in  the  same  distance. 
The  bridge  of  the  plastron  of  ellipticus  is  wider  relatively  to  the  length  of  the  hyohypoplastral 
suture  than  was  A .  guttatus.  A .  guttatus  has  fontanels  in  the  front  of  the  carapace;  while 
A.  ellipticus  has  none. 

This  species  resembles  closely  the  form  described  in  this  work  as  A.  grangeri.  The 
distinctive  characters  are  discust  under  the  latter  species. 

Aspideretes  grangeri  sp.  nov. 
Plate  97,  fig.  1;   text-fig.  667. 

Among  the  fossils  collected  by  Mr.  Walter  Granger,  head  of  the  American  Museum 
expedition  to  the  Bridger  beds  in  1904,  was  the  fine  carapace  represented  on  plate  97, 
fig.  I.  Only  a  portion  of  the  middle  region  at  the  rear  is  missing.  The  specimen  bears 
the  catalog  number  3942.  It  was  collected  on  Cottonwood  Creek,  about  half  a  mile  below 
the  Henry's  Fork  stage  road.  The  level  is  given  as  B';  that  is,  the  upper  portion  of  the 
middle  Bridger. 

The  total  length  of  the  carapace  (plate  97,  fig.  i;  text-fig.  667)  was  383  mm.;  the  width 
of  the  disk,  317  mm.;  the  width  to  the  free  ends  of  the  ribs,  343  mm.  The  carapace  is  con- 
siderably archt  from  side  to  side,  the  midline  of  the  fossil  rising  to  a  height  of  105  mm.  above 
the  tips  of  the  free  rib  ends.  In  outline  the  carapace  is  broadly  oval,  or  elliptical,  slightly 
excavated  in  front,  and  probably  slightly  truncated  in  the  rear.  As  in  A.  ellipticus,  the  upper 
layer  of  the  carapace  overhangs  somewhat  the  middle  layer,  so  that  a  sort  of  gutter  runs 
around  the  edge  of  most  of  the  carapace.  The  free  border  of  the  fifth  costal  plate  is  7  mm. 
thick  near  the  suture,  and  n  mm.  thick  thru  the  rib.  The  nuchal  has  an  extent  from  side  to 
side  of  190  mm.;  a  fore-and-aft  extent  of  40  mm.  As  in  A .  ellipticus,  there  is  a  smooth  band 
along  the  front  and  the  ends  of  the  nuchal.  It  runs  at  a  lower  level  than  the  pitted  surface. 
It  is  about  7  mm.  wide  at  the  midline,  and  23  mm.  at  the  ends  of  the  bone. 

There  are  a  preneural  and  6  neurals.  Possibly  there  was  a  seventh  neural  of  small  size. 
The  table  below  gives  the  dimensions  of  these  bones. 

At  their  proximal  ends  the  costals  of  the  first  pair  have  a  width  of  59  mm.  At  the  distal 
end  they  are  only  39  mm.  The  next  four  have  the  proximal  ends  equal  in  width  to  the  lengths 
of  their  respective  neurals.  The  distal  end  of  the  costals  of  the  second  pair  is  expanded  to  a 
width  of  88  mm.    This  may  be  an  individual  variation.    The  costals  of  the  sixth  pair  probably 

joined  each  other  for  a  part  of  their  width  at  the  proximal 
ends.  Those  of  the  next  two  pairs  certainly  joined  their 
fellows  at  the  midline.  The  lateral  extent  of  each  costal  of 
the  eighth  pair  was  close  to  36  mm.  The  free  ends  of  the  ribs 
of  the  median  costals  projected  about  -^y  mm.  beyond  the 
border  of  the  disk. 

The  sculpture  of  this  species  consists,  as  is  usual  in  the 
family,  of  a  network  of  ridges  surrounding  shallow  pits. 
The  ridges  are  rounded  on  their  summits.  On  the  outer 
third  of  most  of  the  costals  the  pits  are  arranged  in  rows 
running  parallel  with  the  adjacent  border  of  the  carapace. 
On  the  nuchal,  the  neurals,  the  costals  of  the  first  pair,  and  the  proximal  two-thirds  of  the 
other  costals,  the  pits  are  irregularly  but  evenly  distributed.  On  the  greater  part  of  the  cara- 
pace there  are  5  or  6  of  the  pits  in  a  line  20  mm.  long.  On  the  anterior  third  of  the  carapace 
there  may  be  as  many  as  7  in  a  line  of  the  length  given.  Most  of  the  costals  have  a  narrow 
smooth  band  along  the  intercostal  sutures. 


Element. 

Length. 

Width. 

Preneural 

Neural  i 

Neural  2 

Neural  3 

Neural  4 

Neural  5 

Neural  6 

26 

39 
46 
44 
43 
38 
29 

n 
28 

3° 
27 
26 
20 

'S 

5o8 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


Fig.  667. — Asptderetes  grangeri. 
Carapace  of  type.     X  0. 


This  species  needs  to  be  compared  with  Asptderetes  ellipticus  and  A.  guttatus.  The  form  of 
the  carapace  is  about  the  same  in  the  three.    It  is  broader  than  in  the  type  oi  A .  ellipticus,  but 

slightly  narrower  than  in  another  specimen.  The  pre- 
neural  of  the  species  last  named  is,  in  all  the  known 
specimens,  considerably  longer  and  broader  than  in  the 
type  of  A.  grangen,  while  the  neurals  are  broader.  The 
proximal  ends  of  the  costals  of  the  first  pair  are  narrower 
in  A.  grangeri  than  in  A.  ellipticus,  their  width  being 
contained  in  the  length  of  the  carapace  6.33  times  in  the 
former  and  only  5.5  times  in  the  latter.  The  nuchal  is 
longer,  its  length  being  contained  in  the  length  of  the 
carapace  two  times;  in  A .  ellipticus  two  and  a  half  times. 
The  sculpture  of  the  carapace  is  coarser  in  A.  ellipticus 
than  in  A .  grangeri,  there  being  in  the  former  4  or  5 
pits  in  a  line  20  mm.  long  while  in  the  latter  there  are 
from  5  to  7.  In  making  comparisons  between  the  pits  of 
the  two  species,  measurements  must  be  taken  on  corre- 
sponding parts  of  the  shell;  36  measurements  taken  on 
all  parts  of  the  carapace  of  2  specimens  of  A .  ellipticus 
show  that  there  are,  on  an  average,  4.44  pits  in  a  20  mm. 
line;  18  measurements  made  on  corresponding  parts  of 
the  carapace  oi  A .  grangeri  indicate  an  average  of  5.83 
pits  in  the  distance  named;  that  is,  the  pits  of  the  former 
species  have  an  average  diameter  of  4.5  mm.  while  those 
of  the  latter  have  an  average  diameter  of  3.43  mm.,  a 
difference  of  a  little  more  than  i  mm.  In  A .  ellipticus 
the  small  pits  are  found  almost  wholly  on  the  nuchal  and  close  to  the  border  of  the  shell  toward 
the  front.  The  writer  regards  the  finer  sculpture  of  the  specimen  here  described  as  an  indi- 
cation of  a  distinct  species. 

The  sculpture  of  the  carapace  of  this  supposed  species  is  apparently  identical  with  that 
of  A.  guttatus  and  it  is  possible  that  the  specimen  ought  to  be  referred  to  the  latter  species. 
However,  the  type  oi  A.  grangeri  has  a  well-developt  preneural  bone  and  no  fontanel  on  each 
side  of  it;  whereas,  the  specimen  of  A .  guttatus  has  large  fontanels  and  only  a  rudimentary 
preneural.  A.  grangeri  is  a  strongly  archt  species.  It  is  possible  that  the  flatness  of  all  the 
specimens  oi  A .  guttatus  is  due  to  distortion  during  fossilization. 

Genus  AXESTEMYS  Hay. 

Axestus,  Cope,  Proc.  Amer.  Philos.  Soc,  xii,  1872,  p.  462.     (Preoccupied  in  entomology.) 
Axestemys,  Hay,  Amer.  Geologist,  xxiv,  1899,  p.  348. 

Plastron,  so  far  as  known,  without  the  usual  pits  and  ridges.  Nuchal  bone  partly  separated 
from  the  first  costals  by  fontanels.    Probably  no  preneural. 
Type:    Axestus  hyssinus  Cope. 

Professor  Cope  based  the  genus  Axestus  on  the  species  A.  hyssinus,  which  was  represented 
by  the  left  xiphiplastron,  most  of  the  pelvis,  the  larger  portions  of  both  femora,  both  humeri 
with  distal  ends  missing,  the  right  scapula  and  coracoid  complete,  a  cervical  vertebra,  two 
sacrals,  a  few  caudals,  and  some  phalanges.  This  type  belongs  to  the  U.  S.  National  Museum, 
but  the  caudal  vertebrae  and  the  phalanges  appear  to  have  been  lost. 

The  character  on  which  Cope  relied  for  separating  this  genus  from  other  genera  of  Trio- 
nychidae  is  found  in  the  absence  of  superficial  sculpture  on  the  lower  side  of  the  plastron,  and 
the  presence  there  of  a  layer  which  "is  marked  with  decussating  lines  of  osseous  deposits,  as  in 
woven  linen."  The  other  characters  given  by  him  in  his  generic  descriptions  are  probably 
common  to  most  of  the  Trionychidje. 

This  layer  of  decussating  bony  fibers  (plate  104,  fig.  4)  is  also  common  to  various  fossil 
and  living  species  of  Trionychidae,  and  may  be  seen  in  both  the  carapace  and  the  plastron  of 
Platypeltts  spinifera  near  the  borders  of  the  bones  where  the  sculptured  layer  thins  out. 
As  Cope  says,  such  a  layer  is  found  in  the  dermal  scutes  of  the  Crocodilia;    and  Marsh  has 


TRIONYCHID^.  5O9 

described  and  figured  the  dermal  scutes  of  a  dinosaur,  Nodosaurus  textilis,  which  are  markt 
by  similar,  but  coarser,  interwoven  bony  fibers. 

However,  since  there  appears  to  be  an  unusual  abundance  of  this  layer  of  fibers  and  a 
nearly  complete  absence  of  the  sculptured  layer,  the  so-called  callosities,  it  appears  advisable 
for  the  present,  to  retain  the  species  in  a  distinct  genus.  There  are  reasons  for  believing  that 
the  nuchal  bone  also  will  offer  some  characters  when  it  is  completely  known. 

Axestemys  byssina  (Cope). 
Plate  104,  fig.  4;    text-figs.  668,  669. 

Axcstus  hyssinus,  CoPE,  Proc.  Amer.  Philos.  Soc,  xil,  1872,  p.  462  {A.  bysimus,  misprint);  U.  S.  Geol. 

Surv.,  6th  Ann.  Rep.,  1872  (1873),  p.  616;  Vert.  Tert.  Form.  West,  1884,  p.  116,  plate  xv,  figs.  1-12. 
Axestemys  hyssinus.  Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  455;  Amer.  Geologist,  xxxv,  1905, 

P-  337- 

The  type  of  this  species,  now  in  the  U.  S.  National  Museum  at  Washington,  has  been 
studied  by  the  present  writer.  The  type  was  found  on  Black's  Fork  of  Green  River;  the  second 
specimen  on  upper  Green  River.  Both  probably  belong  to  level  B.  These  bones  were  figured 
by  Cope  in  his  great  work  The  Vertebrata  of  the  Tertiary  Formations  of  the  West,  the 
figures  having  half  the  size  of  nature.  These  bones  are  from  2.33  to  3  times  as  large  as  the  cor- 
responding ones  of  a  specimen  oi  Platypeltts  whose  carapace  is  147  mm.  long.  The  animal 
therefore  had  a  carapace  probably  over  420  mm.  in  length. 

The  xiphiplastron  (plate  104,  fig.  4;  text-fig.  668)  differs  from  that  oi  Platypeltis  spinifera 
in  having  the  posterior  process  narrower  and  more  elongated  and  in  having  the  callosity  wholly 
devoid  of  the  layer  which  ordinarily  furnishes  the  sculpture,  but  composed  of  a  layer  of 
textile-like  fibers  of  bony  tissue.  The  thickness  of  the  central  portions  of  this  bone  is  10  mm., 
that  of  the  living  species  just  referred  to  being  about  3  mm.  Hence  the  thickness  of  the 
plastron  of  the  fossil  species  under  consideration  is  proportionally  as  great.  The  greatest 
length  of  the  fragment  of  xiphiplastron  is  166  mm.  It  probably  had  a  length  originally  of 
188  mm.  The  shoulder-girdle  seems  not  to  have  differed  in  any  important  respect  from  that  of 
Platypeltis  spinifera.  The  humerus,  so  far  as  represented,  is  like  that  of  the  living  species 
referred  to,  except  that  the  head  appears  to  have  been  more  narrowly  oval,  with  the  plane 
thru  the  long  axis  parallel  with  the  long  axis  of  the  shaft  of  the  bone. 

The  femora  are  like  those  o(  Platypeltis  spinifera,  except  that  there  is  a  very  distinct  ridge 
on  the  middle  of  the  upper  surface  of  the  distal  half  of  the  shaft.  The  pelvis  appears  not  to 
have  offered  any  difference  worthy  of  mention.  The  cervical  vertebra  which  has  been  preserved 
is  certainly  the  seventh,  agreeing  in  every  way  with  that  of  Platypeltis  spinifera.  Its  centrum 
is  just  3  times  as  long  as  that  of  the  corresponding  cervical  of  the  specimen  of  Platypeltis 
referred  to  above. 

Professor  Cope  mentioned  another  bone,  a  hypoplastral,  which,  on  account  of  its  great 
thickness,  he  thought  might  belong  to  a  distinct  species.  This  bone  is  now  in  the  possession 
of  the  American  Museum  of  Natural  History  and  bears  the  number  1034.  Its  greatest  thick- 
ness, about  the  middle  of  the  bone,  is  14  mm.  and  this  is  not  so  much  greater  than  that  of  the 
xiphiplastron  that  it  can  not  belong  to  the  same  species.  The  lower  surface  is  like  that  of  the 
xiphiplastron  of  the  type.  The  form  of  this  bone  does  not  differ  from  that  of  the  same  bone  of 
Platypeltis. 

The  American  Museum  also  possesses  a  number  of  bones  which  include  the  greater 
portion  of  the  left  half  of  the  nuchal,  most  of  the  left  first  costal,  fragments  of  several  other 
costals,  and  a  fragment  of  plastral  bone.  They  bear  the  Museum's  number  1046.  The 
nuchal  bone  shows  conclusively  that  the  species  is  not  T.  scutumantiquum,  which  is  suggested 
by  the  character  of  the  sculpture;  while  the  remains  of  the  plastron  prove  that  they  belong  to 
Axestemys.  The  latter  are  thick,  and  hence  are  undoubtedly  of  the  same  species  as  the  thick 
hypoplastral  mentioned  by  Cope.  Until  additional  materials  are  forthcoming  we  may  refer 
them  to  A.  byssina.  The  piece  of  the  plastron  of  No.  1046  is  about  8  mm.  thick,  near  the  base 
of  one  of  the  processes  directed  toward  the  midline,  and  the  lower  surface  has  the  textile-like 
surface  of  the  type  specimen  of  the  species.  The  portion  of  the  nuchal  (fig.  669)  remaining  has  a 
fore-and-aft  extent  of  53  mm.  and  a  total  lateral  extent  of  102  mm.    The  mesial  end  approaches 


5 10  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

close  to  the  midline.  Seventy-five  millimeters  of  the  front  border  of  the  bone  is  present. 
The  greatest  thickness  of  the  bone  is  12  mm.,  but  most  of  it  is  thinner.  The  posterior  half  of 
the  upper  surface  is  ornamented  with  a  system  of  well-defined  and  rather  sharp  ridges  which 
inclose  pits.  Of  these  there  are  3  or  4  in  10  mm.  The  anterior  half  of  the  surface  was  devoid 
of  ornamentation,  but  is  markt  by  numerous  grooves  and  perforations  for  blood-vessels.  The 
connection  of  the  nuchal  with  the  first  neural  and  the  first  costal  was  apparently  like  that 
found  in  7 .  puercensis.  There  remains  on  the  posterior  border  of  the  nuchal  about  20  mm.  of 
the  dentated  sutural  edge  for  union  with  the  first  neural.  Distad  of  this  the  border  is  smooth 
for  a  distance  of  30  mm.;  so  that  there  have  evidently  existed  between  the  nuchal  and  the  first 
pair  of  costals  two  elongated  fontanels,  separated  by  the  anterior  neural.  At  the  distal  end  of 
each  fontanel  the  border  turned  backward,  to  come  into  contact  with  the  costal.  What  the 
breadth  antero-posteriorly  of  this  fontanel  was,  we  can  not  say,  but  since  there  appears  to  have 
been  only  a  single  neural  between  the  first  pair  of  costals,  the  fontanel  was  probably  narrow. 
The  greater  part  of  the  first  costal  is  present,  only  the  distal  extremity  being  gone.  The 
average  thickness  is  about  8  mm.  The  greatest  fore-and-aft  extent  is  57  mm.;  the  lateral 
extent  is  a  little  over  100  mm.,  the  thickness,  6  mm.  The  bone  was  originally  about  125  mm. 
long.  The  anterior  border  for  about  35  mm.  proximally  did  not  articulate  with  the  nuchal, 
but  formed  the  posterior  border  of  the  fontanel  already  mentioned.  Distad  of  this,  the  front 
edge  of  the  bone  was  deeply  grooved  for  the  hinder  edge  of  the  nuchal.    The  proximal  end  of 


DOS.                  V,,^/^:;               '.-  I                            """~^--^^.                       \     ; 

\             J           /"^  Figs.  668  and  669. — Axestemys  byssina.    X  J. 

\         /  ^^  /  ^'^'  Plastron.    Xiphiplastron  of  type;  hypoplastron  from 

\      /          /  No.  1034  A.  M.  N.  H. 

\         'i  /         /  669.  Part  of  nuchal  and  left  first  costal. 


the  bone  articulated  with  the  first  neural.  The  direction  of  the  proximal  border  shows  that 
the  anterior  neural  was  broader  at  the  anterior  end  than  behind.  The  hinder  border  of  the 
costal  is  jagged,  for  sutural  union  with  the  next  costal.  The  rib-end  of  the  first  costal  plate 
seems  to  have  been  overlapt  by  the  outer  end  of  the  nuchal. 

This  species  was  a  large  one.  The  free  borders  of  the  costals  were  beveled  off  very  ob- 
liquely to  a  sharp  edge  and  on  this  beveled  surface  decussating  bony  fibers,  like  those  of  the 
plastron,  are  seen  in  abundance.  How  far  the  free  portion  of  the  ribs  extended  beyond  the 
border  of  the  carapace  can  not  be  determined,  but  the  distance  must  have  been  considerable. 

The  sculpture  of  the  costals  resembled  that  of  the  nuchal;  but,  in  places  at  least,  the  pits 
are  larger  and  the  ridges  sharper.  The  walls  slope  away  gradually  toward  the  bottom  of  the 
pits.    There  is  little  or  no  tendency  toward  the  arrangement  of  the  pits  in  rows. 

There  appears  to  be  sufficient  reason  for  believing  that  the  plastral  and  the  carapacial 
bones  here  described  belonged  to  the  same  individual. 

Genus  AMYDA  Oken. 

Carapace  normally  with  8  pairs  of  costal  plates.  No  preneural  present.  One  or  more  of 
the  posterior  pairs  of  costals  may  be  in  contact  on  the  midline,  or  all  may  be  separated  by  the 
neurals.  Young  in  living  forms  with  numerous  longitudinal  dorsal  dermal  ridges  or  series  of 
tubercles. 

Type:    Trionyx  euphrattcus  Daudin. 


TRIONYCHID^.  fll 

The  living  species  included  by  the  present  writer  under  this  genus  are  those  embraced 
under  the  heads  I,  A  and  i,  B,  2  and  3,  of  Dr.  Boulenger's  synopsis  of  species,  on  page  244  of 
his  Catalogue  of  Chelonians.  The  type  of  the  genus  is  Trionyx  euphrattcus  of  the  same  work. 
It  is  possible  that  Trionyx  subplanus  Geoffr.  ought  to  be  regarded  as  the  type  of  the  genus 
Dogania.  Besides  the  fossil  North  American  species  whose  remains  are  complete  enough  to 
prove  that  they  belong  under  the  present  genus,  a  considerable  number  of  others  are  placed 
here  provisionally. 

For  a  discussion  of  the  name  Amyda  see  Stejneger,  Science,  xxi,  1905,  page  228. 

As  remarkt  under  the  genus  Aspideretes  it  seems  most  probable  that  the  upper  Cretaceous 
species  placed  here  under  Amyda  really  belong  under  Aspideretes. 

Key  to  North  American  Species  of  Amyda. 

A^.  Upper  Cretaceous  species: 

1.  Sculpture  coarse,  mostly  of  circular  pits,  about  4  in  line  of  16  mm prisca 

2.  Sculpture  still  coarser;   3  pits  in  line  15  mm.  long;   pits  deep,  rising  gradually  to 

summit  of  wall halophila 

A'.  Species  of  Atlantic  slope  Eocene: 

1.  Middle  of  costal  with  irregular  pits,  the  sutural  borders  with  ridges  somewhat 

oblique  to  the  borders;  about  2  ridges  in  a  10  mm.  line pennata 

2.  Costals   much  thicker   than    in  pennata;   pits  and  ridges   coarse  as  in  pennata 

but  irregular  or  in  rows  at  right  angles  with  the  sutural  borders virginiana 

A^.  Wasatch  species: 

1.  Costals  thick  and  growing  thicker  toward  outer  end;    sculpture  coarse;    irregu- 

larly arranged  and  deeply  imprest  pits;  4  or  5  in  line  20  mm.  long cartosa 

2.  Costals  thick;   sculpture  mostly  of  winding  and  anastomosing  ridges  inclosing 

pits  and  short  furrows;  2  or  3  ridges  crost  by  line  of  5  mm ventricosa 

3.  Costal  bones  thinner  than  in  cariosa;  the  sculpture  similar radula 

A*.  Bridger  species: 

1.  Carapace  nearly  as  wide  as  long;  front  of  nuchal  long  and  nearly  straight;   with 

a  smooth  band  in  front;   5  or  6  pits  in  20  mm aqua 

2.  Carapace  nearly  as  broad  as  long;   4  to  7  pits,  usually  5,  in  20  mm.  line;  no 

depression  along  back;  nuchal,  from  side  to  side,  0.64  the  width  of  the  shell ....      uinta'ensis 

3.  Carapace  nearly  as  wide  as  long;  a  conspicuous  depression  along  the  back;  length 

of  nuchal  0.80  of  width  of  shell;  with  a  smooth  band  in  front scutumantiquum 

4.  Costal  bones  thin;  on  proximal  ends  of  costals,  2  pits  in  10  mm.;  on  distal  ends, 

3  or  4;  some  ridges  crossing  the  costals  more  conspicuous  than  others concentrtca 

5.  Carapace  nearly  as  broad  as  long;    nuchal  not  half  as  wide  as  carapace;  sculp- 

ture of  median  coarseness,  3  pits  in  10  mm franctscis 

6.  Carapace   broader  than   long;    nuchal  nearly  0.6  the  width    of  the   carapace; 

sculpture  coarse  and  irregular,  on  central  portions  from  2  to  5  pits  in  20  mm.  .         sahbrosa 

7.  Carapace  about  as  broad  as  long;   the  bones  thin;   nuchal  concave  in  front,  its 

length  nearly  0.7  the  width  of  the  carapace;  a  smooth  band  along  its  front; 

sculpture  coarse,  about  2  pits  in  10  mm.  line exquistta 

8.  Carapace  nearly  as  broad  as  long;   rounded  in  front  and  behind;  nuchal  a  little 

more  than  half  the  width  of  the  carapace;  on  proximal  ends  of  costals,  3  pits 

in  15  mm.,  on  neurals  and  on  distal  ends  of  costals  5  or  6  pits  in  15  mm.  line.  .  mira 

9.  Known  only  from  skull,  which  resembles  that  of  A.  ferox;   crushing  surfaces  of 

upper  jaw  broad tritor 

10.  Carapace  nearly  as  broad  as  long;  nuchal  not  one-halfthe  width  of  the  carapace; 

sculpture  coarse,  3  or  4  pits  in  20  mm.  line egregia 

A^.  Uinta  species: 

I.  Carapace  broadly  oval;  nuchal  0.65  the  width  of  the  carapace;  sculpture  coarse, 

1  or  2  pits  in   10  mm.   line crassa 

A*.  Miocene  species: 

1.  Costals  thick  and  heavy;    crost   by  narrow,  sharp  ridges,  like  those  of  a  file, 

2  in  about   7  mm lima 

2.  Costals  not  so  thick;  ridges  closer  together  than  mlima  and  curving  across  costal  hutet 

3.  Pits  of  costals  closely  placed,  irregular  in  size  and  remarkably  deep cellulosa 


^12  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

Amyda?  prisca  Leidy. 
Plate  97,  figs.  2-6. 

Trionyx  priscus,  Leidy,  Proc.  Acad.  Nat.  Sci.  Phila.  1851,  p.  329;  Smith,son.  Cont.  Know!.,  xiv,  1869, 
art.  vi,  pp.  113,  120,  plate  xviii,  fig.  9. — Cope,  Cook's  Geol.  N.  J.,  1868,(1869),  p.  735;  Proc.  Acad. 
Nat.  Sci.  Phila.  1869,  p.  12;  Trans.  Amer.  Philos.  Soc,  xiv,  1869,  pp.  151,  153;  Vert.  Cret. 
Form.  West,  1875,  p.  260. — Maack,  Palasontogr.,  xviii,  1869,  p.  281. — Hay,  Bibliog.  and  Cat. 
Foss.  Vert.  N.  A.,  1902,  p.  454. 

The  original  description  of  this  species  given  by  Dr.  Leidy  was  exceedingly  brief,  present- 
ing merely  the  thickness  of  the  fragment  of  costal  plate  on  which  the  species  was  founded, 
and  the  statement  that  it  was  derived  from  the  Cretaceous  greensand  of  New  Jersey. 
Cope's  first  mention  of  it,  cited  above,  gives  only  the  name;  the  second  a  description  included 
in  two  lines;  the  third,  the  name  and  the  information  that  it  came  from  the  greensand  of  New 
Jersey;  the  fourth,  that  it  was  derived  from  the  greensand  No.  4,  by  which  he  meant  the 
equivalent  of  the  Pierre  beds  of  the  West. 

Maack  merely  refers  to  the  species  and  says  that  it  was  the  only  form  of  Trionyx  then 
known  from  the  Cretaceous. 

In  1869  Dr.  Leidy,  as  cited  above,  gave  a  detailed  description  and  a  figure  of  a  character- 
istic specimen.  This  specimen  must  be  regarded  as  the  type.  It  was  found  in  the  marl  on  the 
farm  of  G.  C.  Schenck,  in  Monmouth  County,  New  Jersey,  and  was  sent  to  Dr.  Leidy  by 
Professor  Cook,  then  state  geologist  of  that  state.  This  type  is  now  in  the  state  collection  at 
Rutgers  College,  New  Brunswick,  New  Jersey,  where  it  has  been  examined  by  the  writer. 
Leidy's  figure  of  the  specimen  is  reverst,  but  otherwise  correct.  The  pits  are  abruptly 
sunken  and  the  ridges  are  flat.  Pits  and  ridges  are  both  smaller  as  the  free  border  is  approacht. 
In  the  middle  of  the  length  of  the  fragment  there  are  4  ridges  in  a  line  16  mm.  long. 

Professor  Cope  states  (Trans.  Amer.  Philos.  Soc,  xiv,  p.  152)  that  the  costal  plate  men- 
tioned by  Leidy  as  coming  from  the  greensand  of  Burlington  County,  New  Jersey,  and  now 
in  the  collection  of  the  Academy  at  Philadelphia,  belongs  to  A.  halophila  (Cope). 

In  the  Cope  collection  of  reptiles  at  the  American  Museum  of  Natural  History  there  are 
about  a  dozen  fragments  of  the  carapace,  2  or  3  of  the  plastron,  the  distal  end  of  the  left 
humerus,  and  a  posterior  dorsal  vertebral  centrum.  These  specimens  are  credited  to  Dr.  C. 
Schenck,  Marlboro,  Monmouth  County,  New  Jersey,  probably  the  collector  of  Leidy's 
specimens.  The  number  of  the  lot  is  2401,  and  it  is  probable  that  it  represents  more  than  one 
individual.  These  fragments  were  identified  and  labeled  by  Cope  as  Trionyx  priscus.  Figures 
of  some  of  these  parts  are  here  presented.  Fig.  2,  plate  97,  represents  the  upper  end  of  a 
costal  plate,  the  portion  in  immediate  contact  with  the  neural  plate  being  broken  off.  The 
width  at  the  middle  of  the  piece  is  28  mm.;  the  thickness  at  the  sutural  border  is  7  mm.;  and 
that  thru  the  middle  of  the  width  is  8  mm.  Fig.  3  of  the  same  plate  shows  the  distal  end  of  a 
costal  bone,  but  no  sutural  edge  is  retained.  The  thickness  near  one  sutural  border  is  7  mm., 
while  thru  the  elevation  produced  by  the  rib  the  thickness  is  11  mm.  The  rib  projected 
beyond  the  border  of  the  costal  plate,  but  how  far  can  not  be  determined.  The  free  edge  of 
the  costal  plate  is  abruptly  rounded  off  in  section.  The  fragment  resembles  greatly  the  border 
portion  figured  by  Leidy,  and  this  author's  figure  shows  that  the  rib  projected  nearly  20  mm. 
beyond  the  costal  plate.  Leidy  regarded  the  costal  which  he  figured  as  belonging  to  the  left 
side,  but  it  seems  rather  to  belong  to  the  right.  Fig.  4  of  the  plate  referred  to  appears  to  be  a 
portion  of  the  nuchal;  but  if  so,  this  fragment  did  not  extend  to  the  midline  nor  show  the 
distal  end  of  the  bone.  It  indicates  that  there  was  a  median  excavation  in  the  front  of  the 
carapace,  and  a  fontanel  between  the  nuchal  and  the  first  costal  plate.  The  bone  is  only  5  mm. 
thick,  while  in  front  of  the  sculptured  surface  there  is  a  smooth  band.  Fig.  5  of  the  plate 
represents  what  appears  to  be  the  distal  end  of  the  hindermost  costal  plate  of  the  right  side. 
The  sutural  border  is  present  in  front.  The  projecting  rib  is  broken  off  just  after  leaving  the 
plate.  The  bone  is  8  mm.  thick  and  the  free  edge  is  cut  off  rather  abruptly  in  section.  Fig.  6 
is  a  portion  of  one  costal,  probably  from  the  middle  of  the  length.  The  shorter  of  the  two 
longer  borders  shows  the  suture. 

The  two  fragments  of  the  plastron  afford  but  little  light  regarding  its  structure.  It 
appears  to  have  been  1 1  mm.  thick  where  the  hyoplastron  and  hypoplastron  are  constricted 
between  the  legs  of  the  animal. 


trionychida:.  513 

The  sculpture  of  the  carapace  is  coarse,  and  consists  of  deep  pits  of  rather  regular  size, 
surrounded  by  walls  which  are  as  wide  as  the  pits  themselves.  The  figures  of  plate  97  show 
the  general  character  of  the  ornamentation.  The  ridges  which  run  across  the  costal  plates  are 
strongly  developt,  while  the  connecting  ridges  are  less  prominent.  There  are  four  rows  of  pits 
in  about  15  mm.  The  sides  of  the  pits  rise  more  abruptly  and  the  summits  of  the  ridges  are 
broader  and  more  rounded  than  in  A.  halophila.  On  the  proximal  ends  of  the  costal  plates, 
as  shown  by  fig.  2,  plate  97,  the  pits  are  arranged  irregularly  and  vary  much  in  size. 

The  pits  of  the  fragments  of  the  plastron  are  smaller  than  those  of  the  carapace  and  not 
so  deep. 

Until  more  of  the  carapace  of  this  species  shall  have  been  secured,  we  shall  be  uncertain 
as  to  its  generic  position. 

Amyda?  halophila  (Cope). 
Plate  96,  figs.  4,  5. 

Trionyx  hcdophtlus,  CoPE,  Proc.  Acad.  Nat.  Sci.  Phila.  1869,  p.  12;  Cook's  Report  Geol.  New  Jersey, 
1868  (1869),  Append.  B,  p.  735;  Trans.  Amer.  Philos.  Soc,  xiv,  1869,  p.  151,  plate  vii,  fig.  15; 
Vert.  Cret.  Form.  West,  1875,  p.  261. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  454. 

This  species  is  said  by  Professor  Cope  to  have  been  founded  on  numerous  portions  of  the 
carapace  and  plastron,  some  from  near  Summit  Bridge,  New  Castle  County,  Delaware,  and 
some  from  Camden  County,  New  Jersey.  Whether  or  not  these  represented  more  than  two 
individuals  we  are  not  informed.  In  the  Cope  collection  of  reptiles  in  the  American  Museum 
of  Natural  History  there  is  a  lot  of  bones.  No.  1476,  consisting  of  about  35  fragments  of 
costals,  neurals,  and  at  least  I  piece  of  the  plastron.  With  these  is  found  Cope's  label,  as 
follows:  "Trionyx  halophilus  Cope.  Type  spec.  Pits  of  Benj.  Biggs,  Summit  Bridge,  New 
Castle  County,  Del.,  1867."  In  George  H.  Cook's  Geology  of  New  Jersey,  p.  734,  Cope 
states  that  in  New  Jersey  this  species  comes  from  the  lower  marl  bed  of  the  Cretaceous. 

It  is  difficult  to  determine  what  meaning  to  attach  to  Cope's  use  of  the  terms  "No.  i," 
"No.  2,"  etc.,  in  his  table  of  measurements  on  page  152,  of  the  Transactions  American  Philo- 
sophical Society,  as  cited  above.  It  may  mean  that  he  had  portions  of  5  individuals,  which  is 
the  more  probable  conclusion.  He  speaks  of  having  one  costal  plate  which  retained  a  portion 
of  the  head  of  one  rib,  and  in  the  measurements  he  mentions  it  as  "costal  plate  No.  I."  This 
fragment  is  yet  in  the  collection,  and  is  the  one  figured  by  him;  but  it  is  not  the  first  costal. 
His  "centrum  vertebra  No.  2"  is  also  present,  but  the  shortness  of  the  neural  plate  attacht  to 
it,  only  27  mm.,  appears  to  indicate  that  it  is  one  of  the  posterior  neurals. 

This  species  was  a  rather  large  one,  the  length  of  the  carapace  of  the  individual,  or  indi- 
viduals, represented  by  the  remains  before  us,  having  probably  been  about  275  mm.  The 
larger  fragments  of  costal  plates  indicate  that  the  carapace  was  considerably  archt  from  side 
to  side.  The  shell  was  quite  thick  and  heavy;  and  the  ribs  stood  out  prominently  on  the  under 
side  of  the  distal  ends  of  the  costal  plates.  The  thickness  at  the  sutural  border,  at  the  outer 
end  of  one  costal  is  8  mm.,  while  thru  the  rib  it  is  15  mm.  The  width  of  the  costal  at  the 
outer  end  was  at  least  56  mm.  On  plate  96,  fig.  4,  is  represented  of  the  natural  size  a  neural 
plate  and  a  portion  of  a  costal  which  belonged  together.  They  are  the  same  bones  that  Cope 
has  figured.  The  greatest  length  of  the  neural  is  37  mm.;  the  greatest  width,  35  mm.;  the 
thickness,  8  mm.  The  length  of  the  fragment  of  costal  is  60  mm.;  its  width,  38  mm.;  its  thick- 
ness, at  the  costal  margin,  7  mm.;  at  the  middle  of  the  width,  9  mm.  The  inner  surface  dis- 
plays the  base  of  the  rib-head.  Cope  states  that  his  figure  is  half  the  natural  size  but,  while 
the  length  of  the  figure  of  the  piece  of  costal  is  slightly  more  than  half  the  size  of  the  original, 
the  dimensions  of  the  other  portions  are  three-fifths  of  their  natural  size.  Fig.  5  of  plate  96 
represents  a  portion  from  the  middle  of  the  length  of  a  costal  plate.  The  right  and  left  sides 
of  the  figure  are  the  sutural  borders. 

The  neural  plate  which  surmounts  the  centrum  spoken  of  by  Cope  as  "No.  2"  is  damaged 
somewhat,  but  it  has  had  a  length,  in  the  midline,  of  25  mm.  and  a  width  of  28  mm.  The  pos- 
terior border  is  convex,  the  anterior  concave. 

The  slight  evidence  afforded  by  one  costal  indicates  that  the  free  border  was  rounded 
off  in  section.    The  rib  projected  somewhat  beyond  the  edge  of  the  plate. 

33 


SH 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


The  sculpture  of  this  species  is  peculiar.  It  consists  of  rather  large  pits  of  quite  regular 
size  and  form.  They  are  rather  deep,  and  from  the  bottom  of  each  the  surface  rises  gradually 
to  the  top  of  the  wall  surrounding  them,  thus  being  bowl-shaped.  In  A .  prisca  (Leidy)  and 
some  other  species,  the  wall  around  the  pit  is  more  abrupt.  Usually  three  pits  occupy  a  line  of 
15  mm.  On  the  small  portion  of  the  plastron  referred  to,  the  pits  are  only  about  half  as  large 
as  those  of  the  carapace,  and  are  much  shallower. 

Among  the  fragments  supposed  to  belong  to  this  species  is  one  which  seems  to  have  formed 
a  portion  of  the  nuchal.  If  this  identification  is  correct,  this  bone  was  rather  thin  where  it 
joined  the  first  neural  and  first  costals,  but  very  thick,  1 1  mm.,  near  the  anterior  border.  The 
free  border  was  rounded  in  transverse  section.  At  the  midline  this  bone  was  only  about  22  mm. 
wide  fore  and  aft,  but  it  widened  rapidly,  being  38  mm.  wide  at  a  distance  of  about  40  mm. 
from  the  midline.  Thus  the  carapace  appears  to  have  been  deeply  and  broadly  excavated  in 
front.  There  is  present  a  piece  of  some  portion  of  the  plastron.  It  is  probably  the  bone  which 
Cope  regarded  as  a  part  of  the  xiphiplastron.    It  has  a  thickness  of  13  mm. 

There  is  in  the  Philadelphia  Academy's  collection  a  fragment  of  a  costal  plate  which  is  to 
be  referred  to  this  species.  It  was  found  at  Camden,  New  Jersey.  This  fragment  is  38  mm. 
wide  and  represents  about  half  the  width  of  the  costal.  The  thickness  at  the  sutural  border 
is  10  mm.;  thru  the  ridge  formed  by  the  rib,  12  mm.    There  are  4  pits  in  a  line  20  mm.  long. 

Cope  thought  that  this  and  some  of  the  other  species  of  Trionychidae  were  inhabitants 
of  the  sea,  and  he  refers  to  a  statement  of  Du  Chaillu  to  the  effect  that  Amyda  triunguis  had 
been  found  at  sea.  The  fact  may  be  mentioned  that  there  is  in  the  American  Museum  of 
Natural  History  a  specimen  of  Amyda  sinensis  (Wiegm.)  which  was  captured  in  1902,  by  Mr. 
N.  G.  Buxton  in  Vladovostock  Harbor,  Siberia. 

Amyda?  pennata  (Cope). 
Plate  96,  fig.  6. 

Trionyx  pennatus,  CoPK,  Proc.  Acad.  Nat.  Sci.  Phila.  1869,  p.  12;  Cook's  Report  on  Geol.  New  Jersey, 
Append.  B,  1868  (1869),  p.  734;  Trans.  Amer.  Philos.  Soc,  xiv,  1869,  pp.  151,  152,  plate  vii,  fig. 
13. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  454. 

As  in  the  case  of  too  many  of  our  fossil  tortoises,  our  knowledge  of  this  species  is  meager. 
The  species  was  based  on  a  portion  of  the  distal  end  of  a  costal  bone,  which  was  found  in  the 
upper,  or  Eocene,  bed  of  greensand,  probably  near  Squankum,  Monmouth  County,  New 
Jersey,  by  Mr.  O.  B.  Kinne.  The  specimen  is  now  a  part  of  the  Cope  collection  of  reptiles 
in  the  American  Museum  of  Natural  History,  and  bears  the  number  1165.  Cope,  as  cited, 
figured  the  type  half  the  natural  size.  On  plate  96,  fig.  6,  of  the  present  work,  it  is  repre- 
sented of  the  natural  size. 

The  fragment  is  supposed  to  include  a  little  more  than  two-thirds  the  width  of  the  distal 
end  of  the  costal,  unless  the  rib  lay  nearer  one  sutural  border  than  to  the  other.  The  costal 
had,  therefore,  probably  a  width  of  about  60  mm.  On  the  left  of  the  bone,  47  mm.  of  the 
sutural  border  is  shown.  At  the  proximal  end  of  this  border,  the  thickness  is  7  mm.  At  the 
distal  end  it  is  10  mm.  Where  the  rib  left  the  costal  plate,  the  thickness  is  13  mm.  The  free 
border  of  the  costal  is  cut  off  at  a  right  angle  with  the  upper  surface. 

The  sculpture  is  of  a  coarse  pattern.  The  ridges  are  broad  and  rounded,  but  the  diameter 
is  usually  less  than  that  of  the  intervening  furrows.  In  the  type,  the  ridges  run  from  the  sutural 
border  of  the  bone  inward  and  somewhat  toward  the  distal  end,  and  this  arrangement  evidently 
suggested  the  name  pennatus.  Soon  there  appear  connecting  ridges  and  the  furrows  become 
broken  up  into  large  and  small  pits.  Near  the  border  there  are  2  furrows  in  10  mm.  Many  of 
the  pits  in  the  median  portion  of  the  costal  are  of  less  diameter  than  the  surrounding  walls. 

Besides  the  type,  there  is  now  in  the  American  Museum  a  fragment  of  a  costal.  No.  2221, 
which  belongs  to  this  species.  The  bone  shows  67  mm.  of  one  sutural  border  and  8  mm.  of  the 
one  opposite.  The  width  of  the  bone  was  44  mm.  The  thickness  of  the  sutural  border  at  one 
end  is  7  mm.;  at  the  other,  9  mm.;  thru  the  rib,  12  mm.  In  this  fragment  the  principal 
ridges  of  the  ornamentation  run  at  nearly  right  angles  with  the  sutural  borders,  while  the  pits 
are  very  irregular  in  form  and  size. 

At  what  locality  this  specimen  was  collected  there  is  no  information;  but  it  is  very  cer- 
tain that  it  was  obtained  in  the  greensand  of  New  Jersey. 


TRIONYCHID^.  5I5 

Amyda?  virginiana  (Clark). 

Plate  96,  figs.  7,  8;    text-figs.  670,  671. 

T^rionyx  i;/r^/n/an;ij,  Clark,  Johns  Hopkins  Univ.  Bull.,  xv,  1895,  p.  4;  Bull.  No.  141,  U.  S.  Geol. 
Surv.,  1896,  p.  59,  plate  viii,  figs.  la,  lb. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  455; — 
Case,  Maryland  Geol.  Surv.,  Eocene,  1901,  p.  97,  plate  xi,  figs,  i,  2. 

All  the  known  specimens  of  the  present  species  were  found  at  Aquia  Creek,  Virginia,  in 
Eocene  deposits  belonging  to  the  Aquia  Creek  stage.  The  type  fragments  consist  of  a  portion 
of  the  distal  end  of  a  costal  plate  and  of  what  appears  to  be  the  proximal  end  of  another  costal, 
but  which  is  possibly  the  outer  end  of  the  left  hypoplastron. 

— ■ — — — — ____^  The   first-mentioned   fragment  represents 

)  about  half  of  the  width  of  the  costal.   Figure 

X^  670  shows  a  section  along   the   broken   edge, 

~"         \^,^  the  distal  end  being  toward  the  right.    At  the 

g_Q  ~~-^^,^^\.  proximal  end  the  fragment  is   17  mm.  thick. 

^~~^       Toward  the  distal  end  this  increases  to  26  mm., 

then   drops    off   suddenly   to  half  the    latter 

(      ^"^ --_^^ thickness,  then  runs  out  to  a  thin  edge.    At  the 

1  j"7'-  sutural  border  the  thickness  is  slightly  greater 

"' --S^^^^  ^1  than  at  opposite  points  on  the  broken  border. 

...  This  shows  that  there  is  no  ridge  produced  by 

Vigs.670A^d6-ji -Jmyda?v,rg.n,ar,a.   Sections     ^^^  ^.^      ^,^^  sculpture  (plate  96,  fig.  7)  con- 
of  costal  bones  of  type.     X  J.  •  .      r   •  j  j  r        j         ■   l  1 

^  ^  sistsoi  ridges  and  grooves  placed  at  right  angles 

670.  Section  parallel  with  intercostal  suture.  with  the  sutural  border.    There  are  a  few  ridges 

571.  Section  at  right  angle  with  intercostal  suture.  ■  ,  u         t  ■         »L 

'  *        ^  crossing  the  grooves,  breaking  them  up  into 

circular  and  elongated  pits.  Five  pits  and  as  many  ridges  are  found  in  a  line  22  mm.  long. 
Toward  the  line  where  the  thickness  is  suddenly  reduced  the  sculpture  becomes  obscure. 
There  is  no  smooth  band  along  the  sutural  border. 

The  pits  of  this  costal  have  the  same  size  as  in  J.  pennata  (Cope),  of  the  Eocene  of  New 
Jersey.  However,  in  the  latter  the  pits  are  arranged  in  rows  that  run  from  the  sutural  edges 
toward  the  middle  of  the  bone  and  at  the  same  time  toward  the  distal  end.  In  A.  pennata  the 
rib  produces  a  decided  thickening  on  the  under  side  of  the  distal  end  of  the  costal. 

The  second  piece  (plate  96,  fig.  8)  of  the  type  of  A.  virginiana  (Clark,  fig.  ih)  has  a 
thickness  of  13  mm.  at  the  distal  end  of  the  bone,  increasing  toward  the  other  end  to  15  mm. 
Fig.  671  is  a  section  across  this  bone.  From  the  sutural  border  the  bone  increases  to  22  mm. 
thickness,  an  increase  due  to  the  presence  of  the  rib  on  the  under  side  of  the  bone.  This  costal 
plate  appears  to  have  been  about  80  mm.  wide.  An  objection  to  regarding  this  fragment  as 
the  outer  end  of  the  left  hypoplastron  is  the  fact  that  the  ridge  runs  parallel  with  the  sutural 
border,  instead  of  approaching  it  in  one  direction. 

The  sculpture  of  this  fragment  differs  from  that  of  the  other  in  having  the  ridges  con- 
siderably broken  up  and  quite  irregular  in  direction.  The  pits  are  slightly  larger,  there  being 
5  of  them  in  a  line  25  mm.  long.  Along  the  sutural  border  there  is  a  band  15  mm.  wide  which 
is  markt  only  by  striations  at  right  angles  with  the  sutural  edge.  It  is  possible  that  in  these  two 
fragments  we  have  two  distinct  species. 

Amyda?  cariosa  (Cope). 
Plate  86,  figs.  9,  10. 

Trionyx  cariosus,  Cope,  Syst.  Catalogue  Vert.  Eocene,  New  Mexico,  1875,  p.  35;  Ann.  Rept.  Chief  of 
Engineers,  1875,  p.  1025  {of  separata,  p.  95);  Wheeler's  Surv.  W.  looth  Merid.,  1877,  p.  44,  plate 
xxvi,  figs.  5-10;   Vert.  Tert.  Form.  West,  1884,  p.  118. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A., 

1902.  P-  453- 

The  type  specimens  of  this  species  are  in  the  U.  S.  National  Museum  at  Washington,  and 
have  the  catalog  number  2575.  Those  which  Cope  figured  consist  of  fragments  of  costal 
bones,  I  neural,  and  a  supposed  xiphiplastral.  Cope  mentions  also  a  hypoplastral  as  being 
among  his  materials.  The  species  is  characterized  by  the  coarse  sculpture,  the  thickness  of 
the  bones,  and  the  longitudinal  grooving  of  the  margins  of  the  carapace.  The  type  was  found 
in  the  Wasatch  beds  of  New  Mexico,  by  Professor  Cope,  in  1874,  along  the  Gallinas  River. 


5l6  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

As  regards  the  thickness,  Cope  states  that  one  costal  was  7  mm.  thick  at  the  proximal  end, 
and  that  others  were  11  mm.  and  12  mm.  thick  at  the  middle  of  the  length  and  at  the  distal 
ends.  At  the  free  margins  of  the  costals  the  upper  layer  of  bone  projected  far  beyond  the  lower 
layers,  causing,  as  Cope  states,  a  deep  longitudinal  grooving  of  the  free  border  of  the  carapace. 
The  costals  had  a  width  of  about  45  mm.  at  the  proximal  end  and  of  about  60  mm.  at  the 
distal  end.  In  Cope's  figures  the  width  of  the  ridges  is  exaggerated  and  the  pits  are  made  to 
appear  too  abruptly  sunken. 

The  figures  publisht  by  Cope  show  that  there  are  on  the  proximal  ends  of  the  costals 
deeply  imprest  and  irregularly  arranged  pits,  of  which  there  are  four  or  five  in  a  line  20  mm. 
long.  Along  the  sutural  borders  of  each  of  the  costals  there  is  a  smooth  strip.  More  distally 
the  pits  arrange  themselves  in  irregular  rows,  and  sometimes  coalesce  to  form  furrows,  which 
run  parallel  with  the  margin  of  the  carapace.  Of  these  there  are  about  three  in  20  mm.  In 
Cope's  figure  7  the  ridges  and  furrows  are  not  represented  with  enough  distinctness.  On  the 
neurals  there  was  a  honeycomb  of  pits  similar  to  those  on  the  adjacent  ends  of  the  costals. 
Cope  says  that  the  hypoplastron  in  his  possession  presented  a  rather  irregular  reticulate 
sculpture  medially.  The  element  figured  as  a  probable  xiphiplastron  had  a  patch  of  large 
pits;  but  this  bone  is  really  the  left  extremity  of  the  nuchal.  The  figure  is  inverted.  The  right 
extremity  of  the  nuchal  is  present  likewise. 

Fig.  9,  plate  86,  reproduced  from  Cope,  gives  a  view,  natural  size,  of  a  portion  of  a  neural 
bone,  while  fig.  10  of  same  plate  shows  a  fragment  of  a  costal  plate. 

A.  radiila  has  a  style  of  ornamentation  quite  similar  to  that  of  the  present  species;  but 
the  shell  is  thinner,  and  the  free  margins  are  beveled  off,  instead  of  having  the  upper  layer  of 
bone  overhanging  the  lower  layers. 

Amyda?  ventricosa  (Cope). 
Plate  98,  figs.  1-6. 

Trionyx  ventricosus.  Cope,  Extinct  Vert.  New  Mexico,  in  Wheeler's  Surv.  W.  looth  Merid.,  iv,  1877, 
p.  45;  plate  Ixiv,  figs.  7-13;  Vert.  Tert.  Form.  West,  1884,  pp.  118,  188. — Hay,  Bibliog.  and 
Cat.  Foss.  Vert.  N.  A.,   1902,  p.  455. 

This  species  is  represented  by  somewhat  more  than  25  fragments,  which  Cope  states  belong 
to  3  individuals.  Of  these  fragments,  7  are  figured  in  Cope's  work  in  the  Wheeler  Survey,  as 
cited  above.  All  these  specimens  belong  to  the  U.  S.  National  Museum  and  bear  the  number 
1 1 12.  Of  the  pieces  figured  by  Cope,  all  are  present,  except  the  one  which  furnisht  fig.  10  of 
the  plate  cited.     New  figures  of  these  are  here  furnisht,  except  of  the  missing  fragment. 

This  species  was  found  by  Cope  in  the  year  1874,  in  the  Wasatch  deposits  of  Rio  Arriba 
County,  New  Mexico. 

Fig.  I  of  plate  98  (Cope's  fig.  13)  represents  the  distal  end  of  the  left  hypoplastron.  This 
bone  indicates  that  the  width  of  the  hypoplastron  at  the  narrowest  portion  was  20  mm.,  and 
that  the  various  dimensions  of  at  least  the  distal  end  of  the  bone  were  about  as  they  are  in 
Platypeltis  spinifera.  Cope  states  that  the  "twin  gomphosial  processes"  were  short  and  stout 
but  these  are  not  figured,  and  probably  were  not  present  on  any  of  the  specimens  when  found. 
The  processes  referred  to  separated  from  each  other  before  they  left  the  edge  of  the  "cal- 
losities," and  hence  were  probably  short.  The  thickness  of  the  bone  where  these  processes 
part  is  10  mm.;  at  the  sutural  edge  for  union  with  the  hyoplastron  the  thickness  is  7  mm.  The 
ornamentation  consists  of  narrow  ridges  which,  near  the  free  border  of  the  bone,  curve  around 
mostly  parallel  with  these  free  borders;  elsewhere,  they  are  irregular  in  their  course.  These 
ridges  are  frequently  connected  by  cross-ridges,  and  the  intervening  spaces  form  pits  and  short 
furrows  wider  than  the  ridges.     Usually  there  are  2  or  3  pits  in  a  space  of  about  5  mm. 

Fig.  2  of  plate  98  (fig.  12  of  Cope)  presents  the  same  part  as  the  previous  figure,  but  of 
another  individual;  but  it  ofl^ers  no  peculiar  features.  The  same  bone  of  a  third  individual 
was  larger,  the  thickness  at  the  base  of  the  twin  processes  being  14  mm.  Fig.  3  of  the  same 
plate  (fig.  1 1  of  Cope)  is  a  fragment  undetermined  as  to  position,  but  probably  belonging  to 
the  plastron.  It  is  about  7  mm.  thick.  The  ridges  and  pits  of  the  sculpture  have  no  regular 
arrangement,  and  the  sculpture  turns  over  the  edge  just  below  the  outstanding  process  on  one 
side.     Fig.  4,  plate  98  (fig.  7  of  Cope),  shows  the  distal  end  of  a  costal  plate,  including  the 


TRIONYCHIDiE.  51 7 

sutural  edge  on  one  side.  At  the  junction  of  the  sutural  border  with  the  free  border,  the  thick- 
ness is  ID  mm.  On  the  sutural  border,  at  the  end  of  the  fragment  toward  the  midline,  the 
thickness  is  reduced  to  8  mm.;  that  is,  this  costal  is  thicker  at  the  outer  end  than  nearer  the 
midline.  This  and  other  fragments  show  that  the  free  edge,  on  each  side  ot  the  rib  extension, 
was  cut  off  at  nearly  right  angles  with  the  sculptured  surface.  The  sculpture  came  down  close 
to  the  distal  ends  of  the  costal  plates.  In  some  cases,  but  not  all,  there  is  a  tendency  for  the 
pits  to  arrange  themselves,  at  the  ends  of  the  costals,  somewhat  parallel  with  the  free  border 
of  the  bone. 

Fig.  5  (fig.  9  of  Cope)  is  a  portion  of  the  costal  plate  of  a  small  individual.  The  width  is 
21  mm.;  the  thickness,  only  4  mm.  Fig.  6  (fig.  8  of  Cope)  represents  a  fragment  from  prob- 
ably the  proximal  end  of  a  costal  plate.  Here  the  ornamentation  consists  of  tubercles  and 
short,  winding,  and  occasionally  anastomosing,  ridges,  the  pattern  being  somewhat  coarser 
than  that  of  the  plastron,  there  being  two  furrows  or  pits  in  about  5  mm.  This  is  true  of  most 
of  the  ornamentation  of  the  carapace. 

Amyda  radula  (Cope). 
Plate  86,  figs.  11,  12. 

Trionyx  radulus,  CoPE,  Systematic  Cat.  Vert.  Eocene  New  Mexico,  1875,  p.  35;  Report  on  Geol. 
N.  W.  N.  Mex.,  in  Appendix  Ann.  Rep.  Chief  of  Engineers,  1875,  p.  1015  (of  separata,  p.  95); 
Wheeler's  Surv.  W.  looth  Merid.,  iv,  1877,  p.  45,  plate  xxvi,  figs.  11-16. — Hay,  Bibliog.  and  Cat. 
Foss.  Vert.  N.  A.,  1902,  p.  454. 

In  his  original  description  Professor  Cope  characterized  with  great  brevity  this  species  of 
Amyda.  In  his  final  report  on  his  explorations  in  New  Mexico,  publisht  in  the  fourth  volume 
of  the  Wheeler  Survey,  he  gave  some  additional  data  and  figures  of  some  of  the  fragments  on 
which  he  had  based  the  species.  Even  here,  however,  the  description  is  limited  to  10  lines  of 
print.  The  type  specimens  are  now  in  the  U.  S.  National  Museum,  at  Washington,  No.  2581. 
They  were  collected  in  Wasatch  deposits  along  the  Gallinas  River,  New  Mexico. 

The  figures  given  by  Professor  Cope  make  the  summits  of  the  ridges  surrounding  the  pits 
appear  too  broad.  They  are  really  narrow.  From  their  summits  the  walls  slope  rapidly  to  the 
bottoms  of  the  pits,  but  not  so  abruptly  as  the  figures  indicate. 

Cope's  fig.  II  represents  the  distal  end  of  a  costal.  It  has  a  thickness  of  6  mm.  In  the 
original  of  fig.  13  the  free  border,  at  the  side  of  the  extension  of  the  rib,  is  cut  off  nearly  square, 
with  a  tendency  of  the  upper  layer  to  overhang.  It  will  be  observed  that  the  sculpture  of  this 
and  of  the  costal  of  his  fig.  14  (plate  86,  fig.  11)  comes  down  close  to  the  free  border  of  the  bones. 
Cope's  fig.  15  (plate  86,  fig.  12)  represents  the  middle  of  a  costal.  The  sutural  border  is  4  mm. 
thick.  There  are  6  pits  in  a  line  20  mm.  long.  His  fig.  16  is  that  of  a  neural  which  has  a  thick- 
ness of  6  mm.;  and  there  are  5  pits  in  a  line  15  mm.  long.  In  these  specimens  the  rib  does 
not  stand  out  prominently  on  the  under  side  of  the  costal. 

Cope  (Vert.  Tert.  Form.  West,  p.  119)  identified  with  this  species  some  portions  of  a 
carapace  found  in  the  Bridger  beds.  This  is  here  described  under  Amyda  aqua.  For  a 
discussion  of  the  relationships  of  the  Wasatch  species  and  the  closely  related  A.  aqua  of  the 
Bridger  see  under  the  latter.  It  is  greatly  to  be  desired  that  additional  materials  of//,  radula 
from  the  type  locality  shall  soon  be  discovered  and  described. 

A.  radula  has  the  sculpture  similar  to  that  of  A.  cariosa.  The  two  appear  to  be  distin- 
guish! by  the  greater  thickness  of  the  shell  of  the  latter  and  the  groove  around  its  free  margin. 

Amyda  aequa  sp.  nov. 

Plate  99,  figs.  1-3;   text-figs.  672,  675. 

Trionyx  radulus,  CoPE,  Vert.  Tert.  Form.  West,  1884,  p.  119. 
Amyda  radulus.  Hay,  Amer.  Geologist,  xxxv,   1905,  p.  336. 

In  the  work  above  cited  Professor  Cope  described  and  referred  to  his  Trionyx  radulus,  of 
the  Wasatch  of  New  Mexico,  some  remains  of  a  trionychid  which  he  found  in  the  Bridger  beds 
of  Wyoming.  This  Bridger  individual  now  belongs  to  the  American  Museum  of  Natural 
History  and  has  the  number  1052. 


5l8  FOSSIL    TURTLES    OF    NORTH    AMF,RICA. 

The  nuchal  is  now  280  mm.  long  from  side  to  side,  and  it  was  originally  perhaps  nearly 
300  mm.  The  fore-and-aft  measurement  in  the  midline  is  45  mm.  It  narrows  toward  the  outer 
ends.  The  anterior  margin  is  nearly  straight,  and  the  bone  is  12  mm.  thick  in  most  of  its  parts. 
The  anterior  portion  of  the  upper  surface  is  occupied  by  a  smooth  band  running  from  the  one 
extremity  to  the  other.  The  outer  ends  of  the  costal  plates  are  ornamented  with  pits  and 
furrows  varying  from  2  mm.  in  diameter  near  the  free  border  to  5  mm.  away  from  the  border. 
These  are  arranged  mostly  in  rows  parallel  with  the  free  border  of  the  costal.  Elsewhere  the 
pits  are  irregularly  distributed. 

In  1902,  Dr.  W.  D.  Matthew  and  Mr.  Walter  Granger,  employed  by  the  U.  S.  Geological 
Survey,  collected  at  Opal,  Wyoming,  two  nearly  complete  carapaces  of  a  trionychid  which  is 
without  doubt  identical  with  Cope's  Bridger  specimen.  These  deposits  at  Opal  belong  to  the 
lowest  of  the  Bridger  formation.  Fig.  i,  plate  99,  shows  the  form  of  the  better  specimen.  A 
study  of  these  and  a  specimen  obtained  for  the  American  Museum  of  Natural  History  by 
Messrs.  Granger  and  Sinclair,  in  1905,  have  convinct  the  writer  that  it  is  better  to  describe 
them  under  a  new  name  than  to  follow  Cope's  example  of  assigning  them  to  A.  radula,  a 
species  from  the  Wasatch. 

This  was  an  exceedingly  large  turtle,  the  length  of  the  better  carapace  from  Opal  (plate 
99,  fig.  i;  text-fig.  672),  along  the  midline,  being  431  mm.  and  the  width,  greatest  slightly 
behind  the  middle  of  the  length,  400  mm.,  not  including  the  extension  of  the  ribs  beyond 
the  border  of  the  shell.  The  carapace  was  only  slightly  convex,  with  a  slight  longitudinal 
depression  in  the  central  portions.  Anteriorly  and  posteriorly  the  carapace  is  truncated,  with 
the  result  of  making  it  appear  nearly  square.  The  anterior  border  of  the  nuchal  bone  is 
especially  straight.  Its  size  and  appearance  is  almost  identical  with  that  of  Cope's  Bridger 
specimen  and  needs  not  to  be  described.  Its  distal  ends  lie  above  the  contiguous  parts  of  the 
first  costals;  and  there  are  no  fontanels  behind  the  nuchal.  There  are  eight  neural  plates, 
there  being  one  which  appears  to  belong  to  the  eighth  pair  of  neurals,  an  unusual  thing.  Of 
these,  the  first  is  the  largest  and  the  eighth  the  smallest.  A  view  of  the  figure  will  show  that 
there  exist  various  irregularities  in  the  forms  of  the  neurals  and  costals.  The  first  neural  has 
a  length  of  70  mm.  and  a  width  of  55  mm.;  but  the  second  specimen  has  a  smaller  neural, 
the  anterior  end  of  which  is  not  so  broad  as  the  posterior.  The  third  neural  of  the  large  speci- 
men is  50  mm.  long  and  39  mm.  wide. 

It  will  be  observed  that  the  seventh  neural  is  heart-shaped  and  is  brought  foi-ward  so  as  to 
lie  partly  between  the  costals  of  the  sixth  pair.  The  eighth  neural  is  very  small,  12  mm.  long 
and  19  mm.  wide,  and  lies  between  the  seventh  costals.  The  eighth  pair  of  costals  measure 
fore  and  aft,  44  mm.  and  from  side  to  side,  taken  together,  136  mm.  As  an  individual 
peculiarity,  the  right  one  is  much  the  larger. 

The  borders  of  the  shell  are  beveled  off  obliquely  at  the  sides,  and  nowhere  does  the  super- 
ficial layer  overhang  the  ribs.  Posteriorly  the  edge  of  the  shell  is  rounded.  The  ribs  project 
beyond  the  shell  about  30  mm.,  and  these  projecting  ends  are  25  mm.  or  more  wide.  At  their 
sutural  borders  the  costal  plates  are  about  8  mm.  thick. 

As  stated,  there  is  a  smooth  band  along  the  front  of  the  nuchal  bone.  In  the  central 
portions  of  the  shell  (plate  99,  fig.  2)  the  ornamentation  consists  of  large  shallow  pits  sur- 
rounded with  a  low  narrow  wall.  Here  the  pits  average  about  5  mm.  in  diameter.  As  the 
outer  ends  of  the  costals  (same  plate,  fig.  3)  are  approacht,  the  pits  become  slightly  smaller 
and  are  arranged  more  or  less  in  rows  which  are  parallel  with  the  free  border  of  the  costal. 
There  may  be  as  many  as  six  pits  in  a  line  20  mm.  long.  Here  also  the  walls  show  a  tendency 
to  break  up  into  short  ridges  and  tubercles.  At  the  end  of  the  plates  there  is  a  smooth  band 
from  18  to  25  mm.  wide. 

The  vertebral  column  is  strongly  developt,  as  shown  by  fig.  673. 

The  second  specimen,  from  Opal,  is  greatly  like  the  one  just  described;  but  the  greatest 
width  is  slightly  further  forward  and  the  hinder  border  is  not  so  squarely  truncated. 

The  specimen  collected  by  Messrs.  Granger  and  Sinclair  at  the  mouth  of  Big  Sandy 
Creek,  Wyoming,  No.  3938  of  the  American  Museum,  resembles  in  essential  particulars  the 
carapaces  just  described,  but  it  appears  even  flatter  than  these.  The  length  is  450  mm.,  the 
breadth,  370  mm.  The  ribs  projected  beyond  the  free  margins  at  least  30  mm.  There  is 
a  broad  smooth  band  around  the  border,   except   in    the    rear.     The    ridges    surrounding 


TRIONYCHIDv*;. 


519 


the  pits  are  broad  and  rounded.  The  pits  measure  as  in  the  Opal  specimens.  Usually 
there  are  5  of  them  in  a  line  20  mm.  long,  but  sometimes  as  many  as  6  and  again  as  few  as  4. 
The  thickness  of  the  second  neural  is  8  mm.;  that  of  the  sutural  border  of  the  second  costal, 

near  the  distal  end,  7  mm.;   that  thru 
°72-  075.  j.]^g   middle  of  the  width  of  the  same 

costal,  13  mm. 

Too  little  is  known  regarding  Cope's 
Trionyx  radulus,  originally  found  in 
the  Wasatch  beds  of  New  Mexico,  to 
identify  the  Bridger  specimens  as  the 
same.  In  the  Wasatch  specimens  the 
smooth  beveled  band  around  the  free 
border  is  much  narrower  than  in  the 
Bridger  carapaces,  the  ridges  of  the 
sculpturing  coming  down  in  places  close 
to  the  edge.  In  the  case  of  the  costal  of 
Cope's  fig.  13  the  border  near  the  pro- 
jecting rib  is  cut  off  nearly  square,  with 
a  tendency  of  the  upper  layer  to  over- 
hang. Nothing  of  this  sort  is  seen  in 
any  of  the  Bridger  specimens.  The 
costals  and  the  neurals  of  the  Bridger 
forms  appear  to  be  thicker  than  those 
of  the  type  of  A.  radula.  The  pits  of 
the  latter,  too,  are  smaller,  there  being 
usually  6  in  a  20  mm.  line,  instead  of  5. 
The  ribs  of  y^.  radula  do  not  stand  out 
so  prominently  on  the  under  side  of  the 

,         ,;_  A-         ^      J  o  r  vx  1       costals  as  they  do  in  the  specimens  of 

fiGS.  072  AND  07^. — Amyda  tequa.   Carapace  of  type.  X  J.        a 

A.  aqua. 

672.  Carapace.  The  specimen  (plate  99)  belonging 

673.  Vertebra  of  carapace    seen   from  below      c.p.  z,cp.  8  rib-heads       ^^  jj^^  y.  S.  National  Museum  is  taken 

of  second,  and  eighth  costal  plates;   dor.v.  2,  dor.v,  8,  second 

and  eighth  dorsal  vertebra;;  nu.p.,  nuchal  plate.  as  the  type  of  A.  tequa. 


Amyda  uintaensis  (Leidy). 
Plate  100,  fig.  1;    text-figs,  674,  675. 

Trionyx  uintaensis,  Leidy,  I'roc.  Acad.  Nat.  Sci.  Phila.  1872,  p.  267;  Contrib.  F2xt.  Vert.  Fauna  West. 

Terrs.,  1873,  pp.  178,  342,  plate  xxix,  fig.  i. — Cope,  Vert.  Tart.  Form.  West.  1884,  p.  118;  Contrib. 

Canad.  Palsont.,  11,  1891,  p.  5. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  454. 
Amyda  uintaensis,  Hay,  Amer.  Geologist,  xxxv,   1905,  p.  336. 

The  present  species  was  based  on  a  nearly  complete  carapace  which  was  procured  by  Dr. 
Leidy  during  his  stay  at  Fort  Bridger,  in  the  year  1872.  It  was  found,  it  is  stated,  in  the 
Bridger  deposits,  at  Dry  Creek,  about  lo  miles  from  Fort  Bridger.  It  is  probable  that  Little 
Dry  Creek  was  meant.    If  so,  the  level  is  B.    This  specimen  belongs  to  the  Academy  of  Natural 

Sciences  of  Philadelphia,  where  the  writer  has  been  permitted 
to  study  it.  Originally  little  more  than  fragments  were  missing 
from  the  right  side,  altho  the  left  side  was  more  damaged. 
Now,  however,  it  lacks  the  nuchal,  which  was  originally  present. 
The  specimen  was  kindly  loaned  to  the  writer  with  permission  to 
develop  it  further,  and  the  result  has  been  to  find  present  most  of 
the  plastron  and  some  of  the  cervical  vertebrae. 

The  carapace  (fig.  674)  is  nearly  as  broad  as  long,  broadest 

somewhat  behind  the  middle  of  the  length,  very  slightly  concave 

in  outline  near  the  middle  of  the  front,  sinuous  along  the  sides,  and  truncated  behind.    As 

stated  by  Dr.  Leidy,  the  carapace  is  about  as  convex  as  that  oi  Platypeltis  muttca.    The  length 


Neural. 

Length. 

Width. 

58 

33 

X 

46 

3' 

3 

46 

J7 

4 

42 

21 

5 

38 

^5 

6 

^4 

^3 

520 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


is  420  mm.  and  the  maximum  width  394  mm.  There  are  8  pairs  of  costal  plates  and  6  neurals. 
The  nuchal  extended  from  side  to  side  240  mm.,  and  from  front  to  back  56  mm.  There  is 
no  fontanel  behind  the  nuchal.  The  neurals  are,  in  general,  rather  narrow.  The  anterior  two 
are  coffin-shaped,  with  the  narrow  end  directed  forward;  the  next  two  are  nearly  quadri- 
lateral; the  fifth  coffin-shaped,  with  the  broad  end  forward,  while  the  sixth  is  cordate  and 
much  reduced  in  size.    The  table  presents  the  length  and  the  maximum  breadth  of  the  neurals. 

Of  the  costal  plates,  the  first  is  broader  than  any  of  the  others  at  the  proximal  end.  The 
second  and  the  sixth  are  wider  than  any  others  at  the  distal  end.  The  eighth  is  very  short  in  all 
directions.  On  account  of  the  absence  of  the  seventh  and  eighth  neurals  and  the  reduction  of 
the  sixth,  the  three  hindermost  pairs  of  costals  meet  in  the  midline.  The  rib  of  the  fourth 
right  costal  is  present  and  projects  beyond  the  border  of  the  costal  about  30  mm.,  being  28  mm. 
wide  at  the  base.  Similar  ribs  have  extended  beyond  the  other  costal  plates,  except  the  seventh 
and  the  eighth.     The  costal  plates  are  about  5  mm.  thick. 

The  sculpture  resembles  that  of  Aspideretes  guttatus  but  is  coarser.  There  are  from  4  to 
7  pits  in  20  mm.,  usuallj;  five,  the  pits  being  quite  irregular  in  size  and  grouping.  From  their 
summits  the  walls  between  the  pits  slope  gradually  to  the  bottoms  of  the  latter. 


Figs.  674  and  675. — Amyda  uintaensis.     Carapace  and  plastron  of  type.     X  l- 

674.  Carapace. 

675.  Plastron.     cer.v.(>,  cer.v.%,  silth  and  eighth  cervical  vertebrae;    ent,  entoplastron;    l^pi,  r.epi,  left  and  right 

epiplastron;   Lhyo,  r.hyo,  left  and  right  hyoplastron;   r.hypo,  right  hypoplastron. 

The  hyoplastron  and  the  hypoplastron  of  the  right  side  are  complete,  excepting  that  the 
extremities  of  the  external  processes  are  broken  away  (plate  100,  fig.  i;  text-fig.  675).  On 
the  left  side  there  remains  only  a  fragment  of  the  hyoplastron.  The  right  and  the  left  branches 
of  the  entoplastron  are  present,  but  the  median  and  anterior  part  is  missing.  On  the  right  side 
is  seen  the  anterior  portion  of  the  epiplastron,  while  the  posterior  part  of  the  left  epiplastron 
lies  close  to  the  corresponding  part  of  the  entoplastron. 

Judging  from  the  fragments  of  these  parts  of  the  plastron  that  remain,  the  entoplastron 
and  the  epiplastra  were  not  especially  different  from  those  o( Platypeltis  ferox. 

The  hyoplastron  is  not  co-ossified  with  the  hypoplastron.  The  suture  is  directed  inward 
and  forward,  so  that  the  anterior  bone  is  narrower  than  the  one  behind  it.  The  greater  portion 
of  these  bones  is  covered  with  a  large  callosity.  This  is  ornamented  on  the  external  ends  of 
the  bones  with  pits  which  resemble  those  of  the  carapace,  but  are  not  so  large,  there  being 
about  five  in  a  line  10  mm.  long.  The  inner  ends  of  the  bones  are  smooth,  but  display  a  cloth- 
like texture,  produced  by  interwoven  fibers  of  bone. 


TRIONYCHID^-. 


521 


The  xiphiplastra  are  missing;  but  the  notches  in  the  right  hypoplastron  show  that  these 
bones  were  articulated  as  in  Platypeltis. 

Three  cervical  vertebrae  were  exposed  in  preparing  the  plastron,  the  sixth,  seventh,  and 
eighth.  All  of  these  are  turned  backward,  as  if  the  head  had  been  retracted  within  the  shell. 
The  sixth  has  a  length  of  75  mm.    The  structure  of  these  vertebrae  resembles  that  of  P.  ferox. 

There  is  present  also  one  ilium,  but  there  appears  to  be  nothing  distinctive  about  it. 

This  species  is  very  distinct  from  Asptderetes  guttatus,  but  it  might  be  very  difficult 
to  distinguish  small  fragments  of  the  two.  The  last-named  species  has  a  much  more  elongated 
shell  and  a  preneural,  characters  which  readily  distinguish  it  from  Amyda  uinta'ensis.  From 
AmyJa  egregia,  which  has  similar  ornamentation,  it  is  distinguish!  by  the  different  form  of 
the  carapace  and  of  the  first  neural;  by  the  narrower  neurals;  and  by  the  presence  ot  6, 
instead  of  7,  of  them. 

Amyda  scutumantiquum  Cope. 

Plate  100,  figs.  2-4;    plate  loi,  fig.  i;   text-figs.  676,  677. 

Trionyx  scutumantiquum,  CoPE,  6th  Ann.  Report  U.  S.  Geol.  Surv.  Terrs.,  1872  (187^),  p.  617;  Amer. 

Naturalist,  xvi,  1882,  p.  988,  fig.  6;    Vert.  Tert.  Form.  West,  1884,  pp.  118,  121,  plate  xvi,  figs. 

I,  la. — Hay,  Bibliog.  and  Cat.   Foss.  Vert.  N.  A.,   1902,  p.  454. 
Amyda  scutumantiquum,  Hay,  Amer.  Geologist,  xxxv,  1905,  p.  336. 

The  type  of  this  species  consists  of  a  nearly  complete  carapace  and  a  considerable  part  of 
the  plastron,  which  were  found  in  the  Bridger  beds,  on  Cottonwood  Creek,  in  Wyoming.  This 
specimen  is  now  in  the  American  Museum  of  Natural  History  and  has  the  number   1035. 


Figs.  676  and  677. — Amyda  scutumantiquum.    X  ;,■ 

676.  Carapace. 

677.  Plastron.    Restored  mostly  from  left  half, 

partly  from  right. 


Professor  Cope  also  referred  to  the  same  species,  with  some  doubt,  fragments  which  had  been 
collected  from  the  Wasatch  deposits  near  Black  Butte,  Wyoming,  and  from  the  same  forma- 
tion on  Bear  River.  Where  these  Wasatch  specimens  now  are  the  present  writer  does  not 
know. 

On  the  page  facing  plate  xvi  of  the  Vertebrata  of  the  Tertiary  Formations  of  the  West, 
Professor  Cope  states  that  his  figures  of  this  species  are  reduced  to  one-fourth  the  size  of  nature; 
but  this  is  an  error,  the  figures  being  almost  exactly  one-third  the  natural  size. 

This  species  attained  a  large  size  and  possest  a  heavy  shell.  The  length  of  the  carapace 
(plate  loi,  fig.  i;  text-fig.  676)  of  the  type  is  430  mm.,  measuring  from  the  anterior  portion 
of  the  nuchal.    The  width  is  very  close  to  400  mm.    There  was  probably  a  broad  but  very 


522  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

shallow  sinus  in  the  anterior  border  of  the  carapace.  The  rear  is  broadly  rounded.  The  shell 
was  considerably  archt  from  the  lateral  borders  to  beyond  the  middle  of  the  costal  plates,  the 
rise  being  about  82  mm.    Along  the  middle  of  the  back  there  is  a  rather  deep  depression. 

The  nuchal  extended  on  each  side  of  the  midline  at  least  152  mm.,  and  was  37  mm.  wide 
fore  and  aft,  perhaps  somewhat  more  at  the  midline.  There  was  no  fontanel  between  it  and 
the  costals  of  the  first  pair  and  the  first  neural.  Also  there  was  no  preneural.  The  first  neural 
is  large,  being  68  mm.  long  and  T,y  mm.  wide  posteriorly.  The  others  diminish  in  size  to  the 
seventh  and  last.  The  second  and  third  are  coffin-shaped,  the  next  three  nearly  quadrilateral, 
and  the  last  heart-shaped.  This  last  one  is  only  22  mm.  long  and  wide,  and  it  separates  only 
partly  the  seventh  costals. 

All  the  costals  grow  broader  toward  their  outer  ends,  except  the  first  and  the  last  pairs. 
Those  of  the  eighth  pair  are  united  in  the  midline  by  their  entire  width,  and  by  their  free 
borders  they  form  125  mm.  of  the  hinder  margin  of  the  shell.  At  their  free  ends  the  most  of 
the  costals  are  beveled  off  to  a  sharp  edge,  except  where  the  rib  projects  beyond  the  costal 
plate.  Posteriorly  the  edge  of  the  carapace  is  more  obtuse.  Near  their  outer  ends  the  costals 
are  about  9  mm.  thick  at  the  sutural  border,  and  12  mm.  thru  the  rib.  How  far  the  ribs 
extended  beyond  the  borders  of  the  costal  plates  can  not  now  be  determined.  Near  the  outer 
ends  of  the  costals  the  ribs  occupy  nearly  half  the  width  of  the  lower  surface  of  the  plates. 

The  nuchal  had  a  broad,  smooth  band  along  its  front,  and  this  band  has  continued  around 
the  greater  part  of  the  carapace,  becoming  very  narrow  behind.  The  sculpture  (plate  100, 
figs.  3,  4)  consists  of  the  usual  pits  and  ridges,  the  pits  being  rather  deeply  imprest  and  the 
ridges  abrupt.  There  are  2  or  3  pits  in  10  mm.  They  are  large  and  distinct  in  the  median 
depression  (fig.  3)  of  the  shell  and  on  the  middle  of  the  length  of  the  costals,  smaller  on  the 
highest  part  of  the  carapace  and  on  the  outer  ends  (fig.  4)  of  the  costals.  As  the  smooth  band 
is  approacht,  there  is  a  tendency  in  the  ridges  to  break  up  into  tubercles.  In  figs.  3  and  4  of 
plate  100  the  upper  edge  of  the  figure  is  that  directed  toward  the  head  of  the  animal. 

Besides  the  carapace.  Cope  figured  the  outer  ends  of  the  hyoplastral  and  hypoplastral 
bones  of  the  right  side;  but  the  same  bones  of  the  left  side,  nearly  complete,  are  present  (fig. 
677).  The  length  of  the  suture  joining  them  is  185  mm.  The  antero-posterior  width  of  the 
hyoplastron  at  the  inner  end  was  about  90  mm.;  that  of  the  narrowest  part,  across  the 
bridge,  35  mm.  The  antero-posterior  extent  of  the  inner  border  of  the  hypoplastron,  exclusive 
of  the  processes,  was  95  mm.,  that  of  the  narrowest  part,  28  mm. 

The  thickness  of  the  plastron  at  the  inner  ends,  between  the  ridges  of  bone  which  ter- 
minate in  the  digitations,  is  9  mm.  Thru  the  thickest  part  of  the  bridge  the  bone  measures 
15  mm. 

The  lower  surface  of  the  bone  is  ornamented,  next  to  the  outer  end  of  the  bridge,  with 
sharp  ridges  running  antero-posteriorly.  At  the  inner  ends  of  the  bones  the  surface  is  covered 
with  sharp  tubercles.    The  remainder  of  this  surface  is  merely  roughened. 

Amyda  concentrica  (Cope). 
Plate  98,  figs.  7-10. 

Trionyx  concentricus.  Cope,  Palaeont.  Bull.  No.  I,  1872,  p.  461;  Proc.  Anier.  Philos.  Soc,  xil,  1873, 
p.  461;  U.  S.  Geol.  Surv.  Terrs.,  1872  (1873),  p.  617;  Vert.  Tert.  Form.  West,  1884,  pp.  118,  120, 
plate  xvi,  figs.  3-6. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  454. 

Amyda  concentricus,   Hay,  Amer.  Geologist,  xxxv,   1905,  p.  336. 

The  type  of  this  species  consists  of  4  fragments  of  costal  plates,  3  of  which  belong  to  the 
proximal  ends,  and  i  to  the  distal  end,  of  their  respective  plates.  These  were  found  in  the 
Bridger  deposits  along  Cottonwood  Creek,  Wyoming.  In  his  earliest  description  Professor 
Cope  states  that  the  remains  of  this  species  are  common  in  the  Bridger  beds;  but  the  present 
writer  knows  of  no  specimens  except  the  types.  These  are  now  in  the  American  Museum 
of  Natural  History  and  have  the  catalog  number  1049. 

The  animal  to  which  the  type  costals  belonged  was  a  small  one,  probably  about  160  mm. 
in  length  of  carapace.  The  average  width  of  the  four  costals  is  19  mm.  The  thickness  thru 
the  sutural  borders  is  3  mm.;  thru  the  ribs  it  is  4  mm.  The  sculpture  appears  to  furnish 
characters  for  the  identification  of  the  species.    On  the  proximal  ends  of  the  costals  the  pits 


TRIONYCHID^. 


523 


are  usually  large,  there  being  2  in  a  line  10  mm.  long;  but  on  the  distal  ends  there  may  be  3 
or  4  pits  in  this  distance.  These  pits  are  arranged  in  somewhat  irregular  rows  across  the 
costal  bones.  Some  of  the  ridges  separating  these  rows  are  higher  and  have  sharper  summits 
than  the  others,  these  more  conspicuous  ridges  running  across  the  costals  at  a  distance  ot 
about  10  mm.  apart.  There  may  thus  be  from  I  to  4  rows  of  pits  between  each  two  of  these 
larger  ridges. 

Amyda  franciscae  sp.  nov. 

Plates  102,  103;    text-figs.  678,  679. 

The  fine  specimen  to  which  the  name  Amyda  franciscce  is  given  was  collected  by  Mr. 
Walter  Granger,  of  the  American  Museum  expedition  of  1903,  in  the  Bridget  beds  of  Wyoming. 
The  exact  locality  is  the  eastern  part  of  the  Grizzly  Buttes;  the  level  is  that  known  as  B.  The 
specimen  consists  of  the  complete  carapace  and  plastron;  the  seventh  and  eighth  cervical 
vertebras;  both  scapulae  and  both  coracoids;  the  pelvis,  mostly  hidden  by  the  xiphiplastrals; 
the  proximal  ends  of  both  humeri;  most  of  the  right  hind  leg;  the  left  femur;  and  most  of 
the  left  hind  foot.    The  catalog  number  of  the  type  is  5936. 


678. 


Figs.  678  and  679. — Amyda  franciscce.     X  J. 

678.  Carapace. 

679.  Plastron,    ent^  entoplastron;    epi^  epiplastron;    hyo^  hyoplastron; 

hypo,  hypoplastron;    xiph,  xiphiplastron. 

In  form  the  carapace  (plate  102;  text-fig.  678)  is  broadly  elliptical,  slightly  truncated  in 
front  and  more  decidedly  truncated  behind.    Antero-posteriorly  the  carapace  is  slightly  archt; 

more  strongly  from  side  to  side.    The  length  in  a  straight  line  is 
315  mm.;   the  greatest  width  is  293  mm. 

This  species  is  referred  to  the  genus  Amyda  because  of  the 
presence  of  8  pairs  of  costals  and  the  absence  of  a  preneural. 
There  are  7  neurals,  of  which  the  first  is  very  large  and  the 
seventh  much  reduced.  The  anterior  neural  is  considerably 
broader  in  front  than  behind.  The  table  herewith  presents  the 
dimensions  of  the  neurals.  The  four  neurals  succeeding  the 
first  are  wider  behind  than  in  front;  the  next  two  are  wider  in 
front  than  behind. 

The  nuchal  has  a  fore-and-aft  extent  of  36  mm.,  and  is  about 
130  mm.  from  side  to  side.  The  anterior  border  of  the  bone  is  occupied  by  a  narrow,  smooth 
band.  There  appears  to  have  been  a  small  median  fontanel  between  the  nuchal  and  the 
first  neural. 

The  form  and  therelative  proportions  of  the  costal  plates  maybe  seen  from  the  illustrations. 
Their  free  borders  are  beveled  off  to  an  acute  edge.    The  costal  ribs  are  broad  and  they  project 


Neurals. 

Length. 

Greatest 
width. 

55 

35 

44 

»9 

40 

19 

34 

^4 

3' 

19 

28 

'7 

7 

i? 

17 

524  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

beyond  the  margin  of  the  carapace  about  30  mm.  The  thickness  of  the  costals,  measured  at 
the  sutures,  is  about  8  mm.;  measured  thru  the  ribs  it  is  about  13  mm.  The  costals  of  the 
seventh  and  the  eighth  pairs  meet  their  fellows  along  the  midline.  Those  of  the  eighth  pair 
are  rather  small. 

The  sculpture  of  the  carapace  is  of  median  coarseness,  there  being  about  3  pits  in  a  line 
ID  mm.  long.  The  pits  are  shallow  and  the  rounded  walls  surrounding  them  are  about  as 
wide  as  the  pits.    For  some  distance  on  each  side  of  the  midline  the  sculpture  is  nearly  obsolete. 

The  plastron  (fig.  679)  incloses  large  median  fontanels.  The  entoplastron  and  the  epi- 
plastra  are  slender  bones,  resembling  those  ai  Platypeltis  sptnifera.  They  possess  no  "cal- 
losities." Nearly  the  whole  surface  of  the  hyoplastra  and  the  hypoplastra  is  furnisht  with  pits 
and  ridges,  but  these  are  not  so  coarse  as  those  of  the  carapace,  there  being  about  five  pits  in  a 
line  10  mm.  long.  These  are  better  developt  on  the  outer  ends  of  the  bones  mentioned.  The 
median  borders  of  these  bones  show  a  band  consisting  of  a  network  of  bony  fibers.  The 
surfaces  of  the  xiphiplastra  present  a  similar  interlacement  of  bony  fibers. 

The  width  of  the  bridge,  where  narrowest,  is  51  mm.,  of  which  26  mm.  belong  to  the 
hypoplastron.  The  median  border  of  this  bone  possesses  about  ten  digitations,  of  which  the 
two  posterior  are  the  largest  and  receive  between  them  the  inner  process  of  the  xiphiplastron. 
The  xiphiplastra  are  slender  bones.  They  join  each  other  by  means  of  anterior  two-tootht 
processes  and  by  broad  posterior  processes. 

The  bones  belonging  to  the  vertebral  column,  the  shoulder  and  pelvic  girdles,  and  the 
limbs  present  no  peculiarities. 

This  species  resembles  in  some  respects  Amyda  utnta'ensis  Leidy.  It  differs,  however,  in 
being  more  elliptical  in  outline,  in  having  the  greatest  width  nearer  the  middle  of  the  length, 
7  neurals  instead  of  6,  a  differently  formed  first  neural,  a  sculpture  finer  and  of  different 
character,  and  a  narrower  plastral  bridge,  of  which  the  hypoplastron  is  wider  than  the  hyo- 
plastron. 

Dedicated  to  the  writer's  daughter.  Miss  Frances  Steele  Hay. 

Amyda  salebrosa  sp.  nov. 

Plate  104,  fig.  i;   text-fig.  680- 

Amyda  salebrosa  is  based  on  a  specimen  which  was  collected  by  Mr.  Walter  Granger  at 
Dry  Creek,  in  southwestern  Wyoming,  June  30,  1904.  The  level  at  which  it  was  found  is  C, 
the  middle  of  the  Bridger  deposits.  Only  the  carapace  is  present,  but  this  is  practically  com- 
plete.    It  bears  the  number  3941  of  the  American  Museum's  catalog. 

The  carapace  (plate  104,  fig.  i;  text-fig.  680)  was  broad  and  probably  rather  flat.  The 
front  margin  is  broadly  rounded,  the  rear  truncated.  The  length  is  425  mm.;  the  greatest 
width,  455  mm.  Considering  the  great  size  of  the  carapace,  it  is  rather  thin,  being  only  8  mm. 
thick  at  the  sutural  borders,  near  the  ends  of  the  costals.  Thru  the  ridges  on  the  underside 
of  the  carapace,  produced  by  the  ribs,  the  thickness  is  12  mm.  The  outer  ends  of  the  costals 
are  beveled  off  from  above. 

The  nuchal  has  a  lateral  extent  of  267  mm.,  and  a  fore-and-aft  extent  of  57  mm.   Its  whole 

upper  surface  is  pitted.    Its  outer  ends  overlap  the  outer  anterior 
angles  of  the  first  costals. 

There  are  7  neural  plates,  and  these  decrease  in  size  from  the 
first  to  the  last.  The  accompanying  table  gives  the  dimensions. 
The  first  neural  is  hexagonal,  with  the  short  sides  consisting 
of  the  posterior  and  the  two  postero-lateral.  The  next  two 
neurals  have  the  narrow  end  directed  forward;  the  fourth  is 
nearly  a  parallelogram;  the  fifth  and  the  sixth  have  the  wider 
end  in  front;  the  seventh  is  pentagonal.  The  costals  of  the 
seventh  pair  join  in  the  midline  behind  the  seventh  neural. 
Those  of  the  eighth  pair  met  along  the  midline  for  a  distance  of 
about  30  mm.;  and  each  had  a  lateral  extent  of  about  48  mm.  The  distal  ends  of  the  ribs  pro- 
ject but  little  beyond  the  borders  of  the  disk.  In  younger  specimens  they  will  doubtless  be 
found  to  project  a  greater  distance. 


Neural. 

Length. 

Width. 

67 

38 

55 

35 

48 

3> 

45 

26 

37 

21 

6 

33 

^4 

7 

26 

22 

TRIONYCHID^. 


525 


Fig.  680. — Amyda  salebrosa.   Cara- 
pace of  type.     X  i- 


The  sculpture  of  this  species  presents  a  rather  pecuHar  appearance,  being  coarse,  irregular 
and  rough.    The  pits  are  irregular  in  size,  form,  in  height  of  bounding  walls,  and  in  disposition 

with  reference  to  each  other.  On  the  central  portion  of 
the  disk,  including  the  greater  part  thereof,  there  are  from 
2  to  5  pits  in  a  line  20  mm.  long.  Around  the  borders 
of  the  carapace  the  pits  are  slightly  smaller  than  else- 
where, but  often  not  well  defined.  Everywhere  the  walls 
separating  the  pits  are  rather  sharp  and  of  varying  height, 
often  being  lifted  up  into  sharp  points,  especially  in  the 
angle  formed  by  the  junction  of  three  pits. 

This  species  is  sufficiently  different  from  all  others 
yet  found.  A spideretes  guttatus,  A.  ellipticus,  and  A. 
granger!  all  have  much  more  elongated  carapaces. 
Amyda  egregia  has  a  thicker  carapace,  a  smoother  sculp- 
ture, and  a  nuchal  less  extended  laterally.  In  A.  scutum- 
antiquum  the  carapace  is  more  elongated,  the  nuchal  is 
furnisht  with  a  smooth  band,  and  the  sculpture  is  every- 
where finer.  In  A.  radula  the  nuchal  is  nearly  straight 
in  front. 

It  is  A.  utntaensis  to  which  the  present  species  is 
most  closely  related.  It  differs  from  the  latter  in  having 
the  greatest  width  of  the  shell  in  front  of  the  middle  ot 
the  length;  in  having  a  more  convex  front;  and  in 
having  larger  and  more  irregular  pits.  The  types  of 
the  two  species  are  of  almost  exactly  the  same  length 
and  may  therefore  be  more  readily  compared.  A.  scutumanttquum  is  longer  than  broad; 
A.  salebrosa  is  broader  than  long. 

Amyda?  exquisita  sp.  nov. 
Text-figs.  681-683. 

This  species  is  represented  in  the  American  Museum  of  Natural  History  by  portions  of  2 
individuals,  which  were  collected  in  the  Bridger  beds  of  the  Grizzly  Buttes,  Wyoming,  by  the 
museum's  expedition  of  1903.  Of  these  specimens,  number  5923  is  taken  as  the  type.  It  con- 
sists of  the  carapace  (fragmentary  but  representing  well  the  structure),  the  hyoplastra  and 
hypoplastra  of  both  sides  somewhat  damaged,  one  cervical  vertebra,  portions  of  both  humeri, 
the  left  femur,  portions  of  the  pelvis,  and  various  other  leg  and  foot  bones.  Of  the  other 
individual.  No.  5943,  there  are  present  only  the  hyoplastron  and  the  hypoplastron  of  the 
right  side. 

This  species  is  markt  among  the  species  of  the  genus  found  in  the  Bridger  beds  by  the 
thinness  of  the  shell  and  the  coarseness  of  the  sculpture.  The  total  length  of  the  carapace 
(fig.  681)  was  very  close  to  375  mm.;  the  greatest  width  almost  the  same.  Evidently  the  out- 
line, both  in  front  and  behind,  was  slightly  concave;  laterally  it  is  sinuous.  The  disk  was 
filled  out  nearly  to  the  ends  of  the  ribs. 

The  thickness  of  the  sutural  border  of  the  third  costal  plate,  near  the  proximal  end,  is 
6  mm.;  but  thinner  toward  the  distal  end  of  the  plate.  Thru  the  rib,  in  the  middle  of  the 
width  of  the  costal,  the  thickness  amounts  to  9  mm.  The  sutural  border  of  the  eighth  costal 
is  y  mm.  thick. 

The  exact  dimensions  of  the  nuchal  bone  can  not  be  determined,  there  remaining  only  2 
fragments;  but  evidently  the  lateral  extent  of  the  bone  was  close  to  250  mm.,  and  the  fore-and- 
aft  extent,  at  the  midhne,  very  close  to  50  mm.  Fig.  682  represents  a  section  of  the  bone  along 
the  midline.  The  free  border  is  reduced  to  a  subacute  edge.  Seen  from  above,  the  nuchal 
presents  a  smooth  band  along  the  anterior  border.  This  is  13  mm.  wide  at  the  midline, 
but  increases  to  twice  this  width  toward  the  distal  ends.  The  maximum  thickness  of  the  bone 
is  about  13  mm. 

From  the  materials  at  hand  it  can  not  be  certainly  determined  whether  there  was  a  pre- 
neural  bone;   but  probably  this  was  absent.    There  are  7  neurals,  the  dimensions  of  which  are 


526 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


given  in  the  table  below.  Of  these  neurals,  the  anterior  was  probably  about  as  wide  in 
front  as  behind.  The  next  three  have,  as  usual  in  the  family,  the  narrower  end  directed  for- 
ward. The  fifth  has  the  anterior  end  only  slightly  narrower  than  the  hinder  end.  The  sixth 
has  the  broader  end  in  front.    The  seventh  is  heptagonal. 

At  the  free  border  the  costals  are  beveled  off  on  the  upper  side. 


Figs.  681-683. — Amyda?  exquisita.     Type. 

681.  Carapace.    XJ.    Parts  ruled  with  parallel  lines  are  missing. 
682.  Antero-posterior  median  section  of  nuchal.    Xi.  683.  Plastron.    X5. 

On  most  portions  of  the  carapace  the  sculpture,  consisting  of  pits,  is  coarse.    The  bottoms 
of  the  pits  slope  up  to  the  summits  of  the  rounded  walls.    The  average  diameter  is  about  5  mm. 

On  the  hinder  border  of  the  nuchal  the  pits  are  smaller,  about  5 
in  a  line  20  mm.  long.  Those  along  the  free  border,  too,  have 
this  size.  On  the  proximal  two-thirds  or  more  of  the  costals 
there  are  usually  4  pits  in  a  20  mm.  line.  On  the  hinder  third 
of  the  carapace  they  are  still  larger,  3  and  sometimes  only  2.5 
in  the  line  mentioned.  Those  on  the  anterior  4  or  5  neurals  are 
very  shallow. 

The  plastron  (fig.  683)  is  remarkable  for  the  narrowness  of 
the  bridges  and  the  depth  of  the  notch  between  the  outer  proc- 
ess of  the  hyoplastron  and  that  of  the  hypoplastron.  The 
width  of  the  bridge  is  only  47  mm.;  in  the  paratype,  No.  5943,  an  individual  apparently  as 
large  as  the  type,  the  width  is  only  39  mm.  The  size  of  the  fontanel  inclosed  between  the 
outstanding  processes  of  the  plastral  bones  mentioned  may  be  judged  from  the  accompanying 
figure.     There  were  also  extensive  fontanels  along  the  midline. 


Neural. 

Length. 

Width. 

5° 

19 

37 

3« 

35 

30 

36 

»7 

33 

21 

30 

21 

7 

21 

21 

TRIONYCHID^. 


527 


The  pits  of  the  plastral  hones  are  smaller  than  those  of  the  carapace,  about  7  in  a  20  mm. 
line.  Toward  the  mesial  border  of  the  bones  the  pits  become  obsolete  and  there  comes  into 
view  a  meshwork  of  bony  fibers  such  as  Cope  found  in  his  Axestus  byssinits  (A xestemys 
hyssina).  There  is,  however,  no  reason  for  thinking  that  the  present  species  is  identical  with 
Cope's  species  just  mentioned. 

The  cervical  vertebra  present  appears  to  be  the  sixth.  It  has  a  length  of  58  mm.  An  esti- 
mate shows  that  the  length  of  the  neck  was  about  380  mm.  The  bone  appears  to  be  slenderer 
than  the  corresponding  bone  of  a  specimen  oi  Plat  y  pelt  is  spinifera. 

The  fragmentary  bones  belonging  to  the  shoulder  and  pelvic  girdles  and  to  the  limbs 
furnish  few  noteworthy  data.  The  total  length  of  the  humerus  is  125  mm.  The  shaft  is 
slenderer  than  that  cii  A  xestemys  hyssina;  the  least  diameter  of  the  former  being  8  mm.,  that 
of  the  latter  17  mm.,  while  the  length  of  the  humerus  oi  A  xestemys  appears  not  to  have  been 
much  greater  than  that  of  the  present  species. 

This  species  is  at  once  distinguisht  from  A .  salebrosa  by  the  greater  development  of  the 
costals  of  the  two  hinder  pairs  and  by  the  greater  width  of  most  of  the  neurals.  The  greater 
breadth  of  the  carapace,  the  greater  length  of  the  nuchal  from  side  to  side,  and  the  longer 
eighth  costals  distinguish  it  from  A.  egregia.     Comparison  with  A.  concentrica  is  required. 


Amyda  mira  sp.  nov. 
Plate  105,  fig.  l;    plate  lo6;    text-figs.  684-686. 

Under  the  above  name  is  described  a  trionychid  which  was  discovered  by  the  American 
Museum  party  of  1905,  at  Grizzly  Buttes,  Wyoming,  in  level  B,  of  the  Bridger  Eocene.  The 
specimen  bears  the  number  6130.  It  furnishes  the  skull,  without  the  lower  jaw;  the  carapace 
complete;  and  the  plastron,  excepting  the  entoplastron,  the  epiplastra,  and  a  portion  of  the 
left  hyoplastron. 

The  carapace  includes  8  pairs  of  costal  plates  and  there  is  no  preneural;  hence  the  genus 
Amyda  is  indicated.  The  carapace  (plate  105,  fig.  i)  is  about  as  wide  as  long,  broadly 
rounded  behind,  more  sharply  rounded  in  front,  and  of  considerable  convexity.    The  length 

in  a  straight  line  is  263  mm.;  the  extreme  width  is  252  mm.; 
the  height  of  the  center  is  62  mm.  above  the  borders.  On  the 
sides  the  free  borders  of  the  costals  are  beveled  off;  in  front, 
the  nuchal  and  the  first  costal  are  trimmed  off  at  right  angles 
with  the  upper  surfaces. 

The  nuchal  is  27  mm.  wide,  134  mm.  from  extremity  to 
extremity,  and  97  mm.  from  its  union  on  the  free  border  with 
the  second  costal  to  the  same  point  on  the  other  side.  The 
extremities  of  this  bone  are  contained  each  between  two  plates 
of  the  second  costal. 

There  are  7  neurals,  all  except  the  first,  the  sixth,  and  the  seventh  being  hexagonal,  with 
the  broad  end  behind.    The  dimensions  are  given  in  the  table. 

Of  the  costals  the  sixth  and  the  seventh  meet  their  fellows  at  the  midline.  Those  of  the 
seventh  pair  are  well  developt.  They  join  along  the  midline  a  distance  of  30  mm.  and  each  has 
a  width  along  the  free  border  of  about  33  mm.  The  extremities  of  the  various  costals  have  a 
thickness  of  5  mm.  at  the  sutural  edges  and  of  about  8  mm.  thru  the  rib.  The  ribs  are  markt 
off  distinctly  the  full  length  of  each  costal  plate.  Those  along  the  sides  of  the  carapace  project 
about  20  mm.  beyond  the  border  of  the  disk,  but  that  of  the  eighth  costal  projected  about 
40  mm. 

The  surface  of  the  carapace  is  ornamented  with  pits  and  grooves  and  intervening  ridges. 
On  the  rear  are  10  or  12  distinct  longitudinal  welts.  The  ridges  are  narrow,  sometimes  sharp. 
The  pits  frequently  coalesce,  especially  on  the  distal  ends  of  the  costals,  to  form  grooves.  These 
show  a  tendency  to  run  parallel  with  the  axis  of  the  animal.  On  the  neurals  the  pits  are  smaller 
than  on  the  costals,  about  6  of  them  in  a  line  15  mm.  long.  On  the  proximal  ends  of  the  costals 
there  may  be  as  few  as  3  pits  in  the  given  line.  On  the  distal  ends  of  the  costals  there  are 
usually  about  5  pits  or  grooves  in  the  line  mentioned. 


Neural. 

Length. 

Width. 

, 

44 

^4 

2 

31 

13 

3 

30 

22 

4 

»7 

20 

5 

14 

18 

6 

20 

14 

7 

17 

Ig 

528 


FOSSIL    TURTLES    OF    NORTH    AMKRICA. 


The  plastron  (plate  io6,  fig.  i)  has  a  breadth,  from  the  extremity  of  the  hyoplastral 
processes  of  one  side  to  those  of  the  other,  of  about  310  mm.    The  outer  fourth  of  the  hyoplas- 

tron  of  each  side  has  coalesct  with 
the  corresponding  hypoplastron.  The 
transverse  extent  of  these  bones, 
along  this  suture,  is  133  mm.  Where 
narrowest  the  bridges  are  48  mm. 
wide.  The  hyoplastron  and  hypo- 
plastron have  a  close  resemblance 
to  those  of  Platypeltis  ferox.  The 
hypoplastron  differs  from  that  of  the 
species  just  named  in  havinga greater 
number  of  digitations  directed  toward 
the  midline. 

The  xiphiplastrals  are  concave 
along  the  outer  border,  whereas  those 
of  P.  ferox  are  convex.  In  the  latter 
species  there  is  a  single  process  which 
meets  the  single  process  from  its  fel- 
low bone;  in  A.  mira  there  is  on  the 
left  side  a  broad  process  which  is 
received  between  two  slenderer  pro- 
cesses of  the  right  side. 

Nearly  the  whole  inferior  surface 
of  the  hyoplastra,  hypoplastra,  and 
the  xiphiplastra  is  covered  with  a 
sculptured  layer  of  bone,  the  callos- 
ities, as  they  are  called  in  living  tri- 
onychid  turtles.  The  pits  and  ridges 
are  less  strongly  developt  than  on  the 
carapace.  They  are  most  distinct  on 
the  outer  ends  of  the  hyoplastra  and  hypoplastra.  Here  there  are  about  5  pits  in  a  10  mm. 
line.  On  the  mesial  halves  of  these  bones  the  pits  are  very  shallow.  The  sculpture  on  the 
xiphiplastra  is  feebly  exprest. 

The  skull  (fig.  684-686)  is  beautifully  preserved.  It  lacks  the  lower  jaw,  the  occipital 
condyle,  the  supraoccipital  process  and  parts  of  the  squamosal  processes. 

The  approximate  length  of  the  skull,  from  the  tip  of  the  snout  to  the  occipital  condyle, 
is  72  mm.;  the  greatest  width,  at  the  upper  posterior  border  of  the  tympanic  cavity,  is  45  mm. 
From  the  fronts  of  these  cavities  the  sides  of  the  skull  converge  to  near  the  narrow  and  rounded 
snout.  The  flexure  of  the  skull  behind  the  choanae  is  remarkable,  fully  as  great  as  in 
A.  cartilaginea,  while  the  descent  of  the  face  is  still  more  rapid  than  in  the  living  species 
just  named. 

The  sutures  between  the  bones  are  yet  open,  but  no  remarkable  relations  have  thereby 
been  shown.  The  tympanic  chambers  are  large,  each  diameter  being  16  mm.  The  zygomatic 
fossae  are  small,  only  14  mm.  long.  The  orbits  are  unusually  large,  the  horizontal  diameter 
being  16  mm.  equal  to  that  of  specimen  oi  Platypeltis  ferox  whose  skull  is  94  mm.  long.  The 
vertical  diameter  is  13  mm.  The  interorbital  space  is  only  4  mm.  wide.  Each  diameter  of  the 
nares  is  10  mm.    The  snout  projects  20  mm.  in  front  of  the  orbits. 

The  pterygoid  portion  of  the  palate  has  a  width  of  25  mm.  The  anterior  portion  of  the 
skull  is  remarkable  for  the  depth  of  the  groove  in  which  the  choanae  are  situated.  This  begins 
at  the  posterior  palatine  foramina  and  extends  forward  to  the  premaxills.  It  has  a  depth  of  5 
mm.  and  a  width  of  8  mm.  The  choanx  are  placed  well  backward,  the  middle  of  the  length  of 
each  being  opposite  the  middle  of  the  orbits.  Each  is  10  mm.  long.  The  triturating  surfaces 
of  the  upper  jaws  are  6  mm.  wide  opposite  the  choanae,  but  they  narrow  gradually  foi-ward. 
Altho  the  lower  jaw  is  missing  one  of  the  ceratohyals  is  preserved.  Most  of  the  internal 
skeleton  is  preserved,  but  it  has  not  been  cleared  from  the  matrix. 


Figs.  684-686. — Amyda  mira.     Skull  of  type.     X0.9. 
684.  Seen  from  above.  68j.  Lower  aspect.  686.  Right  side. 


TRIONYCHID^.  529 

This  species  resembles  in  some  respects  A.  francisca-.  However,  the  carapace  of  the  latter 
is  somewhat  excavated  at  the  midline  in  front,  the  rear  is  more  truncated,  and  the  ridges  of 
the  sculpture  have  broad  and  rounded  summits.  The  anterior  border  of  the  hyoplastron  is 
very  concave;  that  of  A.  mira  is  gently  sigmoid.  Likewise,  the  mesial  border  of  the  hypo- 
plastron  of  A .  franctscce  has  a  greater  number  of  digitations. 

There  are  points  of  resemblance  between  A.  mira  and  Platypeltis  heteroglypta.  In  the 
latter,  as  in  others  of  the  genus,  the  eighth  costals  are  wanting  or  only  feebly  developt.  The 
form  of  P.  heteroglypta  is  different  from  that  of  A .  mira,  the  front  of  the  carapace  is  more 
rounded  and  the  rear  more  truncated.  The  nuchal  is  relatively  longer  and  there  is  an 
unsculptured  band  along  its  front.  It  is  observed,  too,  that  the  ribs  on  the  underside  of  the 
costals  are  broader  in  P.  heteroglypta  than  in  the  subject  of  the  present  description.  The  width 
of  those  of  the  second,  third,  and  fourth  costals  of  P.  heteroglypta,  taken  near  the  distal  end,  is 
24  mm.  each.  In  A.  mira,  the  rib  of  the  second  is  22  mm.  wide;  the  third,  20  mm.;  the  fourth, 
18  mm.     P.  heteroglypta  was  probably  a  flatter  species,  but  the  specimens  are  much  crusht. 

Amyda?  tritor  Hay. 

Text-figs.  687-689. 

Aspidonectes  tritor,  Hav,  Science  (2),  xix,  1904,  p.  254. 
Amyda?  tritor.  Hay,  Amer.  Geologist,  xxxv,  1905,  p.  336. 

This  species  is  based  on  a  large  and  well-preserved  skull  which  was  collected  by  the 
writer  in  the  Bridger  deposits,  about  3  miles  above  the  mouth  of  Cottonwood  Creek,  east  of 
Fort  Bridger,  Wyoming.  The  matrix  in  which  the  specimen  was  found  is  a  calcareous  and 
argillaceous  sandstone  belonging  to  the  base  of  the  middle  third  of  the  Bridger  beds.  The 
number  of  the  skull,  in  the  American  Museum  catalog,  is  5913. 

The  total  length  of  the  skull  (figs.  687-689)  is  162  mm.;  and  it  has  therefore  belonged  to  a 
large  animal.  In  the  American  Museum  of  Natural  History  there  is  a  specimen  of  Platy- 
peltis ferox,  the  carapace  of  which  has  a  length  of  265  mm.  and  whose  skull  has  a  length  of  1 16 
mm.  If  the  skull  and  carapace  of  A.  tritor  had  the  same  ratio  that  obtains  in  these  parts  in 
P.  ferox,  the  carapace  of  the  former  would  have  had  a  length  of  about  370  mm.  This  is  some- 
what less  than  the  length  of  the  carapace  of  Leidy's  Trionyx  uinta'ensis,  and  considerably  less 
than  that  of  the  carapace  of  Cope's  T.  scutumantiquum.  The  skull  under  consideration  may 
therefore  have  belonged  to  one  or  the  other  of  these  or  to  some  other  described  species.  For 
the  present  it  is  necessary  to  give  a  distinct  name  to  this  skull  and  await  further  discoveries. 

The  following  are  the  principal  measurements  of  the  skull: 

Millimeters. 

Length  from  snout  to  end  of  supraoccipital  spine 162 

Length  from  snout  to  end  of  occipital  condyle 123 

Width  from  outside  to  outside  of  quadrates 91 

Width  across  pterygoids 47 

Width  of  interorbital  space 20 

In  general  form  the  skull  resembles  that  of  Platypeltis  ferox;  but  the  width  is  somewhat 
greater,  the  snout  is  shorter  and  less  pointed,  the  interorbital  space  is  broader,  and  the  choanae 
are  more  constricted.  The  facial  angle  is  about  the  same  in  the  fossil  as  in  the  living  species, 
the  roof  of  the  mouth  being  bent  down  about  25°  below  the  plane  of  the  pterygoids.  The 
sutures  between  the  various  bones  are  more  finely  dentated  than  in  P.  ferox.  The  skull 
appears  not  to  have  suffered  distortion  during  fossilization. 

The  snout  is  broad  and  blunt.  The  narial  opening  is  22  mm.  wide  and  only  12  mm.  high. 
The  co-ossified  premaxillae  are  small,  measuring  from  side  to  side  only  9  mm.  The  external 
surface  of  the  maxilla  is  perpendicular,  and  the  outline,  seen  from  above,  is  slightly  concave. 
Seen  in  profile,  the  skull  is  nearly  flat  behind  the  orbits,  whilst  more  anteriorly  there  is  a  gradual 
curve  to  the  end  of  the  snout.  In  P.  ferox  there  is  an  abrupt  change  of  direction  between  the 
hinder  borders  of  the  orbits. 

The  paroccipitals  have  about  the  same  relative  size  and  disposition  as  in  P.  ferox.     The 
portion  of  the  quadrate  exposed  between  the  prootic  and  the  squamosal  appears  to  be  some- 
what narrower  than  in  the  living  species  mentioned. 
34 


53° 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


On  the  lower  surface  of  the  skull  (fig.  688)  are  to  be  noted  the  broad  triturating  surfaces 
of  the  maxillae,  each  presenting  about  the  same  relative  amount  of  surface  as  in  P.  ferox.  The 
transition  between  the  triturating  surface  and  the  cutting-border  of  the  jaw  is  rather  abrupt. 
The  choanal  fossa  is  likewise  formed  somewhat  abruptly.  In  the  midline  in  front  ot  the 
choanae  may  be  seen  the  suture  where  the  inner  borders  of  the  maxillae  meet  below  the  vomer. 
A  portion  of  the  vomer  is  exposed  in  front  of  this  suture.  The  anterior  palatine  foramen  is 
small,  only  7  mm.  long,  while  in  the  specimen  of  P.  ferox  referred  to  above,  it  is  11  mm.  long. 


Figs.  687-689. — Amyda?  tritor.     Skull  of  type.     X  §. 
687.  View  of  upper  surface.  688.  View  of  lower  surface.  689.  View  of  right  side. 

The  choanae  are  relatively  small,  being  constricted  as  in  Amyda  carttlaginea  and  A.  sinensis, 
and  the  constriction  has  been  produced  in  the  same  manner  in  the  fossil,  as  in  living  species. 
The  basioccipital  bone  is  rather  broad,  occupying  nearly  one-third  of  the  width  of  the 
posterior  part  of  the  roof  of  the  mouth,  the  lateral  portions  being  formed  by  the  pterygoids. 
This  region  is  slightly  concave  both  transversely  and  longitudinally.  The  articular  surface  of 
the  quadrate  is  20  mm.  wide,  from  side  to  side,  being  relatively  greater  than  in  the  case  of  P. 
ferox.  The  squamosal  processes,  formed  by  the  backward  extension  of  the  squamosal  and  the 
paroccipital  bones,  are  large  and  scroll-like. 


TRIONYCHID^. 


531 


Neural. 

Length. 

Width. 

56 

37 

44 

3' 

38 

3' 

38 

26 

34 

21 

30 

'9 

7 

21 

H 

Seen  from  the  side  the  cutting-edge  of  the  maxilla  is  convex  from  front  to  the  hinder  end. 
The  zygomatic  arch  has  only  moderate  width.  The  tympanic  cavity  did  not  extend  so  far 
backward  into  the  squamosal  as  it  does  in  P.  ferox  and  P.  spinijera. 

Until  we  shall  have  secured  the  carapace  of  this  species  in  association  with  the  skull,  we 
must  remain  uncertain  as  to  the  genus  to  which  it  belongs. 

Amyda  egregia  sp.  nov. 
Plate  107,  figs.  1-3;    text-fig.  691. 

The  type  of  this  species  is  a  complete  carapace  which  was  collected  in  1895,  by  Mr.  O.  A. 

Peterson,  in  charge  of  the  American  Museum  expedition  of  that  year.     It  was  obtained  from 

the  lower  Washakie  beds,  south  of  Haystack  Mountain,  Wyoming.     The  number  is  1186. 

The  shell  (plate  107,  fig.  i;  text-fig.  691)  is  broad,  rounded 
in  front,  truncate  behind,  and  moderately  convex.  The  border 
is  slightly  emarginate  on  each  side  at  the  suture  between  the 
nuchal  and  the  first  costal  plate;  elsewhere  gently  repand.  The 
length  of  the  carapace,  in  a  straight  line,  is  356  mm.;  the  great- 
est width  is  334  mm. 

Of  neural  plates  there  are  seven  present.     The  table  gives 
their  dimensions.     The  first 
neural  is  only  25  mm.  wide 
at  its  hinder  end. 

The  nuchal  has  a   trans- 
verse extent  of  150  mm.  and  measures  fore  and  aft  22  mm. 

Its  outer  extremity  overlaps  the  free  end  of  the  rib  of  the 

first  costal  plate. 

The  shell  of  this  species  is  quite  thick  and  solid.   The 

thickness  of  the  fifth  costal  plate,  a  little  beyond  the  middle 

of  the  length  and  at  the  sutural  edge,  is  about  10  mm.;  in 

the  middle  of  the  width,  where  the  rib  lies,  the  thickness 

equals  15  mm. 

The  ribs  do  not  appear  to  have  projected  much  beyond 

the  margin  of  the  carapace,  apparently  only  about  30  mm. 

At  the  margin  the  shell  is  beveled  off  rather  abruptly,  but 

the  sculptured  layer  nowhere  projects  beyond  the  deeper 

layers  of  bone.     On  the  front  of  the  nuchal  the  bevel  of 

the  margin  becomes  a  broad  shallow  groove. 

The  sculpture  of  this  species  is  very  coarse.    In  the 

central  portions  of  the  carapace  (plate  107,  fig.  2)  it  consists 

of  rather  shallow  pits  separated  by  broad  low  ridges,  the 

whole  forming  a  honeycomb  structure.     The   ridges   are 

nearly  as  broad  as  the  pits.    About  three  pits,  occasionally  four,  occupy  a  line  20  mm.  long. 

The  pitting  is  coarsest  on  the  hindermost  costals,  and   here   too  the   ridges   become   more 

elevated.    On  the  outer  fourth  of  the  costals  (plate  107,  fig.  3)  the  ridges  and  pits  are  arranged 

in  rows  across  the  costals,  the  connecting  ridges  being  less  conspicuous  than  those  crossing 

the  plates.     Near  the  margin  the  irregular  honeycomb  arrangement  is  again  found.    Where 

the  pits  are  in  rows  they  are  large  and  the  ridges  conspicuous. 

This  species  somewhat  resembles  in  its  sculpture  Aspideretes  guttatus;    but  in  the  latter 

species  the  ridges  separating  the  pits  are  in  nearly  all  cases  narrower  and  sharper.     The 

sculpture  is  likewise  not  so  coarse  on  corresponding  parts  of  the  shell.     The  two  species  are 

greatly  different  in  other  characters. 

Amyda  utnta'ensis  (Leidy)  likewise  presents  a  similar  coarse  sculpture,  but  the  ridges 

intervening  between  the  pits  are  narrow  and  sharp.    Other  characters  clearly  distinguish  the 

two  species.    The  nuchal  oi  A .  utnta'ensis  has  a  considerably  greater  transverse  extension  than 

in  A.  egregta.    The  anterior  border  of  the  shell  formed  by  the  nuchal  is  more  truncated.    The 

neural  plates  differ  in  form  and  proportion,  and  there  are  only  6  of  them.    There  are  differences 

in  the  last  costals. 


Jig.  691. — Amyda  egregia.     Cara- 
pace of  type.     X  6. 


532 


FOSSIL    TURTLKS    OK    NORTH    AMERICA. 


Amyda  crassa  sp.  nov. 

Plate  io8;   text-fig.  692. 

This  species  is  founded  on  a  fragmentary  carapace,  No.  3887  of  the  American  Museum  of 
Natural  History.  This  was  collected  by  that  museum's  expedition  of  1895,  in  the  upper  beds, 
"horizon  C,"  of  the  Uinta  deposits,  in  the  region  along  White  River,  Utah.  The  parts  present 
include  a  considerable  portion  of  the  costals,  a  few  of  the  neurals,  and  nearly  the  whole  of  the 
nuchal.     Most  of  the  left  second  costal  is  missing,  about  the  distal  half  of  the  right  third, 

portions  of  both  costals  of  the  fourth  pair,  and  practically 
all  of  those  behind  the  third  of  the  right  side.  There  is  also 
at  hand  a  portion  of  a  plastral  bone  of  another  individual, 
probably  of  the  same  species;  and  this  is  labeled  "top  of 
B,  Uinta." 

In  form  the  carapace  (plate  io8;  text-fig.  692)  is  broadly 
oval,  with  the  length  exceeding  the  breadth,  and  with  the 
greatest  width  at  the  middle  of  the  length.  The  length  is 
475  mm.;  the  extreme  width,  420  mm.  The  anterior 
border  is  regularly  rounded,  while  the  hinder  border  is 
rather  truncated.  The  carapace  was  apparently  only 
moderately  convex.  There  were  8  pairs  of  costal  plates 
and  7  neurals. 

This  species  is  remarkable  for  the  thickness  of  the 
bones  of  the  carapace,  and  for  the  coarseness  of  the  sculp- 
ture, equaling  and  even  surpassing  in  these  respects  any  of 
the  species  of  the  Wasatch  deposits.  The  usual  thickness 
of  the  costals  is,  near  the  sutural  borders,  10  mm.;  thru 
the  middle  of  the  width,  13  mm.  The  thickness  of  the  outer 
end  of  the  nuchal  is  18  mm.  The  sculpture  consists  of 
ridges  and  pits,  usually  very  irregular  in  form  and  size  and 
arrangement.  The  largest  pits  may  be  8  mm.  across;  but 
there  are  commonly  2  in  about  10  mm.  The  ridges  sepa- 
rating them  may  be  as  broad  as  the  pits,  but  more  often 
they  are  narrower  and  rather  sharp.  Their  elevation  like- 
wise varies  greatly.  On  the  proximal  ends  of  the  costals  there  is  little  or  no  regularity  in  their 
disposition,  but  toward  the  distal  ends  the  pits  and  ridges  are  arranged  in  rows  running  across 
the  costals. 

The  nuchal  bone  of  this  species  resembles  that  of  A .  uinta'ensis  (Leidy),  described  and 
figured  in  this  author's  Contributions  to  the  Extinct  Vertebrata  of  the  Western  Territories, 
p.  178,  plate  xxix,  fig.  I.  Its  length  from  side  to  side  is  not  far  from  275  mm.,  while  its  fore- 
and-aft  extent  is  58  mm.  It  is  pointed  at  the  outer  ends.  There  were  no  fontanels  between  it 
and  the  first  neural  and  the  first  pair  of  costals.  There  is  a  shallow  groove,  about  10  mm. 
wide,  running  along  near  the  anterior  border;  and  this  border  is  beveled  so  that  the  upper  sur- 
face somewhat  overhangs  the  lower. 

The  free  borders  of  the  two  anterior  costals  and  of  the  more  posterior  ones  are  rounded 
off,  but  the  intermediate  ones  are  beveled.  The  first  costal  is  very  broad,  about  yj  mm.  across 
the  middle.  The  succeeding  ones  up  to  and  including  the  fifth  are  considerably  narrower, 
about  52  mm.  The  sixth  is  47  mm.  wide  at  the  proximal  end,  while  its  distal  end  is  about  80 
mm.  The  width  of  the  seventh  at  the  proximal  end  appears  to  have  been  about  36  mm., 
while  the  outer  end,  measured  along  the  oblique  free  border,  is  60  mm. 

Only  a  few  neurals  are  present,  and  none  of  these  is  complete.  Nearly  the  whole  of  the 
first  is  present.  It  is  coffin-shaped, and  the  front  end  is  convex.  The  length  was  close  to 70  mm.; 
the  width  of  the  anterior  end,  36  mm.;  that  of  the  widest  part,  near  the  hinder  end,  52  mm. 
Of  the  forms  and  dimensions  of  the  second,  third,  and  fourth  neurals,  we  can  judge -only 
from  the  spaces  which  intervene  between  their  contiguous  costals  when  these  are  in  place. 
They  were  ail  smaller  than  the  first,  but  of  the  same  general  form.  The  second,  about  whose 
dimensions  we  can  be  most  certain,  had  a  length  of  57  mm.,  and  a  width  at  the  hinder  and 
wider  end  of  43  mm.    The  fifth  neural  is  present  only  in  part.    Its  length  appears  to  have  been 


Fig.   692. — Amyda  crassa.      Cara- 
pace of  type.     X  J. 


TRIONYCHID^.  533 

44  mm.  and  its  width  close  to  30  mm.  It  was  probably  only  a  little  narrower  at  the  anterior 
end.  It  articulated  with  only  the  fifth  costal.  Most  of  the  sixth  neural  is  present.  It  was 
parallelogrammic,40mm.  longand  32  mm.  wide.  It  articulated  with  the  hinder  proximal  angle 
of  the  fifth  costal,  and  the  greater  part  of  the  proximal  end  of  the  sixth  costal.  The  seventh 
neural  is  partly  present,  and  was  probably  about  25  mm.  long  and  34  mm.  wide.  It  articulated 
with  the  sixth  and  seventh  costals  on  each  side.  It  is  not  probable  that  there  was  an  eighth 
neural.    Consequently,  the  seventh  costals  joined  in  the  midline,  as  did  also  the  eighth  costals. 

The  portion  of  the  plastral  bone  already  referred  to  is  identified  as  the  outer  end  of  the 
right  hypoplastron.  Its  catalog  number  is  3886.  It  includes  the  two  digitations  at  the  external 
angle  and  the  remainder  of  the  bone  inward  somewhat  beyond  the  narrowest  part  of  the  bridge. 
The  width,  where  narrowest,  is  32  mm.  The  length  of  the  longest  digitation  is  65  mm.  The 
thickness  at  the  free  border  equals  12  mm.;  that  thru  the  narrowest  part  of  the  bone,  23 
mm.  The  distal  free  border  is  beveled  off.  The  lower  surface  of  the  bone  is  furnisht  with  a 
sculpture  consisting  of  coarse  pits  and  ridges,  arranged,  where  well  preserved,  in  rows  parallel 
with  the  outer  border. 

Amyda  crassa  appears  to  resemble  somewhat  A.  uinta'ensts  (Leidy),  but  it  differs  in  various 
ways.  The  latter  species  has  its  greatest  breadth  somewhat  behind  the  middle  of  the  length. 
The  nuchal  bone  of  A.  crassa  is  longer,  from  side  to  side,  in  proportion  to  its  width.  The 
neurals  of  Leidy's  species  are  narrower  and  with  more  nearly  parallel  sides.  Moreover,  there 
were  only  6  neurals,  whereas,  in  A.  crassa,  there  are  7. 

Two  costal  bones,  No.  1021  of  the  American  Museum,  found  in  1895,  near  the  top  of 
division  B  of  the  Uinta  beds,  belong  apparently  to  this  species.  They  indicate  a  greater  con- 
vexity of  the  carapace  than  is  shown  by  the  type. 

Amyda?  lima  Cope. 
Plate  98,  fig.  II. 

Trionyx  lima,  CoPE,  Proc.  Acad.  Nat.  Sci.  Phila.  1869,  p.  12;  Amer.  Naturalist,  III,  1869,  p.  90;  Trans. 
Amer.  Philos.  Soc,  xiv,  1869,  pp.  151,  153,  plate  vii,  fig.  14;  Proc.  Amer.  Philos.  Soc,  xiv,  1875, 
p.  363. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  454. 

The  original  description  of  this  species  is  exceedingly  brief,  and  was  not  accompanied  by 
a  figure.  A  sufficient  description  and  figure  were,  however,  publisht  in  the  same  year.  The 
type  and  only  known  specimen,  now  in  the  American  Museum  of  Natural  History,  is  a  frag- 
ment of  the  distal  end  of  one  costal.  It  is  remarkable  for  its  heavy  construction.  The  bone 
was  somewhat  decayed  and  eroded;  and  it  is  not  certain  that  we  have  present  either  of  the 
sutural  borders.  It  is  probable,  however,  that  we  have  nearly  the  original  width  of  the  bone. 
The  present  width  is  47  mm.  The  thickness,  which  includes  the  rib,  is  18  mm.  Even  near  the 
supposed  sutural  border  the  thickness  is  14  mm.  The  rib  probably  projected  somewhat,  but 
how  much  can  not  be  determined.  At  the  free  border  the  bone  is  cut  off  at  nearly  right  angles 
with  the  upper  surface.  The  under  surface  stands  out  somewhat  farther  than  the  upper,  so 
that  there  is  a  shallow  groove  occupying  the  free  border. 

As  Cope  suggests,  the  most  conspicuous  character  of  this  species  is  found  in  its  sculpture. 
This  consists  of  rather  high  and  narrow  ridges  which  run  across  the  bone,  and  separate  grooves 
which  are  somewhat  wider  than  the  ridges  themselves.  The  summits  of  the  ridges  are  uneven 
and  are  sometimes  cut  quite  to  the  bottom.  There  are  remarkably  few  connecting  ridges; 
but  occasionally  a  ridge  is  found  to  divide;  or  it  may  suddenly  come  to  an  end.  The  distance 
across  two  grooves  is  about  7  mm.  On  the  proximal  end  of  the  fragment  the  ridges  are  some- 
what irregular  in  their  course;    at  the  distal  end  they  are  narrow  and  much   interrupted. 

In  the  American  Naturalist,  Professor  Cope  remarks  concerning  this  species: 

The  Trionyx  of  our  Miocene  {T.  lima  Cope)  was  large  and  rough,  with  narrow  ridges.  Its  remains 
occur  with  dolphins  and  porpoises,  but  it  may  have  been  floated  or  washed  from  the  mouth  of  a 
freshwater  stream  into  such  strange  company. 

There  are,  however,  reasons  for  believing  that  some  species  of  the  Trionychidae  are  not 
averse  to  living  in  salt  water. 

This  species  was  found  in  the  Miocene  marl,  in  Cumberland  County,  New  Jersey. 

With  so  little  of  the  skeleton  of  this  species  for  examination,  it  is  impossible  to  determine 
with  any  degree  of  certainty  the  genus  to  which  it  belongs. 


j|24  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

Amyda?   buiei  (Cope). 
Plate  98,  fig.  12. 

Trionyx  buiei,  CoPF,  Trains.  Amer.  Philos.  Soc,  xiv,  1869,  pp.  151,  153;  Kerr's  Report  Geol.  N.  Caro- 
lina, r,  Append.  B,  1875,  p.  34.— Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  453. 

In  the  original  description  of  this  species  Professor  Cope  stated  that  it  was  represented  by 
numerous  costal  bones  in  a  more  or  less  fragmentary  condition.  Of  these  fragments  only  a 
single  one  has  been  recognized  in  the  Cope  Collection  in  the  American  Museum  of  Natural 
History.  A  figure  of  this  is  presented  on  plate  98.  The  fragment  belongs  to  the  distal  end 
of  a  costal  plate,  and  extends  from  one  sutural  margin  to  about  the  middle  of  the  width  of  the 
plate.  The  thickness  is  slightly  less  than  5  mm.  at  the  sutural  border,  and  about  6  mm. 
thru  the  rib.     The  distal  end  of  this  plate  was  probably  about  30  mm.  wide. 

The  sculpture  consists  of  rather  low  and  narrow  ridges,  which  run  in  a  curved  course 
across  the  bone.  Some  distance  from  the  sutural  border  the  ridges  begin  to  be  connected  by 
cross-ridges,  so  that  the  intervening  furrows  become  broken  up  into  pits  of  irregular  sizes. 
Two  of  the  furrows  occupy  a  space  of  about  5  mm.  The  furrows  and  pits  are  considerably 
broader  than  the  ridges  themselves.  It  is  not  unlikely  that  the  proximal  ends  of  the  costals 
will  have  the  pitting  extended  to  the  sutural  borders. 

The  little  matrix  which  yet  adheres  to  this  bone  is  very  green. 

From  the  Miocene  near  Mount  Olive,  Duplin  County,  North  Carolina. 

Until  additional  materials  belonging  to  this  species  are  forthcoming  we  must  remain 
uncertain  as  to  its  generic  relationships. 

Amyda?  cellulosa  (Cope). 

Trionyx  cellulosus.  Cope,  Proc.  Acad.  Nat.  Sci.  Phila.  1867,  p.   142. — Hay,  Bibliog.  and  Cat.  Foss. 
Vert.  N.  A.,  1902,  p.  453. — Case,  Maryland  Geol.  Surv.,  Miocene,  1904,  p.  62. 

The  unsatisfactory  remains  on  which  the  present  species  was  founded  were  collected,  as 
stated  by  Cope  in  the  beginning  of  the  paper  cited  above,  in  Charles  County,  Maryland,  not 
far  from  the  Patuxent  River,  in  the  beds  of  the  Yorktown  epoch.  These  remains  were  never 
figured  and  appear  to  be  lost.    The  following  is  Cope's  original  and  only  description  of  them: 

Two  small  fragments  of  the  carapace  are  all  that  represent  this  species.  The  sculpture  is,  however, 
exceedingly  characteristic,  and  different  from  that  of  any  recent  or  fossil  species  known  to  the  writer. 

The  surface  is  marked  by  numerous  closely  placed  pits,  which  are  remarkably  deep,  producing  the 
vesicular  appearance  of  scoria.  The  resemblance  is  heightened  by  the  irregular  size  of  the  pits.  Edges 
of  septa  rounded.    The  fragments  are  unusually  thick,  indicating  a  species  of  large  size. 

Lines. 

Width  of  free  portion  of  rib  at  origin 7.5    [15.6  mm.] 

Depth  of  portion  of  carapace 4.33  [  9      mm.] 

The  deposits  in  which  this  species  was  found  are  now  known  as  the  Calvert  formation  of 
the  Miocene. 

In  the  same  locality  and  formation  Professor  Cope  found  other  fragments  of  a  trionychid 
which  exhibited  larger  and  more  regular  pits,  separated  by  wider  partitions  (Proc.  Phila. 
Acad.  1867,  p.  143).    To  these  he  gave  no  specific  name  and  the  specimens  appear  to  be  lost. 

Genus  TEMNOTRIONYX  nov. 

Triturating  surface  of  maxilla  with  a  sharp  ridge  running  parallel  with  the  cutting-edge 
of  the  jaw.     Presence  of  preneural  and  the  number  of  the  costals  unknown. 
Type:    Temnotnonyx  manducans  Hay. 

Temnotrionyx  manducans  sp.  nov. 

Plate  105,  figs.  2,  3;    text-fig.  690. 

In  the  Bridger  beds,  near  the  mouth  of  Cottonwood  Creek,  Wyoming,  in  1903,  the  writer 
found  some  fragmentary  remains  of  a  trionychid  which  appears  to  be  hitherto  undescribed. 
The  specimen  is  now  in  the  American  Museum  of  Natural  History,  New  York,  and  has  the 
catalog  number  5929.  The  remains  consist  of  the  left  quadrate  and  prootic,  a  portion  of  the 
right  maxilla,  the  median  portion  of  the  nuchal,  one  neural,  probably  the  fifth  or  sixth,  the 


TRIONYCHID^.  535 

sixth  costal  plate  nearly  complete,  fragments  of  several  other  costals,  nearly  the  whole  of  the 
right  hyoplastron,  the  mesial  two-thirds  of  the  right  hypoplastron,  one  cervical  vertebra,  the 
proximal  portion  of  the  right  femur,  the  distal  end  of  the  right  humerus,  and  some  other,  but 
unimportant,  fragments.     Whether  or  not  there  was  a  preneural  can  not  yet  he  determined. 

The  individual  was  a  very  large  one,  the  plastral  bones  indicating  that  the  width  of  the 
plastron  was  little  short  of  600  mm.  An  estimate,  not  wholly  reliable,  made  from  the  costals 
present,  indicates  that  the  length  of  the  carapace  was  about  500  mm.  It  is  quite  probable  that 
the  carapace  was  at  least  as  broad  as  long. 

The  skull  was  correspondingly  long.  A  comparison  of  the  united  quadrate  and  prootic 
with  those  of  Platypeltis  ferox  indicates  a  length  of  skull  of  225  mm.  from  snout  to  occipital 
condyle,  but  little  less  than  nine  inches.  The  fragment  of  maxilla  indicates  a  shorter  skull, 
about  7  inches.  It  is  not  improbable  that  the  front  of  the  skull  was  relatively  short.  The 
quadrate  and  prootic  offer  no  peculiarities  vl^hen  compared  with  those  of  Platypeltis  ferox, 
except  that  in  the  latter  the  anterior  ends  of  the  borders  which  articulate  with  the  parietal  and 
the  quadrate  respectively  rise  considerably  as  they  approach  these  bones,  thus  making  the 
anterior  end  of  the  prootic  somewhat  gutter-like;  whereas,  in  T.  manducans  the  rise  of  the 
prootic  on  each  side  is  slight  and  the  front  border  of  the  bone  is  quite  flat. 

The  fragment  of  the  maxillary  offers  the  most  interesting  modification.  Fig.  2  of  plate  105 
represents  the  bone  from  the  outside;  fig.  3  from  below.  The  lower  border  of  the  bone  forms 
a  prominent  cutting-edge,  such  as  we  find  in  many  other  trionychids.  Inside  of  this  cutting- 
edge  there  is,  in  other  trionychids,  a  horizontal  masticatory  surface  which  may  be  very  narrow 


Fig.  690. — Temnotrionyx  manducans.     Plastron  of  type.     X  i- 

or  of  moderate  width,  or  very  broad;  but  it  is  always  nearly  plane.  In  T.  manducans,  on  the 
contrary,  this  masticatory  surface  is  traverst  from  one  end  to  the  other  by  a  sharp  ridge,  such 
as  we  find  in  various  Emydidae  and  Testudinidae.  The  ridge  is  not  at  all  tootht.  Mesiad  ot  it 
the  palatal  surface  of  the  bone  past  inward  and  somewhat  upward  to  the  choanae,  and  to  meet 
the  vomer  in  front  and  the  palatine  behind.  The  structure  of  the  jaw  indicates  that  the  animal 
was  accustomed  neither  to  seizing  and  swallowing  whole  a  living  prey  nor  to  crushing  shells 
and  other  hard  objects;  but  rather  to  masticating  animal  and  vegetable  substances  of  a  mod- 
erate hardness. 

The  nuchal  bone  offers  one  peculiarity.  In  the  midline,  on  the  under  side  equally  removed 
from  the  anterior  and  the  posterior  borders,  is  an  oval  depression  14  mm.  long  and  10  mm. 
wide.  It  probably  served  as  the  attachment  of  a  ligament.  The  bone  does  not  come  to  an  edge 
in  front,  but  is  truncated.  The  thickness  is  16  mm.  The  antero-posterior  extent  of  the  bone 
was  55  mm.  The  lateral  extent  is  unknown.  There  appears  to  have  been  a^  smooth  band 
along  the  anterior  border,  narrow  at  the  midline,  while  the  remainder  is  covered  with  shallow 
pits,  4  or  5  in  a  20  mm.  line. 

Some  of  the  costals  indicate  a  considerable  convexity  of  the  carapace.  One  fragment  from 
the  middle  of  the  length  of  the  shell  has  a  width  of  65  mm.  and  a  thickness  of  10  mm.,  near  the 
sutural  border.  The  sixth  costal  is  51  mm.  wide  proximally  and  95  mm.  wide  at  the  free  border. 
Its  thickness  is  12  mm.  at  the  posterior  sutural  border.  The  upper  layer  of  the  bone  of  the 
costals  overhung  somewhat  the  middle  layer,  so  that  there  was  a  sharp  channel  running  around 
the  border  of  the  carapace.  Notwithstanding  the  age  of  the  individual  the  ribs  projected  con- 
siderably beyond  the  borders  of  the  disk,  in  one  case  42  mm. 


^^6  FOSSIL   TURTLES    OF    NORTH    AMERICA. 

The  sculpture  of  the  carapace  was  of  moderate  coarseness.  On  the  distal  halves  of  the 
costals  the  pits  are  in  rows  parallel  with  the  free  border  of  the  costal,  and  there  are  five  of  these 
rows  in  a  line  20  mm.  long.  Proximally  the  pits  are  no  longer  in  rows  and  are  larger,  3  or  4 
in  the  distance  named.    The  sutural  borders  of  the  costals  are  striated  across  the  sutures. 

Fig.  690  represents  the  known  bones  of  the  plastron.  A  portion  of  the  hyoplastron  is  miss- 
ing, but  it  is  quite  certain  that  the  outer  end  has  been  placed  very  close  to  its  proper  position. 
This  bone  had  an  extent  laterally  of  about  252  mm.,  not  including  the  antero-external  spine. 
It  is  remarkable  for  the  narrowness  of  the  end  next  the  midline,  this  being  only  60  mm.  The 
width  at  the  bridge  was  about  52  mm.  The  greatest  thickness  of  the  bone  is  about  17  mm. 
The  outer  end  of  the  hypoplastron  is  wanting,  as  well  as  the  hinder  border  of  the  bone.  The 
bottom  of  the  notch  receiving  the  inner  process  of  the  xiphiplastron  is  present,  so  that  the  form 
of  the  hypoplastron  given  in  the  drawing  is  not  far  from  correct.  The  width  at  the  narrowest 
part  of  the  bridge  is  37  mm.,  being  thus  less  than  that  of  the  hyoplastron.  The  thickness  at 
the  bridge  is  21  mm. 

On  account  of  the  advanct  age  of  the  individual,  the  layer  of  the  bone  forming  the 
"callosities"  extended  itself  to  the  ends  of  the  processes  at  the  midline.  The  lower  surface  of  the 
plastral  bones  is  nearly  smooth,  but  shows  everywhere  the  vestiges  of  pits  and  ridges.  Where 
distinct  enough  to  be  perceived  they  seem  to  have  been  smaller  than  those  ot  the  carapace. 

The  sculpture  of  the  carapace  of  this  species  resembles  that  o{  Amyda  uintaensts,  consisting 
of  large  pits  at  the  proximal  end  of  each  costal  and  somewhat  smaller  ones  in  rows  at  the  distal 
end.  Those  of  T.  manducans  are,  however,  somewhat  larger,  in  corresponding  situations. 
The  shell,  too,  is  thicker.  The  greatest  differences  are  found  in  the  plastra  of  the  two  species. 
In  A.  uintaensis  the  inner  end  of  the  hyoplastron  is  two  and  a  half  times  as  wide  as  the  nar- 
rowest portion  at  the  bridge;  whereas,  in  T.  manducans  the  two  portions  are  of  nearly  the 
same  width.  The  front  border  oi  A .  uintaensis  was  quite  concave,  while  that  of  T.  manducans 
was  nearly  straight.  It  is  not  probable  that  such  differences  can  be  due  to  difference  in  age. 
The  type  oi  A.  uintaensis  is  about  four-fifths  as  large  as  that  of  the  present  species. 

From  Amyda  scutumantiquum  the  present  species  differs  in  the  same  way  that  it  does 
from  A .  uintaensis;  that  is,  in  the  narrowness  of  the  inner  end  of  the  hyoplastron.  A.radula, 
whose  nuchal  has  a  similar  thickened  anterior  border,  differs  in  having  a  thinner  shell,  the 
free  borders  of  which  are  beveled,  and  in  having  a  finer  sculpture.  A.  egregia  has  a  thicker 
shell,  a  coarser  sculpture,  and  no  overhanging  layer  at  the  free  borders.  A.?  cariosa,  of  the 
Wasatch  of  New  Mexico,  evidently  had  much  deeper  and  more  abrupt  pits  on  the  proximal 
ends  of  the  costals.  The  bone  regarded  by  Cope  as  a  xiphiplastral  was  deeply  pitted,  a  con- 
dition not  to  be  expected  in  T .  manducans.  Aspideretes  guttatus  has  a  different  sculpture 
and  a  relatively  broader  bridge.  Aspideretes  ellipticus  had  a  nuchal  whose  anterior  border 
was  beveled  off  on  the  upper  surface. 

Genus  PLATYPELTIS  Fitzinger. 

Carapace  with  the  eighth  pair  of  costals  wanting  or  greatly  reduced.  No  preneural.  One 
or  two  of  the  posterior  pairs  of  costals  may  be  in  contact  on  the  midline,  or  all  may  be  separated. 
Young  in  the  living  species  with  smooth  or  granulate  skin. 

The  type  of  the  genus  Platypeltis  is  Testudo  ferox  Schneider  (=Trtonyx  ferox  of  Boulen- 
ger's  Catalogue).    The  known  living  species  are  all  inhabitants  of  North  America. 

Key  to  Fossil  Species  of  Platypeltis. 

A^.  Puerco    or   Torre jon    species: 

I.  Nuchal  probably  loosely  attacht  to  first  costals.    No  welts  on  carapace.    Six  pits 

in   a  line   10  mm.  long antiqua 

A^.  Wasatch  species: 

1.  Disk  of  carapace  not  as  wide  as   long;    with    ribs   projecting   far   beyond   disk. 

Nuchal  probably  loosely  connected  with  its  costals  and  neural;  sculpture  coarse, 

with  welts serialis 

2.  Sculpture  coarse,   especially  on  proximal  ends  of  the  costals,  but  without  welts. 

Anterior  border  of  hyoplastron  concave amnicola 

A^.  Bridger  species: 

1 .  See  A^,   I serialis 

2.  Nuchal  sutured  to  first  costals;   welts  not  conspicuous;   5  to  7  pits  in  10  mm.  .  .  .  trepida 


TRIONYCHID^.  537 

3.  Carapace  oval,  not  so  wide  as  long,  archt;   nuchal  about  half  the  width  of  cara- 

pace; pits  of  costals  small  and  shallow;  hinder  end  of  carapace  with  longitudinal 

welts trtonychoides 

4.  Carapace  as  broad  as  long;    nuchal  hardly  half  the  width   of  the  carapace;    a 

smooth  band  along  its  front;    sculpture  coarse  near  midline heteroglypta 

5.  Carapace  broader  than  long;    nuchal   more   than   half  the   width   of  carapace; 

pitted  to  free  border;    sculpture  as  in   preceding postera 

6.  Carapace   broader   than    long;     nuchal    not    half  the   width    of  the    carapace; 

sculpture  like  that  of  heteroglypta externa 

A*.  Oligocene  species: 

I.  Carapace  thin,   broader  than   long;    nuchal  0.6  the  width  of  the  carapace;    a 

fontanel  each  side  of  first  neural leucopotomica 

A'.   Pliocene  and  recent  species: 

I.  Carapace  elliptical;   longer  than  wide;   nuchal  about  half  the  width  of  the  cara- 
pace;  sculpture   rather  coarse jerox 


Platypeltis  antiqua  Hay. 
Fig.  693. 

Platypeltis  antiqua,  Hay,   Bull.  Amer.  Mus.  Nat. 
Hist.,  XXIII,  1907,  p.  859,  fig.  18. 

The  specimen  which  represents  this  species 
appears  to  have  been  collected  for  Professor 
Cope  by  Mr.   D.   Baldwin,  in    1883,  in  the 
Torrejon  beds  of  northern  Mexico.     It  pre- 
sents wholes  or  parts  of  5  pairs  of  costals  and 
5  neural  bones.  Some  other  bones  are  buried 
in  the  very  refractory  matrix.     The  catalog 
number  is  1036. 
The    carapace 
(fig.  693)   had   a 
length   of    about 
100   mm.   and   a 
width  of  78  mm.; 
but   the  ends   of 

the  ribs  extended  beyond  the  disk  at  least  18 
mm.  What  is  evidently  the  first  costal  is  20 
mm.  long,  from  neural  to  distal  end,  and  13 
mm.  fore  and  aft.  Its  anterior  border  is  smooth,  showing  that  it  was  not  suturally  joined  to 
the  nuchal.  The  table  shows  the  dimensions  of  the  neurals  present.  They  are  from  2.5  mm. 
to  3  mm.  thick. 

The  surface  of  the  costals  presents  no  welts,  but  is  everywhere  pitted.    On  the  proximal 
ends  of  the  costals  there  are  6  pits  in  a  10  mm.  line;  on  the  outer  ends,  5  pits. 


Neural. 

Length. 

Width. 

z 

3 
4 

5 

H 
16 

'5 
12 

10 

9 
8 
6 

Fig.  693. 


-Platypeltis  antiqua.     Carapace 
of  type.     X  f. 


Platypeltis  serialis  (Cope). 
Plate  98,  fig.  13;    plate  109,  figs.  1-4;   text-figs  694-696. 

Trionyx,  Leidy,  Contrib.  Ext.  Vert.  Fauna  West.  Terrs.,  1873,  p.  180,  plate  xvi,  fig.   11. 

Plasttimenus  ?thomasii.  Cope,  Syst.  Cat.  Vert.  Eocene,  New  Mexico,  1875,  p.   ^5. 

Plastomenus  thomasii.  Cope,  Wheeler's  Surv.  W.  looth  Merid.,  iv,  1877,  P-  49-   (Not  Trionyx  thomasii 

Cope,  1872.) 
Plastomenus  thomasi.  Cope,  Vert.  Tert.  Form.  West,  1884,  p.  125.     (Not  Trionyx  thomasii  Cope,  1872.) 
Plastomenus  serialis,  Cope,  Wheeler's  Surv.  W.  lOOth  Merid.,  iv,  1877,  pp.  48,  51,  pi.  xxv,  figs.  8-10; 

Vert.  Tert.  Yoxm.  West.,  1884,  p.  123. — Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1903,  p.  453. 
Platypeltis  serialis.  Hay,  Amer.  Geologist,  xxxv,  1985,  p.  337. 

The  types  of  the  present  species  appear  to  have  been  lost.  We  must,  therefore,  depend 
for  the  identification  of  the  species  on  the  author's  description  and  illustrations.  Professor 
Cope  possest  fragmentary  remains  of  five  individuals,  which  he  had  obtained  from  the  Wasatch 


538  FOSSIL   TURTLES   OF    NORTH    AMERICA.  ' 

deposits  of  New  Mexico.  His  figures  represent  fragments  of  3  costal  plates.  He  states  that 
the  species  is  readily  distinguisht  by  the  closely  placed  subparallel  ridges  which  cross  the  ribs 
parallel  to  the  axis  of  the  body  and  which  are  separated  by  one  or  two  rows  of  imprest  dots, 
or  small  fossae. 

The  costals  varied  in  width  from  18  mm.  to  27  mm.  and  in  thickness  from  3  mm.  to  5 
mm.     Three  and  a  half  ridges  occupied  a  space  of  9  mm. 

The  American  Museum  of  Natural  History  expedition  of  1903  to  the  Bridger  beds  in  the 
region  about  Fort  Bridger,  Wyoming,  secured  a  large  portion  of  the  carapace  and  a  consider- 
able part  of  the  plastron  of  a  specimen  which  it  appears  necessary  to  refer  to  Cope's  Wasatch 
species.  When,  however,  more  satisfactory  materials  of  the  latter  have  been  secured,  it  may 
prove  that  the  Bridger  remains  belong  to  an  unnamed  species. 

Cope's  assignment  of  his  materials  to  the  genus  Plastomenus  depended  on  no  part  of  the 
plastron,  and  was  therefore  inconclusive.  There  is  reason  to  believe  that  the  Bridger  speci- 
men does  not  belong  to  Plastomenus,  but  must  be  assigned  to  Platypeltis.  It  bears  the  cata- 
log number  6014. 

Of  the  individual  here  described  (plate  98,  fig.  13)  there  are  present  most  of  the  first 
neural  and  the  whole  of  the  third;  practically  all  of  the  6  anterior  costal  plates,  and  a  fragment 
of  the  seventh;  the  mesial  half  of  the  right  hyoplastron  and  hypoplastron;  and  somewhat  more 
of  the  mesial  half  of  the  same  bones  of  the  left  side. 

It  is  evident  that  the  nuchal  of  this  individual  had  no  sutural  connection  with  the  costals 
of  the  anterior  pair;  whether  or  not  it  had  such  connection  with  the  first  neural  is  made  doubt- 
ful by  the  fact  that  the  anterior  portion  of  this  bone  is  missing.  The  hinder  border  of  the 
carapace  being  gone,  as  well  as  the  nuchal,  the  length  can  not  be  determined.  From  the  front 
of  the  first  costal  to  the  hinder  border  of  the  sixth  is  95  mm.  Judging  from  the  curve  of  the  free 
borders  of  the  sixth  costals,  but  a  few  millimeters,  perhaps  lO  mm.,  would  have  been  added 
by  the  seventh  costals.  If  now  we  add  10  mm.  as  the  width  of  the  nuchal,  we  shall  have  as 
the  probable  length  of  the  carapace  105  mm.  The  width  of  the  disk  is  100  mm.  How  far  the 
ribs  projected  beyond  the  disk  can  not  be  determined. 

The  first  neural  had  a  length  of  about  16  mm.  and  a  width  of  13  mm.  The  third  has  the 
same  length,  but  is  12  mm.  wide.  Both  are  of  hexagonal  form,  with  the  narrow  end  directed 
forward.  The  sixth  neural  was  also  of  the  same  form,  but  had  the  narrow  end  directed  back- 
ward. There  was  present  a  small  seventh  neural  wedged  in  between  the  costals  of  the  sixth 
and  seventh  pairs. 

The  third  costals  are  17  mm.  wide  near  their  outer  ends,  3.5  mm.  thick  near  the  sutural 
borders,  and  5  mm.  thru  the  rib.  Toward  the  outer  ends  of  the  costals  the  ribs  become  quite 
prominent  on  the  inner  surfaces  of  the  former. 

The  ornamentation  of  the  carapace  agrees  with  that  of  Cope's  Plastomenus  serialis. 
There  are  on  each  side  about  7  longitudinal  ridges,  or  welts.  These  are  low  on  the  front  of  the 
shell  but  much  more  prominent  posteriorly.  Five  of  these  ridges  cross  the  sixth  costal.  Be- 
tween the  ridges  there  are  from  I  to  3  rows  of  pits  of  varying  sizes.  On  the  neurals  there  are 
only  small  pits,  or  punctae. 

The  plastron  of  this  specimen,  so  far  as  represented,  was  like  that  of  Platypeltts  spinijera. 
The  width  of  the  hyoplastron  (plate  109,  fig.  3),  where  narrowest,  is  7  mm.;  that  of  the  hypo- 
plastron at  the  same  place,  is  10  mm.  The  inner  end  of  the  former  bone  expanded  into  a 
single  flat  process;  that  of  the  hypoplastron  into  two  such  processes.  A  callosity  of  15  mm. 
width  occupied  these  bones  along  their  common  suture,  about  half  of  it  on  each  bone. 

No.  5944  of  the  American  Museum  of  Natural  History,  a  specimen  collected  at  Grizzly 
Buttes,  Wyoming,  in  1903,  is  referred  to  this  species.  It  consists  of  portions  of  the  carapace, 
the  right  hyoplastron  and  hypoplastron  nearly  complete,  the  median  halves  of  the  same  bones 
of  the  left  side,  portions  of  the  pectoral  and  pelvic  girdles,  and  parts  of  the  humerus  and  femur. 
These  belonged  to  an  older  and  larger  individual  than  the  one  just  described.  The  carapace 
(plate  109,  fig.  4)  is  remarkable  for  the  strong  development  of  the  longitudinal  ridges;  but  it 
is  not  believed  that  a  distinct  species  is  indicated.  One  fragment  belongs  to  the  hinder  rim 
of  the  carapace,  and  presents  the  seventh  and  eighth  costals  of  the  right  side.  The  eighth 
costal  was  small.    The  plastron  (plate  109,  fig.  2;  text-fig.  694)  is  in  a  more  advanct  stage  of 


trionychiDj?:. 


539 


growth  than  that  of  the  specimen  numbered  6014.  The  so-called  callosities  are  much  more 
extensive,  a  feature  of  age.  They  have  a  width  of  about  40  mm.  The  length  of  the  hyo- 
hypoplastral  suture  is  74  mm.;  the  width  of  the  bridge  is  27  mm.;  the  thickness  at  the  bridge, 
7  mm.  A  comparison  of  the  femur  (fig.  695)  with  corresponding  parts  of  P.  spinifera  appears 
to  show  that  the  shaft  was  nowhere  so  slender  as  in  the  living  species,  while  the  distal  end  was 
not  so  broad.  The  parts  of  the  pelvis  present  display  no  important  differences  when  compared 
with  the  pelvis  of  P.  spinifera. 

Mr.  Paul  Miller,  of  the  American  Museum  of  Natural  History  expedition  of  1904,  collected 
a  nearly  complete  carapace  (No.  3947)  of  a  trionychid  which  the  writer  refers  to  this  species. 
It  is  shown  on  plate  109,  fig.  i ;  text-fig.  696.  This  came  from  the  lower  portion  of  the  beds 
designated  as  C,  and  is  therefore  of  later  date  than  the  Grizzly  Buttes  specimens.  The  striking 
feature  in  the  carapace  is  the  feeble  development  of  the  longitudinal  ridges,  or  welts,  the 
specimen  presenting  thus  a  great  contrast  to  No.  5944.  The  ridges  are  moderately  distinct 
on  the  last  three  pairs  of  costal  plates,  but  farther  foi-ward  they  rapidly  become  obsolete. 
The  pits  are  of  the  same  size  as  in  the  other  specimens  and  are  separated  by  rounded  walls. 


Figs.  694-696. — Platypehis  serialis. 


694.  Plastron.    Xi- 

695.  Femur.    Xi. 

696.  Carapace.    X^. 


696. 


The  nuchal  of  this  specimen  also  is  missing.  It  must  have  been  very  loosely  attacht, 
just  as  it  is  in  P.  spinifera,  even  the  first  neural  having  its  anterior  border  smooth.  The  left 
eighth  costal  is  missing.  The  length  of  the  specimen,  as  known,  is  131  mm.;  with  the  nuchal 
it  was  probably  about  150  mm.  The  width  of  the  disk,  exclusive  of  the  rib  ends,  is  105  mm.; 
but  including  these,  it  was  about  175  mm.  It  must  therefore  have  been  a  more  elongated 
animal  than  P.  spinifera.  The  great  extension  of  the  rib-ends  beyond  the  disk  shows  that  it 
was  only  of  medium  age. 

The  disk  is  rather  flat,  and  was  probably  so  during  life.  There  are  six  neurals.  The  fifth 
comes  into  contact  with  only  its  own  costals.  The  sixth  is  triangular  and  reduced  in  size. 
The  costals  of  the  eighth  pair  are  small  and  hardly  come  into  contact  at  the  midline. 

In  the  Vertebrata  of  the  Tertiary  Formations  of  the  West,  1884,  p.  126,  Professor  Cope, 
in  discussing  the  genus  Plastomenus,  writes  as  follows:  "The  true  P.  thomasii  was  founded 
on  sternal  bone[s]  perhaps  of  a  small  species  of  Triotiyx."     Since  in  the  earliest  description  of 


540 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


this  species  no  plastral  bones  are  mentioned,  and  in  subsequent  and  more  detailed  descriptions 
the  plastral  bones  mentioned  are  not  Trionyx-like,  we  must  regard  the  name  P.  thomasti  as 
belonging  to  those  specimens  which  were  afterward  called  P.  multifoveatus.  In  the  Cope 
collection  of  reptiles  in  the  American  Museum  of  Natural  History  there  are  present  the  median 
ends  of  the  right  and  left  hyoplastra  and  a  fragment  of  the  left  hypoplastron  of  a  trionychid 
which  are  accompanied  by  Cope's  labels,  which  read  as  follows:  " Plastomenus  thomasii, 
hyosternals"  and  "Plastomenus  thomasii,  sternum  like  Trionyx."  The  bones  bear  the  number 
1022,  of  the  American  Museum.  It  seems  quite  certain  that  these  specimens  are  the  alleged 
types  of  P.  thomasti;  but  it  is  quite  as  certain  that  they  have  never  been  described.  A  com- 
parison of  them  with  the  plastral  bones  of  Bridger  specimens  of  Platypeltis  serialis  proves 
that  all  belong  to  the  same  species,  the  resemblances  between  the  hyoplastra  of  No.  I022  and 
No.  5944  being  very  close. 


Platypeltis  amnicola  Hay. 

Fig.  697. 


Platypeltis   nmnicoln.   Hay,    Bull.   Amer. 
text-fig.  19. 


Ml 


Nat.    Hist.    XXIII,   1907,  p.   860,   pi.   liv,   figs.   5,  6; 


r-v 
■f^ 

VJ 


The  incomplete  and  fragmentary  remains  which  stand  as  the  type  of  the  present  species 
were  secured  by  the  American  Museum  expedition  of  1906  into  the  Wasatch  beds  of  south- 
western Wyoming.     The  specimen  was  found  on  Bitter  Creek.     There  are  present  2  neural 

bones,  apparently  enough 
Fig.  6gj.— Platypeltis  amnicola.    Left  fragments  to  restore  near- 

hyoplastron  and  hypoplastron  \y  ^\\  ^hg  costals,  most  of 

ot  type.     X^.  ,5j*^     the  hyoplastron  and  hypo- 

plastron of  the  left  side 
and  the  inner  ends  of 
those  of  the  right  side. 
The  catalog  number  is 
6044. 

The  carapace  had  a 
length  of  about  280  mm. 
and  a  width  of  200  mm. 
or  more.  The  species  ap- 
pears to  have  resembled 
Platypeltis  heteroglypta  of 
the   Bridger   beds. 

What  is  regarded  as  the 
'.,/     ,'  /  third   neural  is   35    mm. 

long,  25  mm.  wide,  and 
6  mm.  thick.  One  costal  bone  is  46  mm.  wide  at  the  distal  end,  while  the  sixth  of  the  left 
side  is  36  mm.  wide  distally.  The  eighth  costal  of  the  right  side  is  present.  It  is  small,  and 
was  evidently  inclosed  in  a  notch  in  the  seventh  costal.  The  free  ends  of  all  the  costals  are 
beveled  off  obliquely. 

There  appear  to  be  no  welts  on  the  costals.  The  pits  vary  considerably  in  size.  Near  the 
distal  ends  the  pits  are  arranged  somewhat  in  rows  parallel  with  the  free  border,  and  there  are 
usually  6,  sometimes  7,  in  a  line  20  mm.  long.  Toward  the  proximal  ends  the  pits  increase  in 
size  so  as  to  be  two  or  three  times  as  large  as  those  of  the  distal  ends.  They  are  arranged 
more  irregularly  also. 

The  length  of  the  suture  between  the  hyoplastron  and  the  hypoplastron  (fig.  697)  seems 
to  have  been  close  to  120  mm.  The  bridge  is  45  mm.  wide,  and  here  the  bones  are  13  mm. 
thick.  The  lower  surface  of  the  bones,  except  the  processes,  is  ornamented  with  ridges  and 
pits.    Of  the  pits  there  are  usually  5  in  a  line  10  mm.  long. 

We  may  suppose  that  the  plastron  of  P.  heteroglypta  resembled  that  of  P.  postera.  That 
of  P.  amnicola  differs  much  from  that  of  P.  postera,  especially  in  having  the  anterior  border 
of  the  hyoplastron  concave,  instead  of  nearly  straight. 


TRIONYCHID^.  54I 

Platypeltis  trepida  Hay. 
Fig.  698. 
Plutypeltis  Ircpida,  May,  Bull.  Amer.  Mus.  Nat.  Hist,  xxill,  1907,  pi.  liv,  fig.  7;   text-fig.  20. 

The  single  known  specimen  of  this  species  was  found  by  the  American  Museum  expedition 

of  1906  into  the  Bridger  beds  of  southwestern  Wyoming.    It  was  secured  at  Grizzly  Buttes  in 

the  level  designated  as  B.    The  catalog  number  is  5925. 

The  nuchal  bone  is  wanting,  as  well  as  most  of  the  costals  of  the  right  side  and  all  the 

,-- ■.,  neurals  except  the  fourth   and  the  fifth. 

■    5.=>~_  ^j,-f'    \  The  original  length  of  the  specimen  was 

close  to  100  mm.    The  distance  from  the 

anterior  border  of  the  first  costal  to  the 

hinder  border  of  the  fifth  at  its  distal  end 

is  YJ  mm.    The  breadth  of  the  disk  is  92 

mm.     Beyond  this  the  ribs  extended   at 

least  15  mm. 

;■  The  fourth  neural  is  11  mm.  long  and 

9  mm.  wide.  The  fifth  is  10  mm.  long  and 

1---^      8  mm.  wide.     Each  of  these  bones  bears 

/- '     a  low  median  keel. 

The  costals  are  thin,  the  thickness  being 

about  2  mm.   The  first  is  i6  mm.  wide;  the 

""---•'       second  is  12  mm.  wide  at  the  distal  end. 

;_._A         /'  V'  ~^  /' "^^  The  anterior  border  of  the  first  shows  that 

^-/  ;  ^■•,   /'^~"— '  it  was  articulated  by  a  jagged  suture  with 

''-^-^-^ /'--■'--V  -<^'  ^^^  nuchal  bone.    The  costals  show  some 

„       ,  „      n,         ,.  ■ ,      Z^  '     r  ,,9      faint  traces  of  longitudinal  welts.    The  pits 

riG.  000. — Flatypelus  treptda.  Carapace  of  type.  X  1-  ,  ,  •  n  1      •  1 

'  ,  /rj      3j.g  mostly  arranged  \n  rows  parallel  with 

these  more  prominent  ridges.    There  are  from  5  to  7  pits  in  a  line  10  mm.  long. 

The  closer  connection  of  the  nuchal  with  the  first  costals,  the  finer  sculpture,  and  the  keel 

on  the  neurals  distinguish  this  species  from  P.  serialis. 

Platypeltis  trionychoides  (Cope). 
Plate  no,  figs.  1-2;   text-figs.  699,  700. 

Anostira  trionychoides,  CoPE,  Proc.  Amer.   Philos.  Soc,  xii,   1872,  p.  461. 

Plastomenus  trionychoides.  Cope,  Proc.  Acad.  Nat.  Sci.  Phila.  187^,  p.  279;   Ann.  Report  U.  S.  Geol. 

Surv.  Wyoming,  etc.,  1872  (1873),  p.  619;  Vert.  Tert.  Form.  West,  1884,  p.  I2j,  plate  xviii,  fig.  I. — 

Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  453. 
Platypeltis  trionychoides.   Hay,  Amer.  Geologist,  xxxv,   1905,  p.  336. 

Professor  Cope  originally  referred  the  present  species  to  the  genus  Anostcira,  a  proceeding 
due,  as  he  tells  us,  to  the  fact  that  the  type  specimens  were  found  commingled  with  various 
bones  of  A nosteira  ornata  and  all  were  supposed  to  belong  to  one  species.  When  the  error  was 
discovered,  the  trionychoid  bones  were  assigned  to  Plastomenus.  The  character  of  the  sculp- 
ture doubtless  determined  this  distribution  of  the  species,  for  it  does  not  appear  that  Cope 
possest  any  of  the  plastron.  Cope's  figured  specimens  of  his  species  are  now  in  the  U.  S. 
National  Museum,  but  fragments  of  costal  bones,  bearing  Cope's  label  stating  that  they  are 
type  specimens,  are  in  the  American  Museum  of  Natural  History.  They  are  in  all  probability 
portions  of  the  type  which  have  become  separated  from  the  figured  specimens.  All  of  Cope's 
specimens  of  the  species  came  from  Cottonwood  Creek,  Wyoming,  and  hence  from  the  level 
known  as  B. 

Figs.  I  and  2  of  plate  1 10  are  reproduced  from  photographs  of  a  nearly  complete  specimen 
of  the  species  which  was  obtained  by  the  American  Museum  expedition  of  1903  into  the  Bad- 
lands of  southwestern  Wyoming.  This  specimen,  which  furnishes,  besides  the  carapace,  a 
large  part  of  the  plastron,  both  humeri,  and  both  femora,  was  found  at  Grizzly  Buttes.  The 
number  of  the  specimen  in  the  American  Museum  is  5938.    The  length  of  the  carapace  along 


542 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


the  midline  is  132  mm.;  the  extreme  width  is  117  mm.  The  carapace  (fig.  699)  is  moderately 
convex.  The  anterior  border  is  broadly  rounded;  the  hinder  border  is  excavated.  There 
were  originally  6  neural  bones,  of  which  the  first  is  injured  and  the  fourth  is  missing.  The  first 
had  a  length  of  21  mm.  and  a  width  of  10  mm.  The  others  are  shorter  and  narrower.  The 
nuchal  has  a  fore-and-aft  extent  of  18  mm.  and  a  length  of  66  mm.  from  side  to  side.  There 
are  only  7  pairs  of  costals.  Those  of  the  seventh  pair  meet  at  the  midline.  The  costals  are 
about  3  mm.  in  thickness.  The  sculpture  of  the  specimen  agrees  with  that  of  the  type,  but  it 
is  more  feebly  developt.  The  surfaces  of  the  neurals  and  the  proximal  ends  of  the  costals 
present  shallow  pits  arranged  irregularly.  Of  these  pits  there  are  from  5  to  7  in  a  line  10  mm. 
long.  Toward  the  distal  ends  of  the  costals  the  pits  become  smaller  and  more  closely  packt, 
there  being  about  10  in  a  10  mm.  line. 

The  greater  portions  of  both  hyoplastra  and  both  hypoplastra  accompany  the  carapace. 
There  was  a  considerable  fontanel  between  the  hypoplastrals  in  front  and  the  xiphiplastrals 
behind.  The  mesial  half  of  the  hyoplastra  and  of  the  hypoplastra  are  only  3  mm.  thick;  but 
the  thickness  is  somewhat  greater  near  the  distal  ends  of  the  bones.  The  bridges  are  26  mm. 
wide.  The  length  of  the  hyohypoplastral  suture  is  61  mm.  The  sculpture  of  these  bones  is 
greatly  like  that  of  the  carapace. 


700. 


Figs.  699  and  700. — Plutypellis  trtonychoides.     Xi- 
699.  Carapace  of  No.  5938  A.  M.  N.  H.  700.  Plastron  restored  from  No.  5938  and  No.  6017  A.  M.  N.  H. 

The  limb  bones  present  show  no  important  differences  when  compared  with  those  of  P. 
spinijera. 

No.  6017,  of  the  American  Museum  of  Natural  History,  was  found  at  Grizzly  Buttes  in 
1903.  It  furnishes  fragments  of  the  costals,  some  neurals,  and  nearly  the  whole  of  the  plastron 
except  the  entoplastron  and  the  epiplastra,  elements  of  the  plastron  rarely  recovered,  on 
account  of  their  loose  attachment  and  their  delicate  construction.  This  specimen  differs  from 
the  preceding  only  in  the  boldness  of  the  sculpture,  the  pits  being  deeper  and  the  ridges  higher 
and  sharper.  It  is  coarsest  on  the  outer  ends  of  the  hyoplastrals  and  the  hypoplastrals.  From 
this  specimen  has  been  drawn  most  of  the  plastron  as  represented  in  fig.  700,  but  parts  of 
this  figure  have  been  taken  from  the  plastron  of  No.  5938. 

No.  5942,  American  Museum,  also  from  Grizzly  Buttes,  belonged  to  a  larger  and  an  older 
individual  than  the  specimeqs  already  described.  The  hyoplastron  is  co-ossified  with  the 
hypoplastron.  Following  the  line  of  the  missing  suture,  the  distance  is  92  mm.  The  bones 
are  a  little  over  4  mm.  thick  on  the  mesial  half;  at  the  bridge  they  are  about  8  mm.  thick. 
The  sculpture  is  strongly  exprest,  especially  on  the  bridges. 

The  xiphiplastron  differs  in  having  the  outer  border,  near  the  base  of  the  process  entering 
the  hypoplastron,  expanded  outward.  This  is  due  probably  to  the  greater  age  of  the  animal. 
The  bone  is  5  mm.  thick;  that  of  No.  6017  is  4  mm. 


TRIONYCHID^.  543 

Platypeltis  heteroglypta  (Cope). 
Plate  98,  fig.  14;    plate  loi,  fig.  2;   text-figs.  701,  702. 

Trionyx  heteroglyptus,  CoPE,  Proc.  Acad.  Nat.   Sci.   Phila.    1873,   p.   277;  U.   S.  Geol.  Surv.  Terrs., 

6th  Ann.  Report,  1872,  (1873),  p.  616;  Vert.  Tert.  Form.  West,  1884,  p.  120,  plate  xvi,  fig.  2. — 
Hay,  Bibliog.  and  Cat.  Foss.  Vert.  N.  A.,  1902,  p.  454. 

Platypeltis  heteroglyptus,  Hay,  Amer.  Geologist,  xxxv,  1905,  p.  336. 

The  type  of  this  species  is  the  hinder  half  of  a  carapace  and  the  complete  nuchal  bone, 
which  were  collected  in  1872,  by  Professor  Cope,  on  the  summit  of  Church  Butte,  Uinta 
County,  Wyoming.,  This  specimen  is  now  in  the  American  Museum  of  Natural  History, 
New  York,  and  bears  the  number  1039.  Cope  figured  it,  as  above  cited,  and  attempted  to 
restore  in  outline  the  missing  parts;  but,  as  stated  in  the  explanation  of  the  plate,  too  few 
costals  are  represented.  As  there  restored,  the  carapace  is  considerably  broader  than  long, 
which  almost  certainly  was  not  the  case.  Certainly  2,  and  possibly  3,  costals  come  in  front  of 
the  most  anterior  costal  present,  the  fifth  one  from  the  rear.  In  the  diagram  here  presented 
(fig.  701),  the  carapace  is  restored  with  7  costals,  the  number  present  in  the  living  American 
species  of  the  family.  There  is  a  neural  plate  between  the  hindermost  costals.  These  costals 
may  be  those  of  the  eighth  pair  and  the  neural  therefore  the  eighth;  but  an  eighth  neural  is 
so  seldom  developt  [Amyda  (equa)  that  it  is  more  probable  that  this  is  the  seventh  neural  and 
the  costals  those  of  the  seventh  pair.  For  this  reason  the  species  is  referred  to  the  American 
living  genus  Platypeltis. 

Cope  has  represented  the  distal  end  of  the  fifth  costal  from  the  rear  as  being  drawn  in 
farther  than  the  specimen  justifies.  In  fact,  its  free  margin  stood  out  nearly  as  far  as  did  that 
of  the  next  one  behind. 

Professor  Cope  did  not  know  of  the  nuchal,  it  having  been  found,  since  the  specimen  came 
into  the  American  Museum,  lying  in  the  matrix  beneath  the  hinder  end  of  the  carapace.  Its 
antero-posterior  breadth,  in  the  midline,  is  26  mm.;  its  length,  from  side  to  side,  about  120  mm. 
It  is  therefore  rather  small  for  a  turtle  of  the  size.  This  nuchal  articulated  with  the  first  neural 
and  probably  with  the  anterior  costals  without  fontanels.  The  upper  surface  is  sculptured  on 
the  anterior  edge  for  26  mm.  on  each  side  of  the  midline.  Beyond  this,  the  surface  is  devoid 
of  ornamentation.  At  the  ends  of  the  sculptured  area  the  thickness  is  10  mm.  The  outer  ends 
of  the  nuchal  were  partially  overlapt  by  the  outer  ends  of  the  first  pair  of  costal  plates. 

The  carapace  was  possibly  quite  flat,  but  more  probably  it  had  considerable  convexity. 
There  is  a  narrow,  but  rather  deep  notch  in  the  hinder  margin  of  the  carapace,  at  the  midline. 
The  measurements  given  in  Cope's  description  are  correct.  The  greatest  width  is  250  mm., 
taken  between  the  distal  ends  of  the  fourth  pair  of  costals  from  the  rear.  The  distance  from 
the  rear  of  the  shell  to  the  anterior  border  of  the  most  anterior  costal  present  is  162  mm.  The 
total  length  of  the  shell  may  be  estimated  at  from  250  mm.  to  280  mm.  The  thickness  of  a 
costal  plate  near  its  sutural  border  is  6  mm.  The  ribs  stand  out  conspicuously  on  the  under 
side  of  the  plates,  and  thru  them  the  thickness  amounts  to  10  mm.  Cope  states  that  the  free 
portion  of  the  costal  is  short.  This  probably  refers  to  the  projection  of  the  rib  beyond  the 
plates.  The  rib  of  the  penultimate  costal  is  present  and  projects  at  least  33  mm.  The  hinder- 
most  pair  of  costals  join  along  the  midline  for  25  mm.  The  neural  which  is  lodged  between  the 
front  borders  of  the  hindermost  costals  is  14  mm.  long  and  just  as  wide.  The  next  neural 
in  front  seems  to  have  been  24  mm.  long  and  about  14  mm.  wide.  Its  broader  end  is 
directed  forward,  and  its  anterior  angles  come  into  contact  with  the  antepenultimate  costals. 
A  portion  of  the  antepenultimate  neural  is  present  and  appears  to  have  had  about  the  same 
width  as  the  ones  behind  it.  Its  length  was  about  25  mm.,  and  it  has  lain  wholly  between  the 
costals  of  the  antepenultimate  pair,  coming  into  contact  with  neither  the  pair  in  front  nor  that 
behind.  Its  hinder  end  has  been  slightly  broader  than  the  front  end.  Only  a  fragment  of  the 
neural  next  in  front  of  the  one  just  described  is  present.  Its  broader  end  has  been  directed 
backward  and  this  has  come  into  contact  with  the  antepenultimate  costals.  The  first  neural 
has  had  a  convex  anterior  border  to  fit  the  concave  border  of  the  nuchal. 

The  sculpture  of  the  different  parts  of  the  shell  varies  greatly.  On  the  proximal  ends  of 
the  hindermost  costals  it  is  coarse  and  consists  of  longitudinal  ridges,  with  some  lateral  spurs. 
In  the  middle  of  the  length  of  the  other  costals  there  is  a  network  of  ridges  inclosing  pits  yt'hich 


544 


FOSSIL   TURTLES    OF    NORTH    AMERICA. 


are  3  mm.  or  less  in  diameter.  On  the  outer  ends  of  these  costals  the  pits  are  even  smaller, 
and  are  arranged  more  or  less  in  rows  across  the  costals.  On  the  nuchal  the  pits  are  small  and 
shallow. 

To  this  species  is  referred  the  specimen  represented  by  fig.  702.  It  was  collected  by  the 
American  Museum  expedition  into  the  Bridger  deposits  in  1903.  The  more  exact  locality 
is  the  eastern  part  of  Grizzly  Buttes,  Wyoming.     The    number  of  the  specimen  is  5910. 

Only  small  portions  of  the  carapace  are  missing.  The  median  region  of  the  nuchal  is 
gone,  and  the  second  and  third  neurals.  There  are  8  pairs  of  costal  plates,  but  the  eighth  pair 
is  vestigial  and  might  therefore  be  missing  in  other  individuals  of  the  same  species.  The 
total  length  of  the  carapace  is  286  mm.,  the  width  almost  exactly  the  same.  Originally  the  upper 
surface  may  have  been  about  as  convex  as  the  carapace  of  Platypeltis  ferox,  of   Florida. 

There  is  no  preneural.  The  length  of  the  first  neural  is  50  mm.;  its  width  anteriorly, 
31  mm.,  posteriorly,  16  mm.  The  fourth  neural  is  29  mm.  long,  18  mm.  wide.  The  fifth  is 
25  mm.  long,  14  mm.  wide.  The  sixth  neural  is  pointed  behind,  17  mm.  long  and  of  about  the 
same  width.  It  permitted  the  costals  of  the  sixth  pair  to  meet  in  the  midline  behind  it.  It  is 
uncertain  whether  or  not  there  was  a  small  seventh  neural. 


701. 


Figs.  701  and  702. — Platypeltis  heteroglypta.     Carapaces.     X  J. 
701.  Carapace  of  type.  702.  Carapace  of  No,  5910  A.  M.  N.  H. 

The  nuchal  of  this  specimen  is  of  greater  extent  fore  and  aft  than  in  the  type,  being  about 
33  mm.  The  distal  ends  past  beneath  the  border  of  the  first  costal  plate,  but  apparently  not 
beneath  the  rib  of  that  costal.  The  free  ends  of  the  carapacial  ribs  projected  beyond  the  mar- 
gin of  the  shell  about  27  mm. 

The  sculpture  resembles  closely  that  of  the  type  specimen,  consisting  of  large  cells  on  the 
neurals  and  the  proximal  ends  of  the  costals  and  of  smaller  cells  on  the  distal  ends  of  the 
costals.  On  the  distal  ends  of  the  costals  the  cells  are  arranged  somewhat  in  rows  parallel 
with  the  adjacent  border  of  the  carapace. 

Any  possible  doubts  regarding  the  specific  position  of  the  specimen  would  arise  from  the 
fact  that  the  nuchal  is  somewhat  broader  from  front  to  back  than  in  the  type;  that  the  costals 
are  somewhat  thinner,  being  only  about  5  mm.;  and  that  the  free  ends  of  the  costals  are 
beveled  down  to  an  acute  edge,  instead  of  being  more  or  less  obtuse  as  in  the  type.  The  dis- 
tance from  the  hinder  border  of  the  carapace  to  the  suture  between  the  second  and  third 
costals  is  almost  the  same  in  the  two  specimens  under  consideration;  but  the  width  of  the 
carapace  of  the  recently  acquired  specimen  is  about  30  mm.  greater  than  in  Cope's  type. 

It  is  not  believed  that  these  differences  indicate  a  distinct  species.  The  thinness  of  the 
bones  may  be  due  to  pressure  during  the  early  stages  of  fossilization;  the  greater  width  of  the 
carapace  to  a  more  advanct  age. 


Neural. 

Length. 

Width. 

57 

3' 

35 

»5        1 

36 

*5 

33 

^3 

3' 

18 

»7 

16 

7 

16 

"        1 

TRIONYCHID^.  545 

Platypeltis  postera  sp.  nov. 
Plate  III,  figs.  I,  2. 

The  type  of  this  species  is  No.  6133  of  the  American  Museum.  It  was  collected  by  the 
museum's  expedition  of  1905,  at  Sage  Creek  Springs,  Wyoming,  in  deposits  belonging  to  the 
level  known  as  C,  therefore  somewhat  above  the  level  of  the  specimens  of  P.  heteroglypta,  its 
nearest  relative.  The  length  of  the  carapace  (plate  11 1,  fig.  l)  in  a  straight  line  is  315  mm.; 
the  greatest  width,  342  mm.  The  upper  surface  is  strongly  convex  from  front  to  the  rear  and 
from  side  to  side.  This  form  is  certainly  natural.  The  nuchal-  is  39  mm.  from  front  to  rear, 
182  mm.  from  side  to  side.  There  is  no  smooth  band  along  its  front.  The  7  neurals  are  all 
present,  and  have  the  dimensions  shown  in  the  table.  The  seventh  partly  separates  the 
costals  of  the  seventh  pair.    Behind  this  these  costals  join  along  the  midline  a  distance  of  57mm. 

The  left  one  of  the  pair  measures  along  the  free  hinder  border  80 
mm.  The  costals  are  thicker  than  in  either  of  the  specimens  of 
P.  heteroglypta  but  this  may  be  due  to  its  being  an  older  indi- 
vidual. At  their  distal  ends  and  near  the  suture  they  are  9  mm. 
thick.    These  ends  are  abruptly  beveled  or  truncated. 

The  sculpture  is  better  displayed  than  in  P.  heteroglypta. 
No.  5910,  but  has  the  same  general  character.  It  differs,  how- 
ever, in  that  the  ridges  between  the  pits  are  narrower  and 
sharper.  It  consists  of  pits,  which  are  very  large  on  the  neurals 
and  the  proximal  ends  of  the  costals,  much  smaller  on  the  distal 
ends  of  the  costals  and  on  the  front  of  the  nuchal.  In  the  median 
region  there  are  3  pits  in  a  line  13  mm.  long.  Occasionally  they  are  slightly  larger  than  this. 
On  the  distal  ends  of  the  costals  there  are  about  5  pits  in  the  line  indicated. 

The  plastron  (plate  1 11,  fig.  2)  lacks  only  the  entoplastron,  the  epiplastra,  and  the  outer 
ends  of  the  right  hyoplastron  and  hypoplastron.  The  form  and  relative  size  of  the  various  bones 
may  be  determined  from  the  plate.  The  hyoplastra  are  solidly  co-ossified  with  the  hypoplastra. 
The  lower  surface  of  all  these  bones  is  covered  with  the  sculptured  layer.  Everywhere,  except 
on  the  outer  ends  of  the  hyoplastra  and  hypoplastra,  the  pits  are  nearly  obsolete.  On  the  outer 
ends  of  the  bones  mentioned  there  are  about  5  pits  in  a  15  mm.  line.  The  line  along  which  the 
hyoplastron  and  hypoplastron  are  united  is  180  mm.  The  bridge  is  64  mm.  wide.  The  bones 
are  about  12  mm.  thick. 

A  specimen.  No.  5955  of  the  American  Museum,  was  collected  in  1906  at  Grizzly  Buttes, 
Wyoming.  It  is  smaller  than  the  type;  but  the  nuchal  resembles  that  of  the  latter,  having  the 
sculptured  layer  covering  the  whole  upper  surface. 

This  species  is  certainly  closely  related  to  P.  heteroglypta.  The  shell  was  probably  more 
convex  in  life  than  that  of  the  latter  species.  The  bones  are  thicker  and  the  free  borders  are 
more  abruptly  cut  off  than  in  P.  heteroglypta.  The  nuchal  is  longer  from  side  to  side  and 
there  is  no  smooth  band  along  the  free  border.  Nor  is  there  a  smooth  band  of  any  considerable 
width  on  the  free  ends  of  the  costals,  as  there  is  in  both  specimens  of  P.  heteroglypta. 

Platypeltis  extensa  sp.  nov. 
Plate  iii;  text-fig.  703. 

The  species  here  described  is  represented  by  only  an  imperfect  carapace  and  plastron 
which  were  secured  by  the  writer  during  the  summer  of  1903,  in  the  Bridger  deposits  of  the 
western  part  of  Grizzly  Buttes,  Wyoming.  When  discovered  the  specimen  was  much  broken. 
The  fragments  have  been  fitted  together  with  all  possible  care,  with  the  result  that  the  form 
and  the  essential  structure  of  the  shell  are  revealed.  A  considerable  area  near  the  front  of 
the  carapace  is  yet  missing;  likewise  a  portion  of  the  rear.  The  position  and  extent  of  the 
missing  portions  are  shown  by  the  figure  on  plate  112.  The  catalog  number  of  the  type  is 
5951  of  the  American  Museum  of  Natural  History. 

In  form  the  carapace  is  broader  than  long,  with  a  broad  and  somewhat  rounded  front  and 
a  broadly  truncated  hinder  end.  The  upper  surface  possest  a  moderate  convexity,  and  this 
is  probably  not  different  from  the  form  in  life.  The  total  length  is  300  mm.;  the  width,  345 
mm.  Apparently  there  were  present  only  7  pairs  of  costal  plates.  Posteriorly  the  bone  is 
present  nearly  to  the  midline;   and  in  case  there  were  8  pairs  of  costals  the  posterior  must 

35 


546 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


Fig.  703. — FJatypehis  extensa.      Cara- 
pace of  type.     X  I- 


have  been  quite  vestigial.  The  costals  of  the  first  pair  are,  at  their  proximal  ends,  much 
wider  fore  and  aft  than  those  behind  them,  being  about  53  mm.  wide,  and  they  increase  in  width 
toward  their  distal  ends.     The  third  and  fourth  costals  are  narrow  at  their  proximal  ends, 

being  respectively  36  mm.  and  33  mm.  wide,  and  they 
expand  little  toward  the  distal  ends.  The  fifth  and  sixth 
are  likewise  narrow  proximally,  but  they  expand  rapidly 
toward  the  margins  of  the  carapace.  The  seventh  cos- 
tals extend  on  each  side  about  66  mm.  from  the  midline. 
The  free  ends  of  the  costal  ribs  extend  little,  if  any, 
beyond  the  margins  of  the  carapace,  thus  aftording  evi- 
dence that  the  individual  was  an  aged  one. 

The  carapace  is  thick  and  solid.  Near  the  proximal 
ends  the  costals  are  6.5  mm.  thick  and  this  thickness 
increases  toward  the  margins  of  the  carapace,  where  it 
amounts  to  8  mm.  in  front  and  behind,  and  to  12  mm. 
and  even  15  mm.  at  the  sides.  The  borders  of  the  cara- 
pace are  not  beveled  off  as  in  many  species.  Anteriorly 
and  posteriorly  the  edge  is  rounded;  at  the  sides  the 
upper  layer  of  bone  overhangs  the  lower,  and  a  groove 
runs  along  between  them. 

There  was  probably  no  preneural.  The  first  neural 
is  missing,  but  the  proximal  border  of  the  left  first  costal 
indicates  that  the  neural  was  long  and  narrow,  with  the 
narrower  end  forward.  Only  a  fragment  of  the  second 
neural  remains.  The  third  neural  had  a  maximum  width 
of  about  23  mm.;  the  fourth  a  width  of  20  mm.;  the  fifth 
a  width  of  17  mm.  The  more  posterior  neurals  have  not 
been  preserved. 

The  nuchal  bone  is  relatively  small.  Its  lateral  extent  is  158  mm.;  its  fore-and-aft  measure- 
ment, 29  mm.  The  outline  of  the  anterior  border  is  nearly  straight,  and  the  immediate  edge 
is  rounded  and  about  7  mm.  thick. 

The  sculpture  of  P.  extensa  resembles  closely  that  of  P.  heteroglypta,  consisting  of  large 
pits,  about  two  in  a  line  10  mm.  long,  on  the  neurals  and  the  proximal  ends  of  the  costals,  and 
of  smaller  cells,  three  in  10  mm.,  on  the  distal  ends  of  the  costals.  The  large  pits  have  broad, 
low,  and  rounded  walls  surrounding  them,  while  the  walls  of  the  smaller  pits  are  more  sharply 
defined.  On  the  outer  ends  of  the  costals  the  pits  show  some  tendency  to  arrange  themselves 
in  rows  parallel  with  the  margins  of  the  carapace. 

This  species  differs  from  P.  heteroglypta  in  its  greater  breadth  as  compared  with  the  length, 
and  in  the  thickened  and  grooved  lateral  borders  of  the  carapace. 

The  left  hyoplastron  and  hypoplastron  are  complete,  except  the  tips  of  the  outer  processes. 
The  two  bones  are  thoroly  co-ossified.  The  sculptured  layer,  the  callosities,  extends  to 
the  midline.  The  length  of  the  hyohypoplastral  suture  is  176  mm.  The  width  of  the  bridge 
is  62  mm.  Here  the  thickness  of  the  hypoplastron  is  1 1  mm.  The  hyoplastron  is  somewhat 
thinner.  Near  the  inner  end  of  the  anterior  border  of  the  latter  bone  there  is  a  deep  notch  for 
the  entoplastron.  At  the  hinder  outer  angle  of  the  hypoplastron  is  a  notch  for  a  process  of  the 
xiphiplastron.  The  humerus  differs  only  in  details  from  that  of  P.  spinijera.  Its  total  length 
is  87  mm. 

Platypeltis  leucopotamica  (Cope). 

Plate  113,  figs.  1-3;   text-fig.  704. 

Trtonyx  leucopotamicus,  CoPE,  Contrib.  Canad.  Palxont.,  ill  (4  to),  1891,  p.  5,  plate  i,  figs.  8,  9. — Ami, 

Science  (i),  xviii,  1891,  p.  53. — Hay,  Bibliog.  and  Cat.  Fo.ss.  Vert.  N.  A.,  1902,  p.  454. 
Trtonyx  punctiger,  CoPE,  Contrib.  Canad.  Palaeont.,  Ill  (410),  1891,  p.  5. — Hay.  loc.  cit.,  p.  454. 

The  type  of  this  species  is  a  fragment  of  a  costal  plate  33  mm.  long  and  25  mm.  wide, 
which  was  found  in  the  White  River  deposits  of  the  Cypress  Hills,  District  of  Alberta,  British 
America.  Professor  Cope's  description  was  reinforced  by  some  fragments  of  what  he  regarded 
as  the  same  species,  which  he  had  obtained  in  the  White  Buttes  of  North  Dakota.    One  of 


TRIONYCHID^. 


547 


Fig.    704. — Platypeltts    leucopotamica. 
Carapace.  X  s-  No.  6045  A.M. N.H. 


these  fragments,  a  piece  of  a  costal,  was  figured  in  the  report  above  cited.  The  larger  piece 
of  costal  which  Cope  figured  belongs  to  the  Geological  Survey  of  Canada,  and  the  present 
writer  has  been  enabled  to  study  it  and  compare  it  with  the  carapace  to  be  here  described. 

In  the  collection  of  the  American  Museum  of  Natural 
History,  there  is  the  nearly  complete  carapace  of  a  triony- 
chid  which  is  with  confidence  referred  to  Cope's  species. 
This  specimen,  No.  6045  (p'ate  1 13;  text-fig.  704)  was 
found  in  the  Titanotherium  beds  of  the  Hat  Creek  Basin, 
Nebraska,  by  Dr.  J.  L.  Wortman,  of  the  American 
Museum's  expedition  of  1894.  This  carapace  was  much 
fractured  and  required  much  skill  and  patience  on  the 
part  ot  the  preparator  to  restore  it.  Portions  of  the  costals 
of  the  right  side  are  missing;  but  the  left  side  is  complete, 
as  well  as  the  whole  margin  of  the  right  side.  It  is  pos- 
sible that  there  were  originally  eight  pairs  of  costals  pres- 
ent, but  the  hinder  border  of  the  costals  of  the  seventh 
pair  appear  to  have  a  smooth  edge,  as  if  having  formed 
a  portion  of  the  free  border  of  the  shell.  As  in  P.  hetero- 
glypta,  there  is  a  neural  between  anterior  borders  of  the 
costals  of  the  last  pair  present,  and  there  is  a  notch  in 
the  midline  behind  which  may  have  lodged  a  small 
eighth  neural.  This  region  resembles  much  that  o{  Pla- 
typeltts spmtfera,  of  North  America. 

The  carapace  is  broad,  slightly  concave  in  front,  and 
slightly  notcht  behind.  The  bones  are  thin  and  light, 
indicating  an  animal  that  lived  in  quiet  waters.  This  is  likewise  shown  by  the  fineness  of  the 
matrix  inclosing  it. 

The  length  of  the  carapace  is  close  to  325  mm.;  the  greatest  breadth  is  353  mm.  The 
shell  is  now  quite  flat,  but  it  was  originally  probably  moderately  convex.  The  thickness  of 
a  costal  plate  at  the  sutural  border  and  in  the  middle  of  the  length  is  only  5  mm.  or  6  mm.;  but 
thru  the  rib  it  is  7  mm.  or  8  mm.  All  around  the  border  the  shell  is  beveled  oft".  The  upper, 
or  proximal,  border  of  the  bevel  is  concave,  so  that  a  broad,  shallow  groove  runs  around  nearly 
the  whole  carapace.  Nowhere  does  the  sculptured  layer  overhang  the  deeper  layers  of  the  bone. 
Posteriorly  the  shell  thins  out  to  a  blunt  edge. 

The  ribs  are  very  distinctly  markt  out  on  the  lower  side  of  the  costal  plates,  and  they  occupy 
at  least  half  of  the  width  of  each  costal.  They  appear  to  have  projected  beyond  the  borders  of 
the  costal  plates  only  about  15  mm. 

The  nuchal  bone  has  a  fore-and-aft  extent  of  38  mm.,  a  transverse  extent  of  212  mm.  At  its 
outer  border  it  overlaps  the  anterior  edge  of  the  first  pair  of  costals. 

There  are  present  7  neural  plates.  In  general,  these  are  broader  behind  than  in  front. 
The  anterior  is  much  larger  than  any  of  the  others.  There  is  no  indication  of  a  preneural. 
The  front  end  of  the  first  neural  is  broadest,  and  its  anterior  outer  angles  bound  portions  of 
2  small  fontanels  which  lie  behind  the  nuchal.     The  fifth  neural  is  quadrilateral,  the  sixth  is 

coflnn-shaped,  with  the  broad  end  foi-ward,  and  the  seventh  is 
hexagonal  and  short.  The  table  gives  the  dimensions  of  the 
various  neural  plates. 

The  distal  ends  of  the  various  costals  display  considerable 
diversity  in  their  widths;  and  in  the  specimen  in  hand  those  of 
the  same  pair  differ  in  some  cases  on  the  opposite  sides.  These 
variations  may  be  observed  on  plate  113. 

The  sculpture  of  this  species  varies  within  narrow  limits  in 
different  parts  of  the  carapace;  as  indeed  it  does  in  all  species. 
Here,  as  in  other  cases,  it  is  coarser  on  the  hinder  parts  of  the 
shell.  In  general,  it  agrees  closely  with  the  type  specimen.  It  consists  of  squarish,  roundish, 
or  oval  pits,  inclosed  by  rather  sharp  ridges,  which  are  narrower  than  the  pits  themselves. 
On  the  neurals  and  on  a  narrow  strip  on  each  side  of  these  (plate  113,  fig.  2),  and  again  near 


Neural. 

Length. 

Width. 

J 

65 

33 

2 

40 

33 

3 

45 

28 

4 

4> 

^5 

S 

33 

17 

6 

i? 

'9 

7 

18 

16 

548  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

the  outer  ends  of  the  costals  (fig.  3  of  plate  1 13),  the  pits  arrange  themselves  more  or  less  in 
rows  parallel  with  the  length  of  the  animal.  On  an  average  there  are  about  8  pits  in  a  line  of 
25  mm.  Near  the  middle  line  posteriorly  some  of  the  pits  may  have  twice  the  average  size, 
but  this  is  unusual.  Along  most  parts  of  the  sutural  borders  of  the  costals  there  is  a  strip 
which  is  almost  devoid  of  sculpture,  except  some  striations  at  right  angles  with  the  suture. 
This  condition  is  most  conspicuous  on  the  proximal  halves  of  the  costals. 

In  a  foot-note  to  the  description  of  his  Trionyx  leucopotamicus  Professor  Cope  has  charac- 
terized a  species,  T .  punctiger,  from  the  White  River  beds  of  Billings  County,  North  Dakota. 
One  of  the  characters  which  are  given  to  distinguish  the  latter  from  the  former  is  the  presence 
of  a  pitless  band  of  surface  along  the  sutural  borders  of  the  costals.  That  is  present  in  the 
specimen  which  has  here  been  described  as  Platypeltis  hucopotamtca,  but  the  writer  can  not 
on  that  account  assign  it  to  T .  punctiger.  The  latter  species  is  said  to  have  the  ridges  of  the 
sculpture  thickened  and  irregular  and  obscure  on  the  outer  ends  of  the  costals.  That  is  not 
true  in  the  carapace  above  described.  T .  punctiger  is  said  to  have  the  shell  thicker  than  that  of 
T .  leucopotamicus.  Cope's  type  of  the  latter  species  has  a  thickness,  thru  the  rib,  of  only 
6  mm.  The  carapace  here  described  from  Nebraska  has  a  thickness  thru  the  ribs  varying 
from  9  mm.  to  1 1  mm.,  which  is  the  thickness  in  the  same  regions  of  T.  punctiger.  It  appears 
to  the  present  writer  that  T .  punctiger  is  identical  with  T .  leucopotamicus;  but  more  materials 
must  be  collected  before  certainty  on  this  point  can  be  obtained. 

It  is  not  known  to  the  writer  where  the  type  of  T .  punctiger  is. 

Professor  Cope  in  his  description  of  this  species  spoke  of  its  close  resemblance  to  Leidy's 
Trionyx  uinta'ensis.  Now  that  we  have  the  complete  carapaces  of  both  species,  it  is  seen  that 
they  are  extremely  different. 

Platypeltis  ferox   (Schneider). 

Trionyx  ferox,  Schneider,  Schiidkrote,  1783,  p.  330;  Boui.enger,  Catalogue  Chelonians,  1889,  p.  259. 
Platypeltis  ferox,  Agassiz,  Contrib.  Nat.  Hist.  U.  S.,  I,  pt.  ii,   1857,  p.  401. 

In  the  Dr.  Jarman  collection  of  fossils  obtained  in  Hillsboro  County,  Florida,  and  now  the 
property  of  the  Vanderbilt  University,  Nashville,  Tennessee,  there  are  several  fragments  of 
plastral  and  carapacial  bones  which  the  writer  can  not  distinguish  satisfactorily  from  corres- 
ponding bones  of  the  above  species,  now  living  in  the  rivers  of  Florida.  With  these  bones  come 
others  which  evidently  belong  to  2  or  3  undescribed  species  of  the  genus;  but  the  fragments 
hardly  justify  the  application  of  systematic  names  to  them.  The  beds  furnishing  these  bones 
are  supposed  to  belong  to  the  Peace  Creek  formation. 

Dr.  Friedrich  Siebenrock  (Sitzber.  Acad.  Wien,  math.-naturw.  CI.,  cxi,  1902,  p.  829) 
regards  this  species  as  identical  with  P.  spinifera.  In  fact  the  two  forms  are  very  distinct. 
P.  ferox  has  the  carapace  much  more  elongated  and  the  sculpture  is  much  coarser.  Their 
geographical  distribution  is  different  also. 


THE  END. 


INDEX. 


Acherontemys,  221 

heckmani,  222 
Achilemys,  373,  383 

allabiata,  383 
Acichelys  crassipes,  57 
acupictus  (Plastomenus),  467,  470 
acutidens  (Holcodus),  187 
admirabilis  (Conchochelys),  483 
Adocids,  224 
Adocus,  224,  225,  226,  236 

agilisj  236,  242^  246 

beatus,  236,  239,  242 

Hrmus,  254 

imbricarius,  231 

lacer^  236,  241,  242 

lineolatus,  236,  247 

pectoralis,  254 

petrosus,  250 

pravus,  236,  242,  246 

punctatus,  236,  242 

syntheticus,  236,  242,  244 

variolosus,  226 

wyomingensis,  271 
advena  (Protostega),  199 
Kgle  (Echmatemys),  298,  331 
aequa  (Arayda),  511,  517 
affinis  (Baena),  67 
agilis  (Adocus),  236,  242,  246 
Agomphus,  224,  225,  226,  248 

firmus,  249,  254 

masculinus,  249,  255 

oxysternum,  249,  256 

pcctoralis,  249,  254 

petrosus,  249,  250 

tardus,  249,  252 

turgidus,  249 
Alamosemys,  226,  260 

substricta,  260 
allabiata  (Achilemys),  383 
allabiatus  (Hadrianus),  383 
Allopleuron  hoffmanni,  209 
Amblypeza,  102,  122 

entellus,  122 
amnicola  (Platypeltis),  536,  540 
Amphichelydia,  25,  43 
Amphiemys,  248 

oiysternum,  256 
amphithorax  (Testudo),  397,  407 
Amyda,  483,  510 

aqua,  511,  517 

buiei,  511,  534 

cariosa,  511,  515 

cellulosa,  511    534 

concentrica,  511,  522 

crassa,  511,  532 

*^gregia,  511,  531 

exquisita,  511,  525 

francisca?,  511,  523 

halophila,  511,  513 

lima,  511,  533 

mira,  511,  527 

pennata,  511,  514 

36 


Amyda  prisca,  511,  512 

radula,  511,  517 

salebrosa,  511,  524 

scutumantiquum,  511,  521 

tritor,  511,  529 

uintaensis,  51 1,  519 

ventricosa,  511,  516 

virginiana,  511,  515 
anguillulata  (Terrapene),  364,  366,  367 

(Toxaspis),  364 
angusta  (Lytoloma),  155,  157 
Anosteira,  225,  226,  279 

ornata,  279 

radulata,  281 

radulina,  281 
Anoslira  molopinus,  481 

oedemia,  479 

radiolata,  281 

radulina,  281 

trionychoides,  541 
antiqua  (Baena),  62 

(Platypeltis),  536,  537 
Aspidonectes  tritor,  529 
Archa?ochelys,  100 
Archelon,  202 

ischyros,  202 

marshi,  208 
arenaria  (Hybemys),  345 
arenivaga  (Testudo),  398,  430 
arenosa  (Baena),  60,  67,  76 
arethusa  (Echmatemys),  298,  323 
Aspideretes,  483,  485 

austerus,  486,  495 

beecheri,  486,  492 

coalescens,  486,  488 

ellipticus,  486,  505 

fontanus,  486,  494 

foveatus,  486 

granger!,  486,  507 

guttatus,  486,  503 

nassau,  486,  498 

puercensis,  486,  499 

sagatus,  486,  497 

singularis,  486,  501 

splendidus,  486,  490 

vagans,  486,  497 

vorax,  486,  496 
atascosse  (Testudo),  398,  464 
Athecje,  25,  43 
Atlantochelys,  188 

gigas,  190 

mortoni,  188 

tuberosus,  187 
austerus  (Aspideretes),  486,  495 
Axestemys,  483,  508 

byssina,  509 
Axestus,  508 

bysimus,  509 

byssinus,  509 
Baena,  58,  59 

affinis,  67 

anti<[ua,  60,  62 


549 


550 


INDEX. 


Baena  arenosa,  60,  67,  76,  79 

callosa,  60,  61 

cephalica,  82 

clara,  60,  74 

emilia",  60,  80 

escavada,  60,  65 

hatchcri,  60,  63,  92 

hcbraica,  87 

marshi,  60,  61,  62 

ponderosa,  271 

pulchra,  92 

riparia,  60,  76 

sima,  60,  71 

undata,  85,  87 
Bacnida",  45,  56 
Baptcmys,  224,  225,  226,  270 

costilatus,  267 

fluviatilis,  277 

tricarinata,  275 

wyomingensis,  270 
Basilemys,  224,  225,  226, 

imbricaria,  231 

ogmius,  226 

sinuosa,  229 

variolosa,  226 
bauri  (Toxochelys),  168,  178 
beatus  (Adocus),  236,  239,  241,  242 

(Emys),  239 
beechcri  (Aspidcretcs),  486,  492 
belviderensis  (Glyptops),  53 

(Plesiochelys),  53 
bisornata  (Trachemys),  348,  353 
bisornatus  (Pseudemys),  353 
borealis  (Osteopygis),  128,  141 

(Propleura),  141 
Boremys,  58,  91 

pulchra,  92 
Bothremydida',  102 
Bothremys,  102 

cooki,  103,  105 

molops,  115 
brachyrhina  (Tosochelys),  168,  171 
Bridger  epoch,  turtles  of,  37,  39 
brontops  (Testudo),  397,  398 
browni  (Porthochelys),  182 
buiei  (Amyda),  511,  534 

(Trionyx),  534 
bysimus  (Axestus),  509 
byssina  (Axestemys),  509 
byssinus  (Axestus),   509 
Ctelata  (Pseudemys),  356 
ca?latus  (Glyptops),  52 
calaverensis  (Stylemys),  386,  396 
callopyge  (Echmatemys),  298,  340 
caliosa  (Baena),  60 
campester  (Testudo),  398,  455 
canaliculata  (Terrapene),  360,  363 
capax  (Stylemys),  386,  392 
captans  (Charitemys),  98 
Caretta,  8,  10 
Carettochelys,  19 
cariosa  (Amyda),  511,  515 
cariosus  (Trionyx),  516 
carteri  (Emys),  376 
Caryoderma  snovianum,  438 
Cataplcura,  127,  128,  150 

chelydrina,  136 

ponderosa,  152 

repanda,  150 
catenatus  (Plastomcnus),  467,  470 
cellulosa  (Amyda),  ^ir.  534 
cellulosus  (Trionyx),  534 
Cenozoic,  turtles  of,  38 
cephalica  (Baena),  82 

(Eubaena),  82 
Charitemys,  58,  98 


Charitemys  captans,  98 
Chelone  crassicostata,  154,  160 

ornatus,  210 

parviscutatus,  220 

parviscutum,  220 

parvitecta,  220 

planimentum,  154 

sopita,  149,  155 
Chelonia,  209,  220 

granda^va,  216 

parvitecta,  220 
Cheloniida-,  8,  9,  19,  208 
Chelydosauria,  28 
Chelydra,  223 

crassa,  263 

serpentina,  223 
ChelydridcC,  32,  221 
chelydrina  (Cataplcura),  136 
chelydrinus  (Osteopygis)    128,  136 
Chisternon,  57,  58,  84 

hcbraicum,  87 

undatum,  85 
Chrysemys,  287,  288,  345 

inornata,  358 

timjda,  345 

wyomingensis,  308 
cibollensis  (Echmatemys),  298,  300 

(Emys),  300 
Cistudo  eurypygia,  364 

marnochii,  362 
clara  (Baena),  60,  74 
Classification  of  turtles,  25 
Claudius,  224,  225 
Clemmys,  286,  287,  290 

hesperia,  290,  292 

insculpta,  290,  295 

morrisiae,  290 

percrassa,  290,  294 

Eaxea,  290,  294 
coalcscens  (Aspidcretes),  486,  488 

(Plastomenus),  488 

(Trionyx),  488 
communis  (Plastomenus),  467,  473,  481 
Compsemys,  225,  226,  233 

imbricarius,  231 

lineolatus,  247 

obscura,  235 

ogmius,  226 

plicatulus,  47 

variolosus,  226 

victa,  233 
concentrica  (Amyda),  511,  523 
concentricus  (Trionyx),  523 
Conchochelys,  483 

admirabilis,  483 
conspecta  (Stylemys),  386,  393 
cooki  (Bothremys),  103,  105 
corrugatus  (Plastomenus),  467,  473 
corsoni  (Hadrianus),  374,  376 

(Testudo),  376 
costatus  (Plastomenus),  467 
costilata  (Kallistira),  267 
costilatus  (Baptemys),  267 

(Dermatemys),  267 
Cotylosauria,  28 
crassa  (Amyda),  511,  532 

(Chelydra),  263 

(Hoplochelys),  263 
crassicostata  (Chelone),  154 
crassiscutata  (Testudo),  398,  459 
crispatus  (Syllomus),  211 
Cryptodira,  18,  25,  31,  43,  126 
culbertsonii  (Emys),  386 

(Stylemys),  386 

(Testudo),  386 
cultrata  (Testudo),  397,  411 


INDEX. 


551 


cyane  (Echmatemys),  298,  324 
cyclopygia  (Testudo),  438 
cyclopygius  (Xerobates),  438 
Cynocercus,  180 

incisus,  168,  180 
dares  (Taphrosphys),  105,  120 
Deirochelys,  288,  346 

floridana,  346 
depressus  (Glypiops),  55 
Dermatemydidce,  32,  223 
Dermatemys,  224,  225 

costilatus,  267 

mawfi,  284 

vyomingensis,  271 

wyomingensis,  271 

see  also,  263,  275 
Dermochelyidrr,  14 
Dermochelys,  14,  17,  19,  23 
Desmatochelyida',  184 
Desmatocheiys,  184 

lowi,  185 
distincta  (Helopanoplia),  485 
Distribution,  30 
Echmatemys,  287,  295 

acgle,  298,  331 

arethu&a,  298,  323 

callopyge,  298,  340 

cibollensis,  298,  300 

cyane,  298,  324 

euthneta,  298,  305 

haydeni,  298,  308,  313 

latilabiata,  298,  339 

lativertebralis,  298 

megaulas,  298,  301 

naomi,  298,  335 

ocyrrhoe,  298,  329 

pusilla,  298,  337 

septaria,  298,  319 

shaughnessiana,  298,  327 

stevensoniana,  298,  316 

testudinea,  298,  303 

uintensis,  298,  342 

wyomingensis,  298,  308 
edae  (Testudo),  398,  450 
egregia  (Amyda),  511,  531 
elkader  (Toiochelys),  i58,  174 
ellipticus  (Aspideretes),  486,  505 
emarginatus  (Osteopygis),  128,  129 
emilite  (Baena),  60,  80 

(Testudo),  398,  419 
Emydidie,  2,  33,  284 
Emys,  286 

beatus,  239 

carteri,  376 

cibollensis,  300 

culbertsonii,  386 

euglypha,  350 

euthneta,  305 

firmus,  254 

gravis,  269 

haydeni,  308,  313 

hemispherica,  318,  386 

jeanesi,  308 

jeanesianus,  308 

lata,  386 

latilabiatus,  298,  339 

lativertebralis,  298 

niegaulax,  301 

nebrascensis,  386 

obscurus,  235 

oweni,  386 

pachylomus,  301,  302 

parva,  246 

petrolei,  352 

petrosus,  250 

polycypha,  343 


Emys  pravus,  246 

septaria,  319 

shaughnessiana,  327 

stevensoni,  316 

stevensonianus,  300,  316 

terrestris,  344 

testudineus,  303 

turgidus,  249 

vyomingensis,  308 

wyomingensis,  308,  313,  316,  337 
enodis  (Prochonias),  115 

(Taphrosphys),  115 
entellus  (Amblypeza),  122 
erosus  (Osteopygis),  128,  138 
Eniuelinnesia,  127,  i6o 

gosseleti,  160 

moiaria,  160 
escavada  (Bacna),  60,  65 
Eubaena,  58,  82 

cephalica,  82 

latifrons,  83 
Euclastes,  161 

platyops,  162 
euglypha  (Emys),  350 

(Trachemys),  348,  350 
Eupachemys  obtusa,  458 

rugosus,  458 
Europe,  turtles  of,  40 
eurypygia  (Cistudo),  364 

(Terrapene),  360,  364 
euthneta  (Echmatemys),  298,  305 

(Emys),  305 
eximius  (Neurankylus),  94 
exornata  (Testudo),  397,  401 
exquisita  (Amyda),  511,  525 
extensa  (Platypeltis),  537,  545 
extincta  (Pseudemys),  356 
Families  of  turtles,  25 
farri  (Testudo),  398,  418 
ferox  (Platypeltis),  537,  548 

(Trionyx),  548 
firmus  (Adocus),  254 

(Agomphus),  249,  254 

(Emys),  254 
fioridana  (Deirochelys),  346 

(Macrochelys),  222 
fluviatilis  (Baptemys),  277 
fontanus  (Aspideretes),  486,  494 
Formosa  (Xenochelys),  282 
foveatus  (Aspideretes),  486 

(Trionyx),  486,  492 
fractus  (Plastomenus),  467,  472 
franciscff  (Amyda),  511,  523 
Galapagos  Islands,  origin  of,  371 
garmanii  (Notomorpha),  269 
Geographical  distribution,  30 
Geological  distribution,  36 
gibbi  (Osteopygis),  128,  132 
gigas  (Atlantochelys),  190 

(Protostega),  190 
gilbert!  (Testudo),  398,  449 
Glyptops,  45 

belviderensis,  53 

ca'latus,  52 

depressus,  55 

ornatus,  47 

pervicax,  54 

plicatulus,  47 
gosseleti  (Erquelinnesia),  160 
granda;va  (Chelonia),  216 

(Procolpochelys),  216 
grandiCvus  (Puppigerus),  216 
grangeri  (Aspideretes),  486,  507 
Graptemys,  288,  358 

inornata,  358 
gravis  (Emys),  269 


552 


INDEX. 


gravis  (Notomorpha),  269 

Greensand  of  New  Jersey,  turtles  of,  37 

guttatus  (Aspideretes),  486,  505 

(Trionyx),  503 
Gyremys,  287,  288 

spectabilis,  288 
Hadrianus,  36R,  373 

allabiatus,  383 

corsonii,  374,  376 

majusculus,  374 

octonarius,  376 

quadratus,  376 

schucherti,  374,  382 

tumidus,  374,  380 
hadrianus,  (Testudo),  376 
halophila  (Amyda),  511,  513 
halophilus  (Trionyx),  513 
hatcheri  (Bacna),  63,  92 
haydeni  (Echmatemys),  298,  313 

(Emys),  308,  313 
hebraica  (Baena),  87 
hebraicum  (Chisternon),  87 
heckmani  (Acherontcmys),  222 
Helochelys,  46 
Helopanoplia,  483,  485 

distincta,  485 
hemispherica  (Emys),  386 

(Testudo),  386 
hcsperia  (Clemmys),  290,  292 
heteroglypta  (Platypeltis),  537,  543 
heleroglyptus  (Trionyx),  543 
hexagonata  (Testudo),  398,  463 
hilli  (Pseudemys),  348 

(Trachemys),  348 
hofltmanni  (Allopleuron),  209 
Holcodus  acutidens,  187 
hoUandi  (Testudo),  398,  451 
Homorophus,  225,  226,  260 

insuetus,  260 
Hoplochelys,  225,  226,  263 

crassa,  263 

paludosa,  266 

saliens,  265 
Hybemys,  287,  344 

arenaria,  345 
imbricaria  (Basilemys),  231 
imbricarius  (Adocus),  231 

(Compsemys),  231 
impensa  (Testudo),  398,  431 
incisus  (Cynocercus),  180 
ingravata  (Naiadochelys),  125 
inornata  (Chrysemys),  358 

(Graptemys),  358 
insculpta  (Clemmys),  290,  295 

(Testudo),  295 
insignis  (Plastomenus),  467,  469 
insiliens  (Thescelus),  95 
insuetus  (Homorophus),  260 
insularis  (Lembonax),  213 
inusitata  (Testudo),  398,  417 
ischyros  (Archelon),  202 

(Protostega),  202 
jarmani  (Trachemys),  348,  351 
jeanesi  (Emys),  308 

(Lytoloma),  156 

(Propleura),  156 
jeanesianus  (Emys),  308 
Judith  River  epoch,  turtles  of,  36 
Kallistira,  225,  226,  267 

costilata,  267 
klettiana  (Testudo),  398,  436 
lacer  (Adocus),  236,  241 
lachrymalis  (Plastomenus),  467,  472 
Laramie,  turtles  of,  36 
lata  (Emys),  386 

(Testudo),  386 


laticaudata  (Testudo),  398,  461 
laticeps  (Porthochelys),  180 
laticunea  (Testudo),  397,  402 
latifrons  (Eubaena),  83 
latilabiata  (Echmatemys),  298,  339 

(Emys),  298,  339 
latiremis  (Toxochelys),  166,  168 
lativertebralis  (Echmatemys),  298 

(Emys),  298 
Lembonax,  209,  212 

insularis,  213 

polemicus,  212 

prophylaeus,  214 

propylaeus,  214 
Lepidochelys,  8,  9,  10,  216 
leptomitis  (Plastomenus),  467,  470 

(Trionyx),  470 
leslianus  (Taphrosphys),  105,  in 

(Prochonias),  1 11 
leucopotamica  (Platypeltis),  537,  546 
leucopotamicus  (Trionyx),  546 
ligonia  (Testudo),  397,  405 
lima  (Amyda),  511,  533 

(Trionyx),  533 
Limbs,  structure  of,  7,  9,  11,  12,  14,  16,  24 
lineatus  (Adocus),  236,  247 
lineolatus  (Compsemys),  247 
longinuchus  (Taphrosphys),  105,  108 
lowi  (Desmatochelys),  185 
Lytoloma,  127,  154 

angusta,  155,  157 

crassicostatum,  154,  160 

jeanesi,  156 

platyops,  160,  162 

wielandi,  157 
Macrochelys,  222 

floridana,  222 
majusculus  (Hadrianus),  374 
manducans  (Temnotrionyx),  534 
marnochi  (Cistudo),  362 

(Terrapene),  360,  362 
marshi  (Archelon),  208 

(Baena),  61,  62 
masculinus  (Agomphus),  249,  255 
mawii  (Dermalemys),  284 
megaulax  (Echmatemys),  298,  301 

(Emys),  301 
Mesozoic,  turtles  of,  36 
microglypha  (Zygoramma),  259 
Miocene,  turtles  of,  37 
mira  (Amyda),  511,  527 
missuriensis  (Polythorax),  100 
mitchelli  (Mosasaurus),  188 
molaria  (Erquelinnesia),  160 
molopina,  (Anostira),  481 
molopinus  (Plastomenus),  467,  481 
molops  (Bothremys),  115 

(Taphrosphys),  105,  115 
morrisiae  (Clemmys),  200 
mortoni  (Atlantochelys),  188 
Mosasaurus  mitchelli,  188 
multifoveatus  (Plastomenus),  470,  474 
Naiadochelys,  102,  125 

ingravata,  125 
naomi  (Echmatemys),  298,  335 
Naomichelys,  58,  loi 

speciosa,  loi 
nassau  (Aspideretes),  486,  498 
nebrascensis  (Emys),  386 

(Stylemys),  386,  392,  393 

(Testudo),  386 
Neck,  structure  of,  4,  8,  11,  13,  15,  20 
neptunia  (Protostega),  188 
Neptunochelys,  187 

tuberosa,  187 
Neurankylus,  58,  93 


INDEX. 


553 


Neurankylus  eximius,  94 
Niobrara  epoch,  turtles  of,  36 
niobrarensis  (Stylemys),  437 

(Testudo),  398,  437 
nodosus  (Taphrosphys),  105,  122 
Notomorpha,  225,  226,  269 

garmanii,  269 

gravis,  269 

testudinea,  303 
Number  of  species,  2 
obscura  (Compsemys),  235 
obscurus  (Emys),  235 
obtusa  (Testudo),  398,  458 
obtusus  (Eupachemys),  458 
octonarius  (Hadrianus),  376 
ocyrrhoc  (Echmatemys),  298,  329 
oedemia  (Anostira),  479 
oedemius  (Plastomenus),  467,  479 
ogmius  (Basilemys),  226 

(Compsemys),  226 
oregonensis  (Stylemys),  392 

(Testudo),  392 
Origin  of  turtles,  28 
ornata  (Anosteira),  279 

(Anostira),  279 
omatus  (Chelone),  210 

(Glyptops),  47 

(Peritresius),  210 
orthopygia  (Testudo),  398,  438 

(Xerobates),  438 
osborniana  (Testudo),  398,  422 
Osteology  of  turtles,  2 
Osteopygis,  127 

borealis,  128,  141 

chelydrinus,  128,  136 

emarginatus,  128,  129 

erosus,  128,  138 

gibbi,  128,  132 

platylomus,  128,  129,  146 

ponderosa,  152 

repandus,  150 

robustus,  128,  134 

sopitus,  128,  141,  149 
oweni  (Emys),  386 

(Testudo),  386 
oxysternum  (Agomphus),  249,  256 

(Amphiemys),  256 
pachylomus  (Emys),  301,  302 
Pachyrhynchus,  160 
Palaeotheca,  287,  343 

polycypha,  343 

terrestris,  344 
paludosa  (Hoplochelys),  266 
pansa  (Testudo),  398,  420 
parva  (Emys),  246 
parviscutatus  (Chelone),  220 
parviscutum  (Chelone),  220 

(Puppigerus),  220 
parvitecta  (Chelone),  220 

(Chelonia),  220 
parvitectus  (Puppigerus),  220 
pectorale  (Pleurosternum),  254 
pectoralis  (Adocus),  254 

(Agomphus),  249,  254 
Pelvis,  structure  of,  7,  9,  12,  14,  16,  21 
pennata  (Amyda),  511,  514 
pennatus  (Trionyx),  514 
peragrans  (Testudo),  398,  412 
percrassa  (Clemmys),  290,  294 
Peritresius,  209 

ornatus,  122.  210 
pertenuis  (Testudo),  398,  454 
pervicax  (Glyptops),  54 
petrolei  (Emys),  352 

(Trachemys),  348,  352 
petrosus  (Adocus),  250 


pelrosus  (Agomphus),  249,  250 

(Emys),  250 
Phylogeny  of  turtles,  27,  28 
Pierre  epoch,  turtles  of,  36 
planimentum  (Chelone),  154 
Plastomenidas,  466 
Plastomenus,  466 

acupictus,  467,  470 

catenatus,  467,  470 

coalescens,  488 

communis,  467,  473,  48 1 

corrugatus,  467,  473 

costatus,  467 

fractus,  467,  472 

insignis,  467,  469 

lachrynialis,  467,  472 

leptomitus,  467,  470 

molopinus,  467,  4S1 

multifoveatus,  470,  474 

cedemius,  467,  479 

punctulatus,  467,  468 

serialis,  537 

tantillus,  467,  478 

thomasi,  467,  474,  476,  537 

trionychoides,  541 

visendus,  467,  476 
Platemys  sulcatus,  104,  106 
Platychelys,  59 

platylomus  (Osteopygis),  128,  129,  146 
platyops  (Euclastes),  162 

(Lytoloma),  160,  162 

(Rhetechelys),  162 
Platypeltis,  483,  536 

amnicola,  536,  540 

antiqua,  536,  537 

extensa,  537,  545 

ferox,  II,  537,  548 

heteroglypta,  537,  543 

leucopotamica^  537,  546 

postera,  537,  545 

serialis,  536,  537 

trepida,  536,  541 

trionychoides,  537,  541 
Plesiochelyidae,  45 
Plesiochelys  belviderensis,  53 
Plesiosauria,  30 

Pleurodira,  12,  19,  20,  25,  34,  43,  102 
Pleurosternidce,  45 
PI e u roster non,  46 
Pleurosternum  pectorale,  254 
plicatulus  (Compsemys),  47 

(Glyptops),  47 
polemicus  (Lembonax),  212 
polycypha  (Emys),  343 

(PalEeotheca),  343 
Polythorax,  58,  100 

missuriensis,  100 
ponderosa  (Baena),  271 

(Catapleura),  152 

(Osteopygis),  152 
Porthochelys,  180 

browni,  182 

laticeps,  180 
postera  (Platypeltis),  537,  545 
potens  (Protostega),  189,  198 
pravus  (Adocus),  236,  242,  246 

(Emys),  246 
Preneural  bone,  57 
princeps  (Prochonias),  114 

(Taphrosphys),  114 
prisca  (Amyda),  511,  512 
priscus  (Trionyx),  512 
Probaena,  58 

sculpta,  58 
procax  (Toxochelys),  168,  176 
Prochonias,  104 


554 


INDEX. 


Prochonias  enodis,  115 

leslianus,  1 11 

longinuchus,  108 

princeps,  1 14 

strenuus^  114 

sulcatus,  106 
Procolpochelys,  209,  215 

grandaeva,  216 
Proganochelyidae,  45 
Proganochelys,  45 
prophyl^us  (Lembonax),  214 
Propleura,  127,  128 

borealis,  141 

jeanesii,  156 

repanda,  150 

sopita,  141,  162,  163 
propylaius  (Lembonax),  214 
Protostega,  190 

advena,  199 

gigas,  190 

ischyros,  202 

neptunia,  188 

potens,  189,  198 

tuberosa,  187 
Protostegidcp,  189 
Pseudemys,  288,  356 

bisornatus,  353 

caclata,  356 

extincta,  356 

hiili,  348 
Pseudotrionyx,  19,  225 
puercensis  (Aspideretes),  486,  499 
pulchra  (Baena),  92 

(Boremys),  92 
punctatus  (Adocus),  236 
punctiger  (Trionyx),  546 
punctulatus  (Plastomenus),  467,  468 
Puppigerus,  215 

granda-vus,  216 

parviscutum,  220 

parvitecta,  220 
pusilla  (Echmatemys),  298,  337 
putnami  (Terrapene),  360 
quadrata  (Testudo),  397,  410 
quadratus  (Hadrianus),  376 
radiolata  (Anostira),  281 
radula  (Amyda),  511,  517,  518 
radulata  (Anosteira),  281 
radulina  (Anostira),  281 
radulus  (Trionyx),  517,  518 
rapiens  (Thescelus),  97 
repanda  (Catapleura),  150 

(Propleura),  150 
repandus  (Osteopygis),  150 
Rhetechelys,  127,  161 

platyops,  162 
riparia  (Baena),  60,  76 
robustus  (Osteopygis),  128,  134 
rugosus  (Eupachemys),  458 
sagatus  (Aspideretes),  486,  497 
salebrosa  (Amyda),  511,  524 
saliens  (Hoplochelys),  265 
saxea  (Clemmys),  290,  294 
schucherti  (Hadrianus),  374,  382 
sculpta  (Probacna),  58 

(Trachemys),  348,  351 
Scutes,  horny,  18 
scutumantiquum  (Amyda),  511,  521 

(Trionyx),  521 
septaria  (Echmatemys),  298,  319 

(Emys),  319 
serialis  (Plastomenus),  537 

(Platypeltis),  536,  537 
serpentina  (Chelydra),  223 

(Testudo),  223 
serrifer  (Toxochelys),  168,  170,  172 


shaughnessiana  (Echmatemys),  298,  327 

(Emys),  327 
Shell,  structure  of,  2,  8,  10,  12,  14,  17,  18,  23 
Shoulder-girdle,  6,  9,  11,  13,  16 
sima  (Baena),  71 
singularis  (Aspideretes),  486,  501 
sinuosa  (Basilemys),  229 
Skull,  structure  of,  5,  9,  11,  13,  15,  19,  24 
snoviana  (Testudo),  438 
snovianum  (Caryoderma),  438 
Soft-shelled  turtles,  10 
sopita  (Chelone),  149,  155 

(Osteopygis),  141 

(Propleura),  141,  163 
sopitus  (Osteopygis),  128,  149 
speciosa  (Naomichelys),  101 
spectabilis  (Gyremys),  288 
splendidus  (Aspideretes),  486,  490 
Staurotypus,  224,  225 
stenopora  (Toxochelys),  168,  172 
stevensoni  (Emys),  316 
stevensoniana  (Echmatemys),  298,  316 
Steven sonianus  (Emys),  300,  316 
slrenuus  (Prochonias),  114 

(Taphrosphys),  105,  114 
striatula  (Zygoramma),  257 
Stylemys,  369,  373,  385 

calaverensis,  386,  396 

capax,  386,  392 

conspecta,  386,  393 

culbertsonii,  386 

nebrascensis,  386,  392,  393 

niobrarensis,  437 

oregonensis,  39Z 
Suborders  of  turtles,  25 
substricta  (Alamosemys),  260 
sulcatus  (Platemys),  104,  105,  106 

(Prochonias),  106 

(Taphrosphys),  105,  106 
Supernumerary  scutes,  57 
Syllomus,  209,  211 

crispatus,  21 1 
syntheticus  (Adocus),  236,  242,  244 
tantillus  (Plastomenus),  467,  478 
Taphrosphys,  102,  104 

dares,  105,  120 

leslianus,  105,  11 1 

longinuchus,  105,  108 

molops,  105,  1 15 

nodosus,  105,  122 

princeps,  1 14 

strenuus,  105,  1 14 

sulcatus,  105,  122 
tardus  (Agomphus),  249,  252 
Temnotrionyx,  534 

manducans,  534 
Terrapene,  286,  288,  359 

anguillulata,  364,  366,  367 

canaliculata,  360,  363 

eurypygia,  360,  364 

marnochi,  360,  362 

putnami,  360 
terrestris  (Emys),  344 

(Palseotheca),  344 
testudinea  (Echmatemys),  298,  303 

(Emys),  303 

(Notomorpha),  303 
TestudinidcP,  33,  367 
Testudines,  definition  of,  43 
Testudo,  367,  372,  373,  397 

amphithorax,  397,  407 

arenivaga,  398,  430 

atascosae,  398,  464 

brontops,  397,  398,  400 

campester,  398,  455 

corsoni,  376 


INDEX. 


555 


Testudo  crassiscutata,  398,  459 

culbertsonii,  386 

cultrata,  397,  411 

cyclopygia,  438 

edse,  398,  450 

emilia",  398,  419 

exornata,  397,  401 

farri,  398,  418 

gilberti,  398,  449 

hadrianus,  376 

hemispherica,  386 

hexagonata,  398,  463 

hollandi,  398,  451 

impensa,  398,  431 

insculpta,  295 

inusitata,  398,  417 

klettiana,  398,  436 

lata,  386 

laticaudata,  398,  462 

laticunea,  397,  402 

ligonia,  397,  405 

nebrascensis,  386 

niobrarensis,  398,  437 

obtusa,  398,  458 

oregonensis,  392 

orthopygia,  398,  438 

osbormana,  398,  422 

oweni,  386 

pansa,  398,  420 

peragrans,  398,  412 

pertenuis,  398,  454 

quadrata,  397,  410 

snoviana,  438 

serpentina,  223 

thomsoni,  397,  400 

turgida,  398,  453 

undata,  398,  435,  438 

vaga,  398,414 
Thalassemydidae,  126,  127 
Thecophora,  43 
Thescelus,  58,  94 

insiliens,  95 

rapiens,  97 
thomasi  (Plastomenus),  467,  474,  476,  537 

(Trionyx),  474 
thomsoni  (Testudo),  397,  400 
timida  (Chrysemys),  345 
Toxaspis  anguillulata,  364 
Toxochelyida;,  163 
Toxochelys,  163 

bauri,  168,  178 

brachyrhina,  168,  171 

elkader,  168,  174 

latiremis,  166,  168 

procax,  168,  176 

scrrifer,  168,  170,  172 

stenopora,  168,  172 
Trachemys,  288,  347 

bisornata,  348,  353 

euglypha,  348,  350 

hilli,  348 

jarmani,  348,  351 

petrolei,  348,  352 

sculpta,  348,  351 

trulla,  348,  355 
trepida  (Platypeltis),  536,  541 
tricarinata  (Baptemys),  275 
TrionychidEe,  18,  35,  483 
Trionychoidea,  10,  17,  20,  25,  43,  465 
trionychoides  (Anostira),  541 

(Plastomenus),  541 

(Platypeltis),  537,  541 
Trionyx,  10,  17 


Trionyx  buiei,  534 

cariosus,  51  ^ 

cellulosus,  534 

coalescens,  488 

concentricus,  523 

ferox,  548 

foveatus,  486,  492 

guttatus,  503 

halophilus,  513 

heteroglyptus,  543 

leptomitus,  470 

leucopotamicus,  546 

lima,  533 

pennatus,  514 

priscus,  512 

punctiger,  547 

radulus,  517 

scutumantiquum,  521 

thomasi,  474 

uintaensis,  51  9 

vagans,  488,  490,  497 

ventricosus,  516 

virginianus,  515 
tritor  (Amyda),  511,  529 

(Aspideretes),  529 
trulla  (Trachemys),  348,  355 
tuberosa  (Neptunochelys),  187 

(Protostega),  187 
tuberosus  (Atlantochelys),  187 
tumidus  (Hadrianus),  374,  380 
turgida  (Testudo),  398,  453 
turgidus  (Agomphus),  249 

(Emys),  249 
uintaensis  (Amyda),  511,  519 

(Trionyx),  519 
uintensis  (Echmatemys),  298,  342 
undata  (Baena),  85,  87 

(Testudo),  398,  435,  438 

(Xerobates),  449 
undatum  (Chisternon),  85 
vaga  (Testudo),  398,  414 
vagans  (Aspideretes),  486,  497 

(Trionyx),  488,  490,  497 
variolosa  (Basilemys),  226 
variolosus  (Adocus),  226 

(Compsemys),  226 
ventricosa  (Amyda),  511,  516 
ventricosus  (Trionyx),  516 
VerlebrEE  of  turtles,  4,  8,  12 
victa  (Compsemys),  233 
virginiana  (Amyda),  511,  515 
virginianus  (Trionyx),  515 
visendus  (Plastomenus),  467,  476 
vorax  (Aspideretes),  486,  496 
vyomingensis  (Adocus),  271 

(Dermatemys),  271 

(Emys),  308 
Wasatch  epoch,  turtles  of,  37 
wielandi  (Lytoloma),  157 
Writers  on  fossil  turtles,  i 
wyomingensis  (Baptemys),  270 

(Chrysemys),  308 

(Dermatemys),  271 

(Echmatemys),  298,  308 

(Emys),  308,  313,  316,  337 
Xenochclys,  224,  225,  226,  282 

formosa,  282 
Xerobates  cyclopygius,  438 

orthopygius,  438 

undata,  449 
Zygoramma,  225,  226,  257 

microglypha,  259 

striatula,  257 


LIST   OF   PLATES 


Plate  i. 
figures  from  drawings  furnished  by  u.   s.  geol.   survey. 

1.  Colpochelys  kern  pi.     Skull,  upper  aspect.     X  ^.     U.  S.  N.  M. 

2.  Colpochelys  kempi.     Same  skull,  lower  aspect.     X  ^. 

3.  Colpochelys  kempi.     Lower  jaw  of  same  skull,  seen  from  above.     X  y^. 

4.  Colpochelys  kempi.     Same  lower  jaw,  seen  from  side.     X  ^. 

5.  Platypeltis  ferox.     Lower  jaw,  lateral  view.     X  Yj.     U.  S.  N.  M. 

Plate  2. 
figures  from  drawings  furnished  by  u.  s.  geol.  survey. 

1.  Colpochelys  kempi.  Skull,  left  side.     X  Yz.     Same  specimen  as  Figs,  i  to  4,  PI.  i. 

2.  Colpochelys  kempi.  Left  scapula  and  coracoid.     X  y^.    Yale  Univ.  coll.  No.  638. 

3.  Colpochelys  kempi.  Left  humerus,  dorsal  aspect.     X  ^. 

4.  Colpochelys  kempi.  Same  humerus,  ventral  aspect.     X  y^. 

5.  Colpochelys  kempi.  Left  femur,  dorsal  aspect.     X  y^. 

6.  Colpochelys  kempi.  Same  femur,  ventral  aspect.     X  y^. 

Plate  3. 
figures  from   drawings  furnished  by   u.   s.  geol.   survey. 

1.  Platypeltis  ferox.     Skull,  upper  view.     X  y^.    U.  S.  N.  M. 

2.  Platypeltis  ferox.     Same  skull,  lower  view.     X  54. 

Z.  Platypeltis  ferox.    Left  scapula  and  coracoid.     X  5^.     cor,  coracoid;   pcor,  procoracoid 
process ;  scap,  scapula. 

4.  Platypeltis  ferox.    Left  humerus,  dorsal  view.     X  %. 

5.  Platypeltis  ferox.     Same  humerus,  ventral  view.     X  %. 

6.  Platypeltis  ferox.     Left  femur  of  same  individual,  dorsal  aspect.     X  y^. 

7.  Platypeltis  ferox.     Same  femur,  ventral  aspect.     X  J^. 

Plate  4. 
figures  from  drawings  furnished  by  u.  s.  geol.  survey. 

1.  Podocnemis  expansa.     Skull,  seen  from  above.     X  54.     U.  S.  N.  M. 

2.  Podocnemis  expansa.     Same  skull,  from  below.     X  0.5. 

3.  Podocnemis  expansa.    Lower  jaw  of  same  individual.    X  J^.    any,  angular;  art,  articular; 

dart,  dermarticular,  or  prearticular ;   dent,  dentary ;   spl,  splenial. 

4.  Podocnemis  expansa.     Lower  jaw  of  same  specimen   from  left  side.     X  0.5.     sur,  sur- 

angular. 

5.  Podocnemis  expansa.     Skull  seen  from  side.     X  0.5.     Same  individual  as  that  of  Fig.  i. 

Plate  5. 

1.  Glyptops  plicatulus.  Costal;  part  of  type.     X  i.     No.  6099  A.  M.  N.  H. 

2.  Glyptops  plicatulus.  Skull  viewed  from  side     X  i.     Yale  Univ.  coll.  No.  1357. 

3.  Glyptops  plicatulus.  Skull,  upper  aspect.     X  i.     No.  336  A.  M.  N.  H. 

4.  Glyptops  plicatulus.  Same  skull,  lower  aspect.     X  i. 

5.  Glyptops  plicatulus.  Plastron.     X  0.25.     Yale  Univ.  coll.  No.   165.     Drawing  from  U.  S. 

Geol.   Survey. 

Plate  6. 
Glyptops  plicatulus.     Carapace,  skull  and  neck.     X  0.5.     No.  336  A.  M.  N.  H. 

Plate  7. 

1.  Glyptops  ccelatus.    First  costal,  first  and  second  peripherals.     X  i.     No.  1930  U.  S.  N.  M. 

2.  Glyptops  cwlatus.     Fragment  of  costal.     X  i.     No.  1930  U.  S.  N.  M. 

3.  Glyptops?  belvidcrensis.     Neural,  lower  surface.     X  i.     Type  in  Colorado  College  coll. 

4.  Glyptops  belvidcrensis.     Distal  part  of  costal  of  type.     X  i. 

5.  Probaena  sculpta.     Plastron  of  type.     X  i.     In  Carnegie  Mus. 

557 


558 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


Plate  8. 


1.  Bacna  callosa.     Plastron  of  type.     X  o.6.     No.  330  Carnegie  Mus. 

2.  Baena  marshi.     Plastron  of  type.     X  0.47.     Yale  Univ.  coll. 

Plate  9. 

Baena  hatchcri.     Carapace  of  type.     X  4/g.     In  Carnegie  Mus.     (On  the  plate  the  size 
is   wrongly   given   as  4/7.) 

Plate  id. 

Baena  hatchcri.     Plastron  of  type.     X  0.4.     In   Carnegie  Mus.     (On   the  plate  the  size 
is  wrongly  given  as  J^.) 

Plate  ii. 

1.  Baena  escavada.     Carapace  of  type.     X  Y^.     No.  1203  A.  M.  N.  H. 

2.  Baena  escavada.     Plastron  of  type.     X  Yi. 

Plate  12. 
I.  Bu'cna  arcnosa.     Carapace.     X  0.5.     No.  5973  A.  M.  N.  H. 

Plate  13. 

1.  Bacna  arcnosa.     Plastron  of  type.     X  0.55.     No.  5973  A.  M.  N.  H. 

2.  Bacna  siina.     Skull,  upper  view.     X  i.     No.  5971  A.  M.  N.  H. 

3.  Bacna  sima.     Same  skull,  lower  view.     X  i. 

Plate  14. 

1.  Bacna  arcnosa.     Part  of  skull,  upper  side.     X  i.     No.  5973  A.  M.  N.  H. 

2.  Bacna  arcnosa.     Same  skull,  right  side.     X  i. 

3.  Bacna  arcnosa.     Same  skull,  lower  side.     X  i. 

4.  Bacna  sinia.     Skull  of  type,  from  right  side.     X  i.     No.  5971  A.  M.  N.  H. 

5.  Bacna  sima.     Lower  jaw  of  same  individual,  from  above.     X  I. 

6.  Baena  sima.     Same  jaw,  left  side.     X  i. 

Plate  15. 
Bai:na  sima.     Carapace  of  paratype.     X  0.5.     No.  5965  A.  M.  N.  H. 

Plate  16. 

1.  Bacna  clara.     Carapace  of  type.     X  0.4.     No.  6075  A.  M.  N.  H. 

2.  Bacna  clara.     Plastron  of  type.     X  0.4. 

Plate  17. 
Bacna  riparia.     Skeleton  of  type  viewed  from  above.     X  0.4.     No.  5977  A.  M.  N.  H. 

Plate  18. 

Bacna  riparia.     Skeleton    viewed    from    below,    with    part   of    plastron    removed.     X  0.4. 
No.  5977  A.  M.  N.  H. 

Plate  19. 

1.  Bai;na  riparia.     Skull  of  type,  upper  side.     X  i.     No.  5977  A.  M.  N.  H.  ' 

2.  Bacna  riparia.     Same  skull,  lower  side.     X  i. 

3.  Bacna  riparia.     Lower  jaw  of  same  skull.     X  i. 

4.  Euhacna  ccphatica.     Skull  forming  type.     X  i.     No.  31 10  Yale  Univ.  coll. 

5.  Tcstudo  z-aga.     Part  of  carapace,     X  0.5.     No.  1326  A.  M.  N.  H. 

6.  Tcstudo  orthopygia.     Plastron  of  cotype  of  Xcrobatcs  cyclopygia.     Cope.    X  0.2.    No.  1323 

A.  M.  N.  H. 

7.  Tcstudo  orthopygia.     Carapace   of  cotype  of   Xcrobatcs  cyclopygia.       X  0.2,      No.    1323 

A.  M.  N.  H. 


INDEX   OF   PLATES.  rCQ 

Plate  20. 

1.  Baena  eviilia.     Carapace  of  type.     X  0.4.     No.  1925  A.  M.  N.  H. 

2.  Baena  emilice.     Plastron  of  type.     X  0.4. 

Plate  21. 

1.  Eubaena  cephalica.     Skull   forming  type,  upper  aspect.     X  i.     No.  21 10  Yale  Univ.  coll. 

2.  Eubaena  cephalica.     Same  skull,  lower  aspect.     X  i. 

3.  Chistcrnon  hcbraicum.     Skull,  upper  aspect.     X  i.     No.  5561  A.  M.  N.  H. 

4.  Chisternon  hebraicurn.     Same  skull,  lower  aspect.     X  i. 

Plate  22. 
Chisternon  undatum.     Carapace.     X  0.34.     No.  3932  A.  M.  N.  H. 

Plate  23. 

1.  Chisternon  hcbraicum.     Skull,  right  side.     X  i.     No.  5961  A.  M.  N.  H. 

2.  Bothrcmys  cooki.     Skull  of  type,  lower  surface.     X  0.8.     Type  in  Rutgers  College,  N.  j, 

3.  Bothrcmys  cooki.     Lower  jaw  of  type.     X  0.8. 

4.  Osteopygis  chelydrinus.     Seventh  peripheral  of  type.     X  0.75.     No.  1131  A.  M.  N.  II. 

5.  Osteopygis  chelydrinus.     Same  bone,  inner  surface.     X  0.75. 

6.  Osteopygis  chelydrinus.     Second  left  peripheral  of  type,  outer  surface.     X  0.75. 

7.  Osteopygis  chelydrinus.     Same  peripheral,  inner  surface,     x  0.75. 

Plate  24. 
Thescelus  insiliens.    Carapace  of  type.     X  Yi.     No.  1108  A.  M.  N.  H. 

Plate  25. 
Thescelus  insiliens.     Plastron  of  type.     y~  Yj.     No.  1108  A.  M.  N.  H. 

Plate  26. 

1.  Osteopygis  gibbi.     Rim  of  carapace  of  type,  seen   from  below.     X  0.23.     Type  in  Yale. 

Drawing  furnished  by  U.  S.  Gcol.  Surv. 

2.  Osteopygis  erosus.     Sixth  to  tenth  peripherals.     X  0.27.     No.  1130  A.  M.  N.  H. 

3.  Osteopygis  borealis.     Seventh  to  eleventh  peripherals.     X  0.27.     No.  1132  A.  M.  N.  H. 

Plate  27. 

1.  Osteopygis  gibbi.     Carapace  of  type.     X  %  +.     Type  in  Yale  Univ.  coll. 

2.  Osteopygis  gibbi.     Plastron  of  type.     X  %-{-. 

Plate  28. 

1.  Osteopygis  chelydrinus.    Third    peripheral    of    type,    outer    surface.      X  0.75.      No.  113: 

A.  M.  N.  H. 

2.  Osteopygis  chelydrinus.     Same  peripheral,  inner  surface.     X  0.75. 

3.  Osteopygis  chelydrinus.     Lower  jaw,  upper  surface.     X  0.75.     Part  of  type. 

4.  Osteopygis  chelydrinus.     Same  jaw,  right  side.     X  0.75. 

5.  Lytoloma  angusta.     Lower  jaw  accompanying  type  peripheral.   X  0.6.  No.  1133  A.  M.  N.  H. 

6.  Lytoloma  angusta.     Peripheral  forming  type.     X  0.6.     No.  1133  A.  M.  N.  H. 

7.  Lytoloma  wielandi.    Upper  surface  of  frortt  of  skull,  forming  type.     X  0.8.     Yale  Lfniv. 

coll.     Drawing  from  U.  S.  Geol.  Surv. 

8.  Lytoloma  wielandi.     Same  specimen,  lower  surface.     X  0.8. 

Plate  29. 

1.  Lytoloma  wielandi.     Type  fragment  of  skull,  seen  from  behind.     X  0.8. 

2.  Rhetechelys  platyops.     Skull    forming  type,   upper   surface.     X  0.4.     Type   in  coll.    Phila. 

Acad. 

3.  Rhetechelys  platyops.     Same  skull,  inferior  surface.     X  0.4. 


560  FOSSIL    TURTLES    OF    NORTH    AMERICA. 

Plate  30. 

1.  Toxochelys  sp.  indet.     Neurals  2  to  8,  suprapygal,  pygal  and  peripherals.     X  0.6.     Speci- 

men in  coll.  Kansas  Univ. 

2.  Toxochelys  sp.  indet.     Neurals  and  suprapygal  of  same  specimen,  lateral  view.     X  0.6. 

Plate  31. 

1.  Toxochelys  brachyrhina.     Skull  forming  type,  lower  surface.    X  0.5.    Type  in  coll.  Kansas 

Univ. 

2.  Porthochelys  laticeps.    Carapace  of  type.     X  %.    Type  in  coll.  Kansas  Univ. 

3.  Porthochelys  laticeps.     Plastron  of  type.     X  %. 

Plate  32. 

1.  Syllomus  crispatus.     Distal  half  of  costal  of  type.     X  0.8.     No.  6134  A.  M.  N.  H. 

2.  Syllomus  crispatus.     Part  of  costal  of  type.     X  0.8. 

3.  Chelonia  parmtecta.     Costal  forming  type.     X  0.6.     No.  1318  A.  M.  N.  H.     (On  plate  the 

size  is  wrongly  given  as  5^.) 

4.  Basilemys  variolosa.     Front  of  plastron.     X  Y^.    From  photograph  by  Lambe.     Specimen 

in  coll.  Geol.  Surv.  Canada. 

5.  Basilemys  imbricaria.    Fragment  of  costal  of  type.  X  i.     No.  6102  A.  M.  N.  H. 

6.  Basilemys  imbricaria.    Fragment  of  costal  of  type.  X  i. 

7.  Basilemys  imbricaria.    Fragment  of  costal  of  type.  X  i. 

Plate  33. 

1.  Basilemys  sinuosa.    Carapace  of  type.     X  0.2.     From  photograph  furnished  by  Field  Mus. 

Nat.  Hist. 

2.  Basilemys  sinuosa.     Plastron  of  type.     X  0.2. 

Plate  34. 

1.  Basilemys  variolosa.     Part  of  seventh  peripheral  of  type,  to  show  sculpture.     X  i.     No. 

1465  A.  M.  N.  H. 

2.  Compsemys  victa.    Fragment  of  costal,  to  show  sculpture.     X  i. 

3.  Compsemys  victa.     Right  eighth  costal.     X  i.     No.  6096  A.  M.  N.  H. 

4.  Compsemys  obscura.     Supposed  second  left  costal.     X  i.     Specimen  in  A.  M.  N.  H. 

5.  Adocus  punctatus.    Upper  surface  of   xiphiplastron  of  type.     X  0.25.     Yale  Univ.   coll. 

6.  Adocus  beatus.     Plastron.     X  0.25.     Coll.  A.  M.  N.  H. 

7.  Adocus  beatus.    First  right  peripheral  of  same  specimen.     X  0.5. 

8.  Adocus  lacer.     Nuchal,  3  peripherals  and  part  of  costal.     X  0.25.     No.  1350  A.  M.  N.  H. 

Plate  35. 

1.  Adocus  punctatus.     Carapace  of  type.     X  0.25.     Yale  Univ.  coll. 

2.  Adocus  punctatus.     Plastron  of  type.     X  0.25. 

Plate  36. 

1.  Adocus  lacer.    Plastron  of  type.     X  0.25.    No.  1350  A.  M.  N.  H. 

2.  Adocus  syntheticus.     Plastron  of  type.     X  0.2.     No.  1466  A.  M.  N.  H. 

3.  Adocus  agilis.     Plastron  of  type.     X  0.2.     No.  1466  A.  M.  N.  H. 

4.  Adocus  petrosus.    Right  hypoplastron  and  two  peripherals.     X  0.5.     No.  1482  A.  M.  N.  H. 

Plate  37. 

1.  Agomphus  turgidus.  Portion  of  plastron  of  type.     X  0.5.     No.  1481  A.  M.  N.  H. 

2.  Agomphus  turgidus.  Both  hyoplastrals,  lower  surface.     X  0.5.     No.  1479  A.  M.  N.  H. 

3.  Agomphus  turgidus.  Same  bones  seen  from  in  front.     X  0.5. 

4.  Agomphus  turgidus.  Eighth,  ninth  and  tenth,  right  peripherals  of  type.     X  0.5. 

5.  Agomphus  turgidus.  Fourth  neural  and  proximal  ends  of  four  costals  of  type.     X  0.5. 

6.  Agomphus  petrosus.  Two   peripherals   and   part   of   costal   of   type.      X  0.5.     No.    1482 

A.  M.  N.  H. 

7.  Agomphus  petrosus.    Fourth  and  fifth  right  costals  of  type.     X  0.5. 


INDEX   OF   PLATES.  r^I 

8.  Agomphus  pecloralis.    Both  hyoplastra  of  type,  lower  surface.     X  0.5. 

9.  Agompfvus  pectoralis.     Same  bones  seen  from  in  front.     X  0.5. 

ID.  Zygoramma  striatula.     Inner  surface  of  a  bridge  peripheral  of  type,  showing  end  of  rib. 
X  0.4.     In  A.  M.  N.  H. 

11.  Baptemys  wyomingensis.     Skull    seen    from   above.     X  0.75.     No.  484  Yale  Univ.  coll. 

12.  Baptemys  uyotningensis.     Same  skull  seen  from  below.     X  0.75. 

13.  Baptemys  ivyomingensis.     Same  skull  seen  from  side.     X  0.75. 

Plate  38. 

1.  Zygoramma  striatula.     Both  hypoplastra  of  type.     X  0.5.     In  A.  M.  N.  H. 

2.  Zygoramma  striatula.     Three  peripherals  and  part  of  costal  of  type.     X  0.5. 

3.  Zygoramma  striatula.     Same  bones,  inner  surface.     X  0.5. 

4.  Hoplochelys  crassa.     Sixth    right    peripheral    of    type,    outer    surface.     X  i.     No.  6091 

A.  M.  N.  H. 

5.  Hoplochelys  crassa.     Same  bone,  inner  surface.     X  i. 

6.  Hoplochelys  crassa.    Fourth  or  fifth  peripheral  of  type,  outer  surface.     X  i. 

7.  Hoplochelys  crassa.     Same  bone,  inner  surface.     X  i. 

8.  Hoplochelys  crassa.     Proximal  ends  of  two  costals  of  type,  showing  lateral  carina. 

9.  Hoplochelys  crassa.     Pygal  of  type.     X  i. 

ID.  Baptemys  wyomingensis.     Skull    seen   from   above.     X  i.     No.  5967  A.  M.  N.  H. 

Plate  39. 

1.  Alamosemys  substricta.     Carapace  of   type.     X  0.25.     No.  1204  A.  M.  N.  H. 

2.  Alamosemys  substricta.     Plastron  of  type.     X  0.25. 

Plate  40. 

1.  Baptemys  wyomingensis.    Carapace.     X  J^.    No.  1494  A.  M.  N.  H. 

2.  Naomichelys  speciosa.     Entoplastron    forming    type,    outer    surface.     X  0.75.     No.    6136 

A.  M.  N.  H. 

3.  Naomichelys  speciosa.     Same  bone,  inner  surface.     X  0.75. 

Plate  41. 

1.  Baptemys  wyomingensis.     Carapace.     X  0.28.     No.  5967  A.  M.  N.  H. 

2.  Baptemys  wyomingensis.     Plastron  of  same  specimen.     X  0.28. 

Plate  42. 

1.  Baptemys  fluviatilis.    Carapace  of  type.     X  0.24.     Geol.  Dept.  A.  M.  N.  H. 

2.  Baptemys  fluviatilis.     Plastron  of  type.     X  0.24. 

Plate  43. 

1.  Anosteira  omata.    Carapace.     X  i.    No.  6132  A.  M.  N.  H. 

2.  Anosteira  omata.    Plastron.     X  i. 

Plate  44. 

1.  Gyremys  spectabilis.     Carapace  of  type.     X  0.25.     No.  1171  A.  M.  N.  H. 

2.  Gyremys  spectabilis.     Plastron  of  type.     X  0,25. 

Plate  45. 

1.  Clemmys  morrisice.    Anterior  lobe  of  plastron  of  type,  upper  surface.     X  0.8.     No.  6029 

A.  M.  N.  H. 

2.  Clemmys  morrisice.     Part  of  right  side  of  hinder  lobe  of  plastron,  upper  surface.     X  0.8. 

No.  6029  A.  M.  N.  H. 

3.  Clemmys  morrisice.    Upper   surface  of   left   xiphiplastron.     X  0.8.     No.  6025  A.  M.  N.  H. 

4.  Clemmys  hesperia.     Left  hyoplastron.     Type.     X  i.     No.  2219  Univ.  Cal.  coll. 

5.  Clemmys  hesperia.    Right  epiplastron.     X  i.     No.  2179  Univ.  Cal.  coll. 

6.  Clemmys  hesperia.     First  right  peripheral.     X  i.     No.  2179  Univ.  Cal.  coll. 

7.  Clemmys  hesperia.     Ninth  left  peripheral.     X  i.     No.  552  Univ.  Cal.  coll. 


56. 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


8.  Clemmys  saxea.     Pygal  of  type.     X  i.     No.  2192  Univ.  Cal.  coll. 

9.  Clemmys  saxca.     Same  bone,  inner  surface.     X  i. 

10.  Clemmys  saxea.     Tenth  left  peripheral  of  type.     X  i. 

11.  Echmatcmys  sp.  indet.     Skull,  upper  view.     X  i.     Princeton  Univ.  coll. 

12.  Echmatemys  sp.  indet.     Same  skull,  lower  view.     X  i. 

13.  Echmatcmys  sp.  indet.     Same  skull,  right  side.     X  i. 

14.  Echmatemys  mcgaulax.     Neural  bone.     X  i.     No.  1184  A.  M.  N.  H. 

15.  Echmatemys  megaulax.     Peripheral  bone.     X  i.     No.  1184  A.  M.  N.  H. 

16.  Echmatcmys  testudinea.    Third  and  fourth  right  peripherals.   X  0.8.  No.  1178  A.  M.  N.  H. 

17.  Echmatemys  testudinea.     Sixth   costal.     X  0.8.     No.  1179  A.  M.  N.  H. 

Plate  46. 

1.  Echmatemys  euthneta.     Part  of  plastron.     X  0.96.     No.  1176  A.  M.  N.  H. 

2.  Chryscmys  timida.      Carapace   of    type.      X  0.62    of    natural    size.      No.  10853    Princeton 

Univ.  coll. 

3.  Trachemys  petrolei.    Two  epiplastra  of  different  individuals.     X  0.8.     Cotypes.     No.  3933 

A.  M.  N.  H. 

4.  Trachemys  petrolei.     Nuchal  bone  accompanying  cotypes.     X  08..     No.  3933  A.  M.  N.  H. 

Plate  47. 

1.  Echmatemys  zvyomingensis.     Plastron  viewed   from  above.     X  0.4.     A.  M.  N.  H. 

2.  Echmatemys  haydeni.     Plastron  viewed   from   above.     X  0.4.     A.  M.  N.  H. 

Plate  48. 

1.  Echmatemys  stevensoniana.     Carapace  of  type.     X  0.4.     No.  6084  A.  M.  N.  H. 

2.  Echmatemys  stevensoniana.     Plastron  of  same  specimen.     X  0.4. 

Plate  49. 

1.  Echmatemys  arethusa.     Carapace  of  type.     X  0.5.     No.  5920  A.  M.  N.  H. 

2.  Echmatemys  arethusa.     Plastron  of  type.     X  0.5. 

Plate  50. 

1.  Echmatemys  shaughnessiana.     Carapace  of  type.     X  0.375.     No.  io6g  A.  M.  N.  H. 

2.  Echmatemys  shaughnessiana.     Plastron  of  type.     X  0.375. 

Plate  51. 

1.  Echmatemys  naomi.     Carapace  of  type.     X  J^.     No.  5975  A.  M.  N.  H. 

2.  Echmatemys  naomi.     Plastron  of  type.     X  J^. 

Plate  52. 

1.  Echmatemys  callopygc.     Carapace  of  type.     X  0.3.     No.  2087  A.  M.  N.  H. 

2.  Echmatemys  callopygc.     Plastron  of  type.     X  0.3. 

Plate  53. 

1.  Echmatemys  uintensis.    Carapace  of  type.     X  0.3.     No.  11 198  Princeton  Univ.  coll. 

2.  Echmatemys  uintensis.     Plastron  of  type.     X  0.3. 

Plate  54. 

1.  Deirochelys  fioridana.     Nuchal  forming  type.     X  0.8.     In  coll.  Vandcrbilt  Univ. 

2.  Deirochelys  fioridana  f    First  costal.     X  0.8.     In  Vanderbilt  Univ. 

3.  Trachemys  euglypha?    Nuchal.     X  0.8.     In  Wagner  Free  Inst. 

4.  Trachemys  sculpta.     Nuchal  forming  type.     X  0.8.     In  coll.  Vanderbilt  Univ. 

5.  Trachemys  sculpta.    Third?  costal.     X  0.8.     In  coll.  Vanderbilt  Univ. 
6  and  7.  Trachemys  sculpta?    Neural  bone.     X  0.8.     Same  coll. 

8.  Trachemys  sculpta?    Costal  bone.     X  0.8.     Same  coll. 

9.  Trachemys  sculpta?    Costal  bone.     X  0.8.     Same  coll. 

10.  Trachemys?  jarmani.    Nuchal  forming  type.     X  08.     In  coll.  Vanderbilt  Univ. 

11.  Trachemys?  jarmani?    Right   eighth   peripheral.     X  0.8.     Same   coll. 

12.  Trachemys?  jarmani?    Proximal  end  of  costal.     X  0.8.     Same  coll. 

13.  Pseudemys  extincta.     Nuchal  forming  type.     X  0.8.     Same  coll. 


INDEX   OF   PLATES. 

Plate  55. 
Trachemys  hilli.    Carapace  of  type.     X  0.7.     No.  2425  A.  M.  N.  H. 


563 


Plate  56. 

1.  Trachemys  bisornata.     Part  of  carapace.     X  0.8.     Specimen  in  coll.  Phila.  Acad. 

2.  Trachemys  trulla.     Part  of  epiplastra,  lower  surface.    X  0.8.    Type,  No.  3934  A.  M.  N.  H. 
Same  bones,  upper  surface.     X  0.8. 
Right  hyoplastron  of  type.     X  0.8. 
Right  hypoplastron  of  type.     X  0.8. 
Left   .xiphiplattron  of   type.     X  0.8. 

Left  hyoplastron  forming  type.     X  ^.     In  A.  M.  N.  H. 


3.  Trachemys  trulla. 

4.  Trachemys  trulla. 

5.  Trachemys  trulla. 

6.  Trachemys  trulla. 

7.  Terrapene  putnami. 


8.  Terrapene  putnami.     Same  bone  showing  lateral  hinge.     X  Yi. 


1.  Pseudemys  ccelata. 

2.  Pseudemys  ccelata. 

3.  Pseudemys  ccelata. 

4.  Pseudemys  ccelata. 

5.  Pseudemys  ccelata. 

6.  Pseudemys  ccelata. 


Plate  57. 

Nuchal. 

Fifth  left  costal. 

Left  third  peripheral. 

Left  tenth  peripheral. 

Left  hypoplastron. 

Left  first  costal  of  smaller  individual. 


AH  figures  slightly  less  than  natural  size.     From  type,  No.  2508  U.  S.  N.  M. 


1.  Terrapene  marnochi. 

2.  Terrapene  marnochi. 


Plate  58. 

Carapace,  side  view.     X  0.625. 
Same  carapace,  upper  view. 


No.  3936  A.  M.N.  H. 


Plate  59. 

1.  Hadrianus  majusculus.  Shell  of  the  type.     X  0.25.     In  Yale  Univ.  coll. 

2.  Stylcmys  ncbrasccnsis.  Skull,  upper  side.     X  i.     Princeton  Univ.  coll. 

3.  Stylemys  ncbrasccnsis.  Same  skull,  lower  side.     X  i. 

4.  Stylemys  ncbrasccnsis.  Egg.     X  i.     A.  M.  N.  H. 

Plate  60. 
Hadrianus  corsoni.     Carapace.     X  0.375.     No.  6027  A.  M.  N.  H. 

Plate  61. 
Hadrianus  corsoni.     Plastron.     X  0.375.     No.  6027  A.  M.  N.  H. 

Plate  62. 

1.  Stylemys  ncbrasccnsis.     Carapace.     X  0.5.     No.  1433  A.  M.  N.  H. 

2.  Stylemys  ncbrasccnsis.     Plastron  of  same  shell.     X  0.5. 

Plate  63. 

1.  Stylemys  capax.     Carapace  of  type.     X  0.28.     No.  1357  A.  M.  N.  H. 

2.  Stylemys  capax.     Plastron  of  type.     X  0.28. 

Plate  64. 
I.  Stylemys  conspccta.     Carapace  of  type.     X  0.45.     No.  1358  A.  M.  N.  H. 

Plate  65. 

1.  Tcstudo  brontops.     Carapace  of  type.     X  0.15.     In  Yale  Univ.  coll. 

2.  Tcstudo  brontops.     Plastron  of  type.     X  0.15. 

Plate  66. 

1.  Testudo  thomsoni.     Front  of  plastron  of  type.     X  0.5.     No.  3940  A.  M.  N.  H. 

2.  Testudo  thomsoni.     Skull  of  type,  upper  side.     X  0.8. 


564 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


3.  Tcstudo  thomsoni.     Skull  of  type,  lower  side.     X  0.8. 

4.  Tcstudo  thomsoni.     Skull  of  type,  left  side.     X  0.8. 

5.  Tcstudo  thomsoni.    Lower  jaw  of  type,  left  ramus.     X  0.8. 

6.  Tcstudo  exornata.     Distal  end  of  left   fifth   costal  of   type.      X  0.8.     Specimen   in   coll. 

Geol.  Surv.  Canada. 

7.  Tcstudo  exornata.     Same  costal,  inner  surface.     X  0.8. 

Plate  67. 

1.  Tcstudo  laticunca.     Carapace  of  type.     X  0.28.     No.  1148  A.  M.  N.  H. 

2.  Tcstudo  laticunca.     Plastron  of  type.     X  0.28. 

Plate  68. 
from  photographs  furnished  by  carnegie  mus.,  pittsburg. 

1.  Tcstudo  inusitata.     Carapace  of  type.     X  0.5,     No.  311  Carnegie  Mus. 

2.  Tcstudo  inusitata.     Plastron  of  type.     X  0.5. 

Plate  69. 
from  photographs  furnished  by  dr.  w.  b.  scott. 

1.  Tcstudo  farri.     Carapace  of  type.     X  0.375.     No.  10486  Princeton  Univ.  coll. 

2.  Tcstudo  farri    Plastron  of  type.     X  0.375. 

Plate  70. 

1.  Tcstudo  cmilicB.     Carapace  of  type.     X  0.4.     No.  6x35  A.  M.  N.  H. 

2.  Tcstudo  emilia.     Plastron  of  type.     X  0.4. 

Plate  71. 

1.  Tcstudo  pansa.     Carapace  of  type.     X  1/7.     No.  5869  A.  M.  N.  H. 

2.  Tcstudo  pansa.     Plastron  of  type.     X  1/7. 

Plate  72. 
Tcstudo  osborniana.     Carapace  of  type.     X  0.2.     No.  5868  A.  M.  N.  H. 

Plate  73. 
Tcstudo  osborniana.     Plastron  of  type.     X  0.2.     No.  5868  A.  M.  N.  H. 

Plate  74. 

Tcstudo  osborniana.     Carapace,  limbs,  head,  neck  and  internal  skeleton.    X  0.2.    No.  5870 

A.  M.  N.  H. 

Plate  75. 

J.  Tcstudo  osborniana.     Carapace.     X  0.4.     No.  5871  A.  M.  N.  H. 
2.  Tcstudo  osborniana.     Plastron.     X  04. 

Plate  76. 

Tcstudo  impcnsa.    Carapace  of  type.     X  J^.     No.  5867  A.  M.  N.  H.     The  central  portions 
are  crushed  inwards  and  d  sturbed. 

Plate  77. 
Tcstudo  impcnsa.     Plastron  of   type.     X  %.     No.  5867  A.  M.  N.  H. 

Plate  78. 

1.  Tcstudo  orthopygia.     Plastron  of  type.     X  0.25.     No.  3929  A.  M.  N.  H. 

2.  Tcstudo  orthopygia.     Rear  of  shell.     X  %.     No.  1325  A.  M.  N.  H, 


INDEX   OF   PLATES.  ^65 

Plate  79. 

1.  Testudo  orthopygia.    Carapace.     X  0.4.     Mostly  from  No.  2415,  but  partly  from  Nos.  3931 

and  2320  A.  M.  N.  H.    Represents  young  individuals  called  by  Cope  Xerobatcs 
cyclopygia. 

2.  Testudo  orthopygia.     Plastron.     X  0.4.     Mostly  from  No.  2415,  but  partly  from  No.  3931 

A.  M.  N.  H.     Form  called  by  Cope  Xerobatcs  cyclopygia. 

Plate  80. 

1.  Testudo  orthopygia.     Shell,  side  view.     X  0.4.     Restored  from  same  specimens  as  figures 

of  Plate  79. 

2.  Testudo  gilberti.     Skull  of  type,  seen  from  above.    X  0.75.  From  type  in  coll.  Univ.  Kansas. 

3.  Testudo  gilberti.     Same  skull  seen  from  below.     X  0.75. 

4.  Testudo  gilberti.     Same  skull,  right  side.     X  0.75. 

5.  Testudo  gilberti.     Lower  jaw  of  same  skull.     X  0.75. 

Plate  8i. 
Testudo  orthopygia.    Carapace.     X  0.25.     No.  6108  A.  M.  N.  H.  , 

Plate  82. 
Testudo  orthopygia.     Plastron.     X  0.25.     No.  6108  A.  M.  N.  H. 

Plate  83. 

FROM    photographs    FURNISHED    BY    CARNEGIE    MUS.,    PITTSBURG. 

1.  Testudo  edcB.     Carapace  of  type.     X  0.3.     No.  1535  Carnegie  Mus. 

2.  Testudo  edce.     Plastron  of  type.     X  0.3. 

Plate  84. 

FROM    photographs    FURNISHED   BY    CARNEGIE    MUS.,    PITTSBURG. 

1.  Testudo  hollandi.     Carapace  of  type.     X  Yi.     N0.IS61  Carnegie  Mus. 

2.  Testudo  hollandi.     Plastron  of  type.     X  >^. 

Plate  85. 

1.  Plastomenus  costatus.     Costal  bone.     Slightly  reduced.     No.  6131  A.  M.  N.  H. 

2.  Plastomenus  costatus.     Right    xiphiplastron.     Slightly    reduced.     No.  6131  A.  M.  N.  l\. 

3.  Plastomenus  molopinus.     Carapace.     X  0.6.     No.  5941  .\.  M.  N.  H. 

Plate  86. 
reproduction  of  figures  by  cope. 

1.  Plastomenus  catenatus.    Fragment  of  costal.     X  i.     No.  1138  U.  S.  N.  M. 

2.  Plastomenus?  lepiomitus.     Fragment  of  costal.     X  i.     No.  1113U.  S.  N.  M. 

3.  Plastomenus?  lachrymalis.     Fragment  of  costal.     X  i.     a,  view  of  edge  of  fragment. 

4.  Plastomenus?  fractus.    Fragments    of    costals.     X  i.     Types    lost,    w,   x,   the   proximal 

end  of  a  costal,  showing  both  surfaces;  y,  z,  fragments  of  two  costals. 

5.  Plastomenus  corrugatus.     Part  of  left  hypoplastron.     X  i.     Original  lost. 

6.  Plastomenus  communis.    Two  peripherals.     X  i.     (7,  seen  from  above;  b,  view  of  edge. 

Type.     No.  1132U.  S.  N.  M. 

7.  Plastomenus  communis.     Two  peripherals  of  type.     X  i. 

8.  Plastomenus  communis.     Fragment  of  hyoplastron  of  type.     X  i. 
g.  Amyda  cariosa.     Neural.     X  i.     Type.     No.  2575  U.  S.  N.  M. 

10.  Amyda  cariosa.    Fragment  of  costal  of  type.     X  i. 

11.  Amyda  radula.     Fragment  of  costal  of  type.     X  i.     No.  2581  U.  S.  N.  M. 

12.  Amyda  radula.    Fragment  of  costal  of  type.     X  i. 

Plate  87. 

1.  Plastomenus  visendus.     Carapace.     X  0.5.     Type.     No.  1895  A.  M.  N.  H. 

2.  Plastomenus  visendus.     Plastron  of  same  specimen.     X  0.5. 


566 


FOSSIL    TURTLES    OF    NORTH    AMERICA. 


Plate  88. 


1.  Conchochclys  admirabilis.     Skull  of  type,  view  from  above.     X  Yj.     No.  6090  A.  M.  N.  H. 

2.  Conchochelys  admirabilis.     Same  skull,  seen  from  below.     X  y^. 

3.  Conchochelys  admirabilis.     Same  skull,  seen  from  right  side.     X  y^. 

4.  Hclopanoplia  distincta.     Fragment  of  costal  type.     X  i.     U.  S.  N.  M. 

5.  Helopdiwplia  distincta.     Portion  of  plastral  bone  of  type.     X  i.     U.  S.  N.  M. 

6.  Aspidcretes  coalesccns.     Fragment  of  costal.     X  i.     Shows  the  sculpture.     From  photo- 

graph furnished  by  L.  M.  Lambe. 

7.  Aspidcrctes  splendidus.     Portion  of  distal  third  of  second  costal  of  type.     X  i.     No.  3952 

A.  M.  N.  H.     Shows  character  of  sculpture. 

8.  Aspideretes  splendidus.     Portion  of  distal  end  of  fourth  costal  of  type.     X  i. 

9.  Aspidcrctes  splendidus.     Portion  of  proximal  half  of  third  costal.     X  i. 

Plate  89. 

1.  Aspidcrctes  foi'eatus.     Carapace.     X  0.5.     From  photograph  by  L.  M.  Lambe.     Specimen 

in  coll.  Geol.  Surv.  Canada. 

2.  Aspidcrctes  foveatus.     Right  hypoplastron.    X  i.    From  drawing  by  L.  M.  Lambe.    Speci- 

men in  coll.  Geol.  Surv.  Canada. 

Plate  90. 

1.  Aspidcrctes  coalesccns.     Carapace.     X  0.25.     From  photograph  by  L.  M.  Lambe.     Speci- 

men in  coll.  Geol.  Surv.  Canada. 

2.  Aspidcrctes  bcechcri.     Carapace.     X  J^-     No.  2358  U.  S.  N.  M. 

Plate  91. 
Aspidcrctes  splendidus.     Carapace  of  type.     X  0.28.     No.  3952  A.  M.  N.  H. 

Plate  92. 

1.  Aspidcrctes  bcechcri.     Carapace  and  part  of  neck,  limbs  and  tail  of  type.     X  0.25.     Speci- 

men in  Yale  Univ.  coll.     Photograph  by  Wieland. 

2.  Aspidcrctes  bcechcri.     Plastron  of  type.     X  0.25.     Photograph  by  Wieland. 

Plate  93. 

1.  Aspidcrctes  sat/atus.     Carapace  of  type.     X  ]/}.     No.  1201  A.  M.  N,  H. 

2.  Aspideretes  sagatiis.     Portions  of  neurals  and  costals,  to  show  sculpture.    X  i.   From  type. 

3.  Aspidcrctes  sagatus.     Distal  portion  of  a  costal.     X  i.     From  type. 

Plate  94. 

1.  .Aspidcrctes  pucrccnsis.     Carapace  of  type.     X  0.5.     No.  1202  .A..  M.  N.  H. 

2.  Aspidcrctes  pucrccnsis.     Portion  of  first  costal  of  type,  taken  near  center.     X  i. 

3.  Aspideretes  pucrccnsis.     Portion  of  proximal  end  of  third  costal  of  type.     X  i. 

Plate  95. 

\.  .-ispideretcs  cllipticus.     Carapace  of  type.     X  0.4.     No.  1117  A.  M.  N.  H. 

2.  Aspideretes  cllipticus.     Portion  of   fifth   nevtral   and   of   fifth   and   sixth   costals  of  type. 

X  I.     To  show  character  of  sculpture. 

3.  Aspidcrctes  cllipticus.     Portion  toward  distal  end  of  fifth  costal  of  type.     X  i. 

Plate  96. 

1.  Aspidcrctes  bcechcri.     Portions  of  two  costals  of  type,  to  show  sculpture.     X  i. 

2.  Aspideretes  bcechcri.     Portion  of  costal  to  show  sculpture.     X  i.     No.  2358  U.  S.  N.  M. 

3.  Aspideretes  vagans.    Type  fragment  of  costal.     X  i.     No.  1847  A.  M.  N.  H. 

4.  Amyda?  halophila.     Neural  and  part  of  costal  of  type.     X  i.     No.  1476  A.  M.  N.  H. 

5.  Amydaf  halophila.    Fragment  of  costal.     X  i.    No.  1476  A.  M.  N.  H. 

6.  Amydaf  pennata.     Costal  forming  type.     X  I.     No.  1165  A.  M.  N.  H. 

7.  Amydaf  zirginiana.     Portion  of  costal  of  type.     X  i.     In  coll.  Maryland  Geol.  Surv. 

8.  Amyda?  virginiau'.t.     Second  portion  of  costal  of  type.     X  i.     In  coll.  Maryland  Geol.  Surv. 


INDEX   OF   PLATES. 


567 


3.  Amy  da  f  prise  a. 

4.  Amydaf  prisca. 

5.  Amydaf  prisca. 

6.  Amyda?  prisca. 


4.  Amyda  ventricosa. 

5.  Amyda  ventricosa. 

6.  Amyda  ventricosa. 

7.  Amyda  concentrica. 

8.  Amyda  concentrica. 

9.  Amyda  concentrica. 
Amyda  concentrica. 


Plate  97. 

1.  Aspideretes  grangeri.    Carapace  of  type.     X  0.4.     No.  3942  A.  M.  N.  H. 

2.  Amyda?  prisca.     Proximal  end  of  costal.     X  i.     No.  2401  A.  M.  N.  H. 
Distal  end  of  costal.     X  i.     No.  2401  A.  M.  N.  H. 
Supposed  part  of  nuchal.     X  i.     No.  2401  A.  M.  N.  H. 
Supposed     last  costal.     X  i.     No.  2401  A.  M.  N.  H. 
Portion  of  costal.     X  i.     No.  2401  A.  M.  N.  H. 

Plate  98. 

1.  Amyda  ventricosa.     Distal  end  left  hypoplastron  of  type.     X  i.     No.  1112  U.  S.  N.  M. 

2.  Amyda  ventricosa.     Distal  end  of  left  hypoplastron  of  another  individual.     X  i.     No.  11 12 

U.  S.  N.  M. 

3.  Amyda  ventricosa.  Undetermined  fragment  of  same  lot. 
Distal  end  of  costal  plate  of  same  lot. 
Portion  of  costal  of  small  individual  of  same  lot. 

Fragment  of  costal  of  same  lot. 

Fragment  of  costal  of  type.     X  i.     In  A.  M.  N.  H. 

Fragment  of  costal  of  type. 

Fragmetit  of  costal  of  type. 

10.  Amyda  concentrica.    Fragment  of  costal  of  type. 

11.  Amyda  lima.     Portion  of  costal  forming  type.     X  i.     In  A.M.  N.  H. 

12.  Amyda  buiei.    Fragment  of  costal.     X  i.     In  A.  M.  N.  H. 

13.  Platypeltis  serialis.     Left  half  of  carapace.     X  i.     No.  6014  A.  M.  N.  H. 

14.  Platypeltis  heteroglypta.     Part  of  middle  of  fifth  costal  of  type.     X  i.    No.  1039  A.  M.  N.  H. 

Plate  99. 

1.  Amyda  aqua.     Carapace  of  type.     X  0.31.     U.  S.  N.  M. 

2.  Amyda  aqua.     Third  neural  and  costal  of  type.     X  i.  ■ 

3.  Amyda  aqua.     Portion  of  middle  of  costal.     X  i. 

Plate  100. 

1.  Amyda  uintensis.     Plastron  of  type.     X  0.27.     Coll.  Phila  Acad. 

2.  Amyda  scutumantiquum.     Right  hyoplastron  and  hypoplastron  of  type.     X  0.5.     No.  1035 

A.  M.  N.  H. 

3.  Amyda  scutumantiquum.     Part  of  first  and  second  neurals  and  first  and  second  costals 

of  type.     X  I. 

4.  Amyda  scutumantiquum.     Part  of  distal  end  of  a  costal  of  type.     X  i. 

Plate  ioi. 

1.  Amyda  scutumantiquum.     Carapace  of  type.     X  0.3.     No.  1035  A.  M.  N.  H. 

2.  Platypeltis  heteroglypta.     Carapace  of  type.     X  0.38.     No.  1039  A.  M.  N.  H. 

Plate  102. 
Amyda  francisca.     Carapace  of  type.     X  0.4     No.  5936  A.M.  N.  H. 

Plate  103 
Amyda  franciscce.     Plastron  of  type.     X  0.4.     No.  5936  A.  M.  N.  H. 

Plate  104. 

1.  Amyda  salebrosa.    Carapace  of  type.     X  0.3.     No.  3941  A.  M.  N.  H. 

2.  Aspideretes  puercensis.     Right  hyoplastron  and  hypoplastron.    X  0.6.     No.  1202  A.  M.  N.  H. 

3.  Aspideretes  puercensis.     Portion  of  right  xiphiplastron  of  type.     X  0.6. 

4.  Axestemys  byssina.     Left  xiphiplastron.     X  0.43.     U.  S.  N.  M. 

Plate  105. 

1.  Amyda  mira.    Carapace  of  type.     X  0.5.     No.  6130  A.  M.  N.  H, 

2.  Temnotrionyx  manducans.     Part  of   right   maxilla   of   type,   side   view.     X  i.     No.  5929 

A.  M.  N.  H. 
J.  Temnotrionyx  manducans.     Same  maxilla,   showing  grinding  surface.     X  i. 


r68  fossil  turtles  of  north  america. 

Plate  io6. 
Amyda  mira.    Plastron  of  type.     X  0.7. 

Plate  107. 

1.  Amyda  egregia.    Carapace  of  type.     X  0.4.    No.  1186  A.  M.  N.  H. 

2.  Amyda  egregia.     Part  of  fourth  and  fifth  neurals  and  fourth  and  fifth  costals.    Type.    X  i. 

Plate  108. 
Amyda  crassa.    Carapace  of  type.     X  0.32.     No.  3887  A.  M.  N.  H. 

Plate  109. 

1.  Platypeltis  serialis.  Carapace.     X  0.75.     In  A.  M.  N.  H. 

2.  Platypeltis  serialis.  Plastron.     X  0.75.     No.  5944  A.  M.  N.  H. 

3.  Platypeltis  serialis.  Plastron.     X  0.75.     No.  6014  A.  M.  N.  H. 

4.  Platypeltis  serialis.  Distal  end  of  costals.     X  i.     No.  5944  A.  M.  N.  H. 

Plate  iio. 

1.  Platypeltis  trionychoides.     Carapace.     X  0.75.     No.  5938  A.  M.  N.  H. 

2.  Platypeltis  trionychoides.     Plastron.     X  0.75.     No.  5938  A.  M.  N.  H. 

Plate  hi. 

1.  Platypeltis  postera.     Carapace   of   type.     X  0.32.     No.  6133  A.  M.  N.  H. 

2.  Platypeltis  postera.     Plastron  of  type.     X  0.32. 

Plate  112. 
Platypeltis  extensa.     Carapace  of  type.     X  0.4.     No.  5951  A.  M.  N.  H. 

Plate  113. 

1.  Platypeltis  leucopotamica.     Carapace.     X  ^.     No.  6045  A.  M.  N.  H. 

2.  Platypeltis  leucopotamica.     Part  of  third  neural  and  costal.     X  i.     No.  6045  A.  M.  N.  H. 

3.  Platypeltis  leucopotamica.     Distal   end   of   second   costal.     X  i.     No.  6045  A.  M.  N.  H. 


Fossil  Turtles 


Plate  I 


Figs.  I  to  4.     Colpochelys  kempi.     X  §•     Page  8. 
Fig.  5.     Platypeltis  ferox.     X  §•     Page  11. 


Fossil  Turtles 


Plate  a 


Lj^p^ 


Colpochelys  kempi.     X  §•    Page  8. 


Fossil  Turtles 


Plate  3 


Platypeltis  ferox.     X  §•    Page  ii. 


Fossil  Turtles 


Plate  4 


Podocnemis  expansa.    Figs,  i  and  2,  X§;  Figs.  3.  4.  and  5,  X  i-    Page  14. 


Fossil  Turtles 


Plate  5 


Glyptops  plicatulus.     Figs,  i  to  4,  X  i ;    Fig.  5,  X  i-     Page  47. 


Fossil  Turtles 


Plate  6 


Glyptops  plicatulus.     X  i-    Page  47. 


Fossil  Turtles 


Plate  7 


Figs.  I  and  2.    Glyptops  caelatus.     X  1.    Page  52. 

Figs.  3  and  4.    Glyptops?    belviderensis.     X  i-    Page  53. 

Fig.  5.     Probaena  sculpta.     X  i-    Page  58. 


Fossil  Turtles 


Plate  8 


SS 

8.S. 
M   Id 

id  t^ 

XX 


1 


g 

c  e 


Fossil  Turties 


Plate  9 


Baena  hatcheri.     X  r    Page  63. 


Fossil  Turtles 


Plate  10 


Baena  hatcheri.    X  I    Page  63. 


Fossil  Turtles 


Plate  II 


u 

bO 

a 


X 

<j 
•o 
ea 

> 

u 

D) 
V 

18 

:S 

n 


Fossil  Turtles 


Plate  12 


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Baena  arenosa.     X  h     Page  68. 


Fossil  Turtles 


Plate  13 


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Fossil  Turtles 


Plate  14 


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Figs.  I  to  3.     Baena  arenosa.     X   i-     Page  69. 
Figs.  4  to  6.     Baena  sima.     X  i-     Page  72. 


Fossil  Turtles 


Plate  IS 


Baena  sima.     X  i-    Page  73. 


Fossil  Turtles 


Plate  i6 


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Fossil  Turtles 


'  Plate  17 


Baena  riparia.     X  f  •    Page  76. 


Fossil  Turtles 


Plate  i8 


Baena  riparia.    X  J.    Page  77. 


Fossil  Turtles 


Plate  19 


Figs.  I  to  3.  Baena  riparia.     X   1.     Page  78. 
Fig.  4.  Eubaena  cephalica.     X  i-    Page  82. 


Fig.  5.  Testudo  vaga.     X  i-    Page  415. 

Figs.  6  and  7.  Testudo  orthopygia.     X  i-     Page  446. 


Fossil  Turtles 


Plate  20 


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Fossil  Turtles 


Plate  21 


Figs.  I  and  2.  Eubaena  cephalica.     X  i-    Page  82. 
Figs.  3  and  4.  Chisternon  hebraicum.     X   i-     Page  88. 


Fossn  Turtles 


Plate  aa 


Chisternon  undatum.     X  0.34.    Page  85. 


Fossil  Turtles 


Plate  33 


Fig.  I.  Chisternon  hebraicum.     X  i-    Page  88.        Figs.  2  and  3.  Bothremys  cooki.     X  f.    Page  103. 
Figs.  4  to  7.  Osteopygis  chelydrinus.     X  i-    Page  136. 


Fossil  Turtles 


Plate  24 


Thescelus  insiliens.     X  i-    Page  95. 


Fossil  Turtles 


Plate  25 


Thescelus  insiliens.     X  J-     Page  95. 


Fossil  Turtles 


Plate  26 


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Fossil  Turtles 


Plate  28 


Figs.  I  to  4.  Osteopygis  chelydrinus.     X  i-    Page  136. 
Figs,  sand  6.  Lytoloma  angusta.     X  h    Page  155. 
Figs.  7  and  8.  Lytoloma  wielandi.    X  f-    Page  157. 


Fossil  Turtles 


Plate  29 


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Plate  30 


Toxochelys  sp.  indet.    X  h    Page  164. 


Fossil  Turtles 


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Fossil  Turtles 


Plate  32 


Figs,  land  2.  Syllomus  crispatus.     X  |.    Page  an.  Fig.  4.  Basilemys  variolosa.     X  i-    Page  226. 

Fig.  3.  Chelonia?  parvitecta.     X  h    Page  220.  Figs.  5  to  7.  Basilemys  itnbricata.     X  i-     Page  231. 


Fossil  Turtles 


Plate  33 


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Fossil  Turtles 


Plate  34 


Fig.  I.  Basilemys  variolosa.     X   i-     Page  226.  Fig- 5-  Adocus  punctatus.  X  i-     Page  238. 

Figs.  2  and  3.  Compsemys  victa.     X   i.     Page  234.       Fig.  6.  Adocus  beatus.     X  J.  Page  240. 

Fig.  4.  Compsemys  ?  obscura.     X  i-     Page  235.  Fig.  7.  Adocus  beatus.     X  h  Page  240. 

Fig.  8.  Adocus  lacer.     Xh     Page  242. 


Fossil  Turtles 


Plate  35 


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Fossil  Turtles 


Plate  36 


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Fig.  I.  Adocus  lacer.     X  h     Page  241- 

Fig.  2.  Adocus  syntheticus.     X  i-    Page  244. 


Fig.  3.  Adocus  agilis.     X  i-     Page  246. 

Fig.  4.  Agomphus  petrosus.     X  h    Page  250. 


Fossi!  Turtles 


Plate  37 


Figs.  I  to  5.  Agomphus  turgidus.     X  J-     Page  249.  Figs.  8  and  9.  Agomphus  pectoralis.     X  i-     Page  254. 

Figs.  6  and  7.  Agomphus  petrosus.     X  i-     Page  250.        Fig.  10.  Zygoramma  striatula.    X  S-    Page  258. 

Figs.  II  to  13.  Baptemys  wyomingensis.     X  h    Page  273. 


Fossil  Turtles 


Plate  38 


Figs.  I  to  3.  Zygoramma  striatula.     X  h     Page  257.         Figs.  4  to  9.  Hoplochelys  crassa.     X   i-     Page  263. 

Fig.  10.  Baptemys  wyomingensis.     X  i-     Page  273. 


Fossil  Turtles 


Plate  39 


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Fossil  Turtles 


Plate  40 


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Fig.  I.     Baptemys  wyomingensis.     X  h     Page  271. 
Figs.  2  and  3.    Naomichelys  speciosa.    X  I-    Page  loi. 


Fossil  Turtles 


Plate  41 


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Fossil  Turtles 


Plate  42 


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Fossil  Turtles 


Plate  43 


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Fossil  Turtles 


Plate  44 


Gyremys  spectabilis.     X  i-    Page  288. 


Fossil  Turtles 


Plate  45 


Figs.  I  to  3.  Clemmys  morrisiae.     X  J.     Page  290.       Figs.  11  to  13.  Echmatemys  sp.  indet.     Xi.     Page  297. 
Figs.  4  to  7.  Clemmys  hesperia.     X  i-     Page  292.        Figs.  14  and  15.  Echmatemys  megaulax.     X  i.     Page  302. 
Figs.  8  to  10.  Clemmys  saxea.     X  i-    Page  294.  Figs.  16  and  17.  Echmatemys  testudinea.     X  f.    Page  303. 


Fossil  Turtles 


Plate  46 


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Fossil  Turtles 


Plate  47 


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Fossil  Turtles 


Plate  48 


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Fossil  Turtles 


Plate  49 


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Plate  53 


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Plate  53 


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Fossil  Turtles 


Plate  54 


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Figs.  I  and  2.  Deirochelys  floridana.     X  f-    Page  346.     Figs.  4  to  9.  Trachemys  sculpta.     X  t-    Page  351. 
Fig.  3.  Trachemys  euglypha  ?     X  f  •     Page  351.  Figs.  10  to  12.  Trachemys  jarmani.     X  I-     Page  351. 

Fig.  13.  Pseudemys  extincta.     X  |.  Page  356. 


Fossil  Turtles 


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Plate  56 


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Pseudemys  caelata.     X  i-    Page  356. 


Fossil  Turtles 


Plate  58 


Terrapene  marnochi.     X  !•    Page  362. 


Fossil  Turtles 


Plate  59 


Fig.  I.     Hadrianus  majusculus.     X  i-     Page  374. 
Figs.  2  to  4.    Stylemys  nebrascensis.     X  !•    Page  388. 


Fossil  Turtles 


Hadrianus  corsoni.     X  !•     Page  377- 


Fossil  Turtles 


Plate  6x 


Hadrianus  corsoni.    X  i-    Page  378. 


Fossil  Turtles 


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Fossil  Turtles 


Plate  63 


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Fossil  Turtles 


Plate  64 


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Fossil  Turtles 


Plate  65 


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Fossil  Turtles 


Plate  66 


Figs.  I  to  s.  Testudo  thomsoni.    Fig.  i,     X  i;     Figs.  2  to  s,  X  i-  Page  400. 
Figs.  6  and  7.  Testudo  exornata.    X  i-    Page  40i. 


Fossil  Turtles 


Plate  67 


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Fossil  Turtles 


Plate  68 


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Fossil  Turtles 


Plate  69 


Testudo  farri.     X  i-    Page  418. 


Fossil  Turtles 


Plate  70 


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Fossil  Turtles 


Plate  71 


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Fossil  Turtles 


Plate  72 


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Testudo  osborniana.    X  i-    Page  423. 


Fossil  Turtles 


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Testudo  osborniana.     X  h    Page  424. 


Fossil  Turtles 


Plate  74 


Testudo  osborniana.    X  i-    Page  427. 


Fossil  Turtles 


Plate  75 


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Fossil  Turtles 


Plate  76 


Testudo  impensa.    X  i-    Page  433- 


Fossil  Turtles 


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Testudo  impensa.     X  i-    Page  433. 


Fossil  Turtles 


Plate  78 


C?     I 


Testudo  orthopygia.    Fig.  i,     X  J;    Fig- 2,    X  i-    Page  440. 


Fossil  Turtles 


Plate  79 


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Fossil  Turtles 


Plate  83 


Fig.  1.  Testudo  orthopygia.    X  i-    Page  448. 
Figs.  2  to  5.  Testudo  gilbertL    X  i-    Page  449. 


Fossil  Turtles 


Plate  8i 


Testudo  orthopygia.     X  i-    Page  448. 


Fossil  Turtles 


Plate  83 


Testudo  orthopygia.    X  i-    Page  448. 


Fossil  Turtles 


Plate  83 


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Fossil  Turtles 


Plate  84 


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Fossil  Turtles 


Plate  85 


Figs.  I  and  2.  Plastomenus  costatus.     X  i-    Page  468. 
Fig.  3.  Plastomenus  molopinus.     X  i-    Page  482. 


Fossil  Turtles 


Plate  86 


Fig.  I.  Plastomenus  catenatus.    X  i-    Page  470. 
Fig.  2.  Plastomenus  ?  leptomitus.    X  i-    Page  471. 
Figs.  3  and  3a.  Plastomenus  ?  lachrjrmalis.    X  !•    Page  47a. 
Fig.  4.  Plastomenus  ?  fractus.    X  i-    Page  472. 


Fig.  5.  Plastomenus  corrugatus.  X  !•  Page  473. 
Figs.  6a  and  6b  to  8.  Plastomenus  communis.  X  i- 
Figs.  9  and  10.  Amyda  ?  cariosa.  X  i-  Page  516. 
Figs.  II  and  13.  Amyda  radula.    X  !•    Page  517. 


Page  473. 


Fossil  Turtles 


Plate  87 


1 
Plastomenus  visendus.     X  i-    Page  477. 


Fossil  Turtles 


Plate  88 


Figs.  I  to  3.  Conchochelys  admirabilis.     X  i- 
Figs.  4  and  5.    Helopanoplia  distincta.     X  i- 


Page  483.      Fig.  6.  Aspideretes  coalescens.     X  i-    Page  490. 
Page  485.      Figs.  7  to  g.  Aspideretes  splendidus.     X  i-    Page  491. 


Fossil  Turtles 


Aspideretes  f oveatus.    Fig.  i,     X  i;    Fig.  2,     X  i.     Page  487. 


Fossil  Turtles 


Plate  go 


Fig.  I.  Aspideretes  coalescens.     X  i-    Page  490. 
Fig.  2.  Aspideretes  beecheri.     X  i-    Page  493. 


Fossil  Turtles 


Fossil  Turtles 


Plate  92 


W  I    ; 


Aspideretes  beecheri.     X  i-    Page  492. 


Fossil  Turtles 


Aspideretes  foveatus.  Fig.  i,    X  ii    Figs.  2  and  3,    X  i-    Page  497. 


Fossil  Turtles 


Plate  94 


Aspideretes puercensis.  Fig.  i,    X  J;    Figs. sands,    X  !•    Page  499. 


Fossil  Turtles 


Plate  95 


Aspideretes  ellipticus.    Fig.  i,    X  f;    Figs.  2  and  3,    X  i-    Page  505. 


Fossil  Turtles 


Plate  96 


Figs.  I  and  2.  Aspideretes  beecheri.    X  i-    Page  492-  Figs.  4  and  5.  Amyda  ?  halophila.    X  i.    Page  513. 

Fig.  3.  Aspideretes  vagans.     X  !•    Page  497.  Fig.  6.  Amyda  ?  pennata.     X  !•    Page  514. 

Figs.  7  and  8.  Amyda?  virginiana.    X  i.    Page  515. 


Fossil  Turtles 


Plate  97 


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Fossil  Turtles 


Plate  gS 


Figs.  I  to  6.  Amyda  ventricosa.     X  i-    Page  516. 
Figs.  7  to  10.  Amyda  concentrica.     X  i-    Page  523. 
Fig.  II.  Amyda  lima.     X  i-     Page  533. 


Fig.  12.  Amyda  buiei.     X  !•    Page  534. 
Fig.  13.  Platypeltis  serialis.     X  i.     Page  538. 
Fig.  14.  Platypeltis  beteroglypta.     X  i>    Page  544- 


Fossil  Turtles 


Amydaaqua.    Fig.  i,    X  0.3;  Figs,  a  and  3,    X  i-    Page  518. 


Fossil  Turtles 


Plate  100 


Fig.  I.  Amyda  uintensis.     X  o-27-     Page  521. 
Figs.  2  to  4.  Amyda  scutumantiquum.    Fig.  2,     X  J;  Figs.  3  and  4,     X  1.    Page  521. 


Fossil  Turtles 


Plate  loi 


Fossil  Turtles 


Plate  102 


Amyda  franciscae.     X  0.4.     Page  523. 


Fossil  Turtles 


Plate  103 


Amyda  franciscae.    X  0.4.    Page  524. 


Fossil  Turtles 


Plate  104 


Fossil  Turtles 


Plate  105 


Fig.  1.  Amyda  mira.    X  i-    Page  527. 

Figs.  2  and  3.  Temnotrionyx  manducans.    X  i-    Page  535. 


Fossil  Turtles 


Plate  io6 


aa 
a 


o 
X 


n 
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>> 

B 
< 


Fossil  Turtles 


Plate  107 


Amyda  egregia.    Fig.  i,    X  0.4;  F»gs.  2  ands,    X  i-    Page  531. 


Fossil  Turtles 


Amyda  crassa.     X  0.32.    Page  532. 


Fossil  Turtles 


Plate  log 


Platypeltis  serialis.    Figs,  i  to  3.    Xi;Fifr4,    X  i.    Page  539. 


Fossil  Turtles 


Plate  no 


Platypeltis  trionychoides.     X  I-    Page  54a- 


Fossil  Turtles 


Plate  III 


Platypeltis  postera.    X  0.32.    Page  545. 


Fossil  Turtles 


Plate  112 


Platypeltis  extensa.     X  0.4.    Page  546. 


Fossil  Turtles 


Plate  113 


Platypeltis  leucopotamica.     Fig.  i,     X  J;     Figs.  2  and  3,     X  i.     Page  547. 


I 


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